Impact of Epicardial Adipose Tissue on Infarct Size and Left Ventricular Systolic Function in Patients with Anterior ST-Segment Elevation Myocardial Infarction

We aimed to assess the correlation of cardiovascular magnetic resonance (CMR)-derived epicardial adipose tissue (EAT) with infarct size (IS) and residual systolic function in ST-segment elevation myocardial infarction (STEMI). We enrolled patients discharged for a first anterior reperfused STEMI submitted to undergo CMR. EAT, left ventricular (LV) ejection fraction (LVEF), and IS were quantified at the 1-week (n = 221) and at 6-month CMR (n = 167). At 1-week CMR, mean EAT was 31 ± 13 mL/m2. Patients with high EAT volume (n = 72) showed larger 1-week IS. After adjustment, EAT extent was independently related to 1-week IS. In patients with large IS at 1 week (>30% of LV mass, n = 88), those with high EAT showed more preserved 6-month LVEF. This association persisted after adjustment and in a 1:1 propensity score-matched patient subset. Overall, EAT decreased at 6 months. In patients with large IS, a greater reduction of EAT was associated with more preserved 6-month LVEF. In STEMI, a higher presence of EAT was associated with a larger IS. Nevertheless, in patients with large infarctions, high EAT and greater subsequent EAT reduction were linked to more preserved LVEF in the chronic phase. This dual and paradoxical effect of EAT fuels the need for further research in this field.

Short-Course High-Intensity Statin Treatment during Admission for Myocardial Infarction and LDL-Cholesterol Reduction-Impact on Tailored Lipid-Lowering Therapy at Discharge

We hypothesized that a short-course high-intensity statin treatment during admission for myocardial infarction (MI) could rapidly reduce LDL-C and thus impact the choice of lipid-lowering therapy (LLT) at discharge. Our cohort comprised 133 MI patients (62.71 ± 11.3 years, 82% male) treated with atorvastatin 80 mg o.d. during admission. Basal LDL-C levels before admission were analyzed. We compared lipid profile variables before and during admission, and LLT at discharge was registered. Achieved theoretical LDL-C levels were estimated using LDL-C during admission and basal LDL-C as references and compared to LDL-C on first blood sample 4-6 weeks after discharge. A significant reduction in cholesterol from basal levels was noted during admission, including total cholesterol, triglycerides, HDL-C, non-HDL-C, and LDL-C (-39.23 ± 34.89 mg/dL, p < 0.001). LDL-C levels were reduced by 30% in days 1-2 and 40-45% in subsequent days (R2 0.766, p < 0.001). Using LDL-C during admission as a reference, most patients (88.7%) would theoretically achieve an LDL-C < 55 mg/dL with discharge LLT. However, if basal LDL-C levels were considered as a reference, only a small proportion of patients (30.1%) would achieve this lipid target, aligned with the proportion of patients with LDL-C < 55 mg/dL 4-6 weeks after discharge (36.8%). We conclude that statin treatment during admission for MI can induce a significant reduction in LDL-C and LLT at discharge is usually prescribed using LDL-C during admission as the reference, which leads to insufficient LDL-C reduction after discharge. Basal LDL-C before admission should be considered as the reference value for tailored LLT prescription.

Novel Targets Regulating the Role of Endothelial Cells and Angiogenesis after Infarction: A RNA Sequencing Analysis

Endothelial cells (ECs) are a key target for cardioprotection due to their role in preserving cardiac microvasculature and homeostasis after myocardial infarction (MI). Our goal is to identify the genes involved in post-MI EC proliferation, EC apoptosis, and angiogenesis regulation via RNA-sequencing transcriptomic datasets. Using eight studies from the Gene Expression Omnibus, RNA-sequencing data from 92 mice submitted to different times of coronary ischemia or sham were chosen. Functional enrichment analysis was performed based on gene ontology biological processes (BPs). Apoptosis-related BPs are activated up to day 3 after ischemia onset, whereas endothelial proliferation occurs from day 3 onwards, including an overrepresentation of up to 37 genes. Endothelial apoptosis post-MI is triggered via both the extrinsic and intrinsic signaling pathways, as reflected by the overrepresentation of 13 and 2 specific genes, respectively. BPs implicated in new vessel formation are upregulated soon after ischemia onset, whilst the mechanisms aiming at angiogenesis repression can be detected at day 3. Overall, 51 pro-angiogenic and 29 anti-angiogenic factors displayed altered transcriptomic expression post-MI. This is the first study using RNA sequencing datasets to evaluate the genes participating in post-MI endothelium physiology and angiogenesis regulation. These novel data could lay the groundwork to advance understanding of the implication of ECs after MI.

Changes in the extracellular matrix at microvascular obstruction area after reperfused myocardial infarction: A morphometric study

BACKGROUND

Extracellular matrix (ECM) suffers substantial alterations after myocardial infarction (MI), including the invasion of leukocyte subtypes. Despite a complete reopening at epicardial level, hypoperfusion within the infarcted myocardium, known as microvascular obstruction (MVO), occurs and exerts a negative impact on ventricular remodeling. In this study, ECM composition at MVO regions was described using a morphometric analysis.

METHODS

MI was induced in female swine (n = 10) by transitory 90-minute coronary occlusion followed by seven days of reperfusion. Prior to euthanasia, intracoronary thioflavin-S was infused. Within the infarcted myocardium, regions displaying MVO (thioflavin-S-) or no MVO (thioflavin-S+) were isolated and stained to morphometrically compare ECM composition.

RESULTS

As reflected by cell invasion through ECM, areas with MVO displayed an enlarged presence of neutrophils and lymphocytes, whilst no differences in the amount of macrophages and myofibroblasts were detected compared to infarcted myocardium without MVO. Indeed, those regions with macroscopic MVO showed lower capillary density than areas without MVO. Lastly, a significant reduction in the extension of total collagen, type I, but not type III, collagen, laminin, and fibronectin together with an augmentation of polysaccharides were noted in areas showing MVO compared to those without microvascular injury.

CONCLUSIONS

ECM composition in infarcted regions with MVO isolated from female swine displays a higher presence of inflammatory infiltrate and polysaccharides as well as reduced number of microvessels and collagen content compared to those areas without microvascular hypoperfusion. These characteristics might underlie the development of adverse ventricular remodeling in MI patients with extensive MVO.

Impact of Persistent Microvascular Obstruction Late After STEMI on Adverse LV Remodeling: A CMR Study

BACKGROUND

Little is known about the occurrence and implications of persistent microvascular obstruction (MVO) after reperfused ST-segment elevation myocardial infarction (STEMI).

OBJECTIVES

The authors used cardiac magnetic resonance (CMR) to characterize the impact of persistent MVO on adverse left ventricular remodeling (ALVR).

METHODS

A prospective registry of 471 STEMI patients underwent CMR 7 (IQR: 5-10) days and 198 (IQR: 167-231) days after infarction. MVO (≥1 segment) and ALVR (relative increase >15% at follow-up CMR) of left ventricular end-diastolic index (LVEDVI) and left ventricular end-systolic volume index (LVESVI) were determined.

RESULTS

One-week MVO occurred in 209 patients (44%) and persisted in 30 (6%). Extent of MVO (P = 0.026) and intramyocardial hemorrhage (P = 0.001) at 1 week were independently associated with the magnitude of MVO at follow-up CMR. Compared with patients without MVO (n = 262, 56%) or with MVO only at 1 week (n = 179, 38%), those with persistent MVO at follow-up (n = 30, 6%) showed higher rates of ALVR-LVEDVI (22%, 27%, 50%; P = 0.003) and ALVR-LVESVI (20%, 21%, 53%; P < 0.001). After adjustment, persistent MVO at follow-up (≥1 segment) was independently associated with ΔLVEDVI (relative increase, %) (P < 0.001) and ΔLVESVI (P < 0.001). Compared with a 1:1 propensity score-matched population on CMR variables made up of 30 patients with MVO only at 1 week, patients with persistent MVO more frequently displayed ALVR-LVEDVI (12% vs 50%; P = 0.003) and ALVR-LVESVI (12% vs 53%; P = 0.001).

CONCLUSIONS

MVO persists in a small percentage of patients in chronic phase after STEMI and exerts deleterious effects in terms of LV remodeling. These findings fuel the need for further research on microvascular injury repair.

Cardiac magnetic resonance outperforms echocardiography to predict subsequent implantable cardioverter defibrillator therapies in ST-segment elevation myocardial infarction patients

Background

Implantable cardioverter defibrillators (ICD) are effective as a primary prevention measure of ventricular tachyarrhythmias in patients with ST-segment elevation myocardial infarction (STEMI) and depressed left ventricular ejection fraction (LVEF). The implications of using cardiac magnetic resonance (CMR) instead of echocardiography (Echo) to assess LVEF prior to the indication of ICD in this setting are unknown.

Materials and methods

We evaluated 52 STEMI patients (56.6 ± 11 years, 88.5% male) treated with ICD in primary prevention who underwent echocardiography and CMR prior to ICD implantation. ICD implantation was indicated based on the presence of heart failure and depressed LVEF (≤ 35%) by echocardiography, CMR, or both. Prediction of ICD therapies (ICD-T) during follow-up by echocardiography and CMR before ICD implantation was assessed.

Results

Compared to echocardiography, LVEF was lower by cardiac CMR (30.2 ± 9% vs. 37.4 ± 7.6%, p < 0.001). LVEF ≤ 35% was detected in 24 patients (46.2%) by Echo and in 42 (80.7%) by CMR. During a mean follow-up of 6.1 ± 4.2 years, 10 patients received appropriate ICD-T (3.16 ICD-T per 100 person-years): 5 direct shocks to treat very fast ventricular tachycardia or ventricular fibrillation, 3 effective antitachycardia pacing (ATP) for treatment of ventricular tachycardia, and 2 ineffective ATP followed by shock to treat ventricular tachycardia. Echo-LVEF ≤ 35% correctly predicted ICD-T in 4/10 (40%) patients and CMR-LVEF ≤ 35% in 10/10 (100%) patients. CMR-LVEF improved on Echo-LVEF for predicting ICD-T (area under the curve: 0.76 vs. 0.48, p = 0.04).

Conclusion

In STEMI patients treated with ICD, assessment of LVEF by CMR outperforms Echo-LVEF to predict the subsequent use of appropriate ICD therapies.

Meta-Analysis of Extracellular Matrix Dynamics after Myocardial Infarction Using RNA-Sequencing Transcriptomic Database

Extracellular matrix (ECM) changes after myocardial infarction (MI) need precise regulation, and next-generation sequencing technologies provide omics data that can be used in this context. We performed a meta-analysis using RNA-sequencing transcriptomic datasets to identify genes involved in post-MI ECM turnover. Eight studies available in Gene Expression Omnibus were selected following the inclusion criteria. We compare RNA-sequencing data from 92 mice submitted to permanent coronary ligation or sham, identifying differentially expressed genes (p-value < 0.05 and Log2FoldChange ≥ 2). Functional enrichment analysis was performed based on Gene Ontology biological processes (BPs). BPs implicated in response to extracellular stimulus, regulation of ECM organization, and ECM disassembly were detected soon after ischemia onset. ECM disassembly occurred between days one to seven post-MI, compared with ECM assembly from day seven onwards. We identified altered mRNA expression of 19 matrix metalloproteinases and four tissue inhibitors of metalloproteinases at post-infarcted ECM remodeling and altered transcriptomic expression of 42 genes encoding 26 collagen subunits at the fibrotic stage. To our knowledge, this is the first meta-analysis using RNA-sequencing datasets to evaluate post-infarcted cardiac interstitium healing, revealing previously unknown mechanisms and molecules actively implicated in ECM remodeling post-MI, which warrant further validation.

Sex Effect in the Decision to Perform Invasive Coronary Angiography in Patients With Chronic Coronary Syndrome After Undergoing Vasodilator Stress MRI

BACKGROUND

Stress cardiac MRI permits comprehensive evaluation of patients with known or suspected chronic coronary syndromes (CCS). The impact of sex on the use of invasive cardiac angiography (ICA) after vasodilator stress cardiac MRI is unclear.

PURPOSE

To evaluate the impact of sex on ICA use after vasodilator stress cardiac MRI.

STUDY TYPE

Retrospective.

POPULATION

A total of 6229 consecutive patients (age [mean ± standard deviation] 65.2 ± 11.5 years, 38.1% women).

FIELD STRENGTH/SEQUENCE

A 5-T; a steady-state free-precession cine sequence; stress first-pass perfusion imaging; late enhancement imaging.

ASSESSMENT

Patients underwent vasodilator stress cardiac MRI for known or suspected CCS. The ischemic burden (at stress first-pass perfusion imaging) was computed (17-segment model).

STATISTICAL TESTS

Multivariate logistic regression was used to evaluate the potential differential association between ischemic burden and use of cardiac MRI-related ICA across sex.

RESULTS

A total of 1109 (17.8%) patients were referred to ICA, among which there were significantly more men (762, 19.7%) than women (347, 14.6%). Overall, after multivariate adjustment, female sex was not associated with lower use of ICA (odds ratio [OR] = 0.99; confidence interval [CI] 95%: 0.84-1.18, P = 0.934). However, significant sex differences were detected across ischemic burden. Whereas women with nonischemic vasodilator stress cardiac MRI (0 ischemic segments) were less commonly submitted to ICA (OR = 0.49; CI 95%: 0.35-0.69) in patients with ischemia (>1 ischemic segment), adjusted use of ICA was more frequent in women than men (OR = 1.27; CI 95%: 1.1-1.5).

DATA CONCLUSIONS

In patients with known or suspected CCS submitted to undergo vasodilator stress cardiac MRI, cardiac MRI-related ICA may be overused in men without ischemia. Furthermore, ICA referral in patients with negative ischemia resulted in greater odds of revascularization in men.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 5.

Risk of death associated with incident heart failure in patients with known or suspected chronic coronary syndrome

AIMS

Traditional adverse events in chronic coronary syndrome (CCS) include atherothrombotic events but usually exclude heart failure (HF). Data are scarce about how new-onset HF modifies mortality risk. We aimed to determine the incidence of HF and compare its long-term mortality risk with myocardial infarction (MI) and stroke in patients with known or suspected CCS.

METHODS

We prospectively evaluated 5811 consecutive HF-free patients submitted to vasodilator stress cardiac magnetic resonance (CMR) for known or suspected CCS. Ischaemic burden and left ventricular ejection fraction were assessed by CMR. HF included outpatient diagnosis or acute HF hospitalization. The mortality risk for the incident events and their cross-comparisons were evaluated using a Markov illness-death model with transition-specific survival models.

RESULTS

The mean age was 55 ± 11 years, and 38.9% were female. At a median follow-up of 5.44 (IQR = 2.53-8.55) years, 591 deaths were registered (1.79 per 100 P-Y). The rates of new-onset HF were higher compared with MI and stroke [1.02, 0.62, and 0.51, respectively (P < 0.05)]. The adjusted association between new-onset HF, MI, and stroke, and subsequent mortality was time dependent. The risk increased almost linearly for HF and became significant by the third year. By Year 10, the mortality risk attributable to new-onset HF was more than 2.5-fold (HR: 2.68, 95% CI = 1.74-4.12). For MI, there was a significant increase in mortality risk up to the second year, followed by a monotonic decrease. For stroke, the mortality risk increased for the entire follow-up but became significant by the third year. A cross-comparison among incident endpoints HF outnumbers risk for those with MI by the sixth year (HR_year6.3 : 1.88, 95% CI = 1.03-3.43). There was no difference in mortality risk between incident HF and stroke.

CONCLUSIONS

In patients with CCS, long-term rates of incident HF were higher than MI and stroke. Patients with new-onset HF showed a higher risk of long-term mortality.

Prognostic value of cardiac magnetic resonance in elderly patients soon after ST-segment elevation myocardial infarction

Background

Elderly patients with ST-segment elevation myocardial infarction (STEMI) represent a very high-risk population. Data on the prognostic value of cardiac magnetic resonance (CMR) in this scenario are scarce.

Purpose

We aim to study the prognostic value of an early (1-week) CMR in elderly patients after STEMI and to create a simple risk score including clinical and CMR variables.

Methods

The registry comprised 247 patients over 70 years of age discharged for a first STEMI treated with percutaneous intervention and included in a multicenter registry. Baseline characteristics, echocardiographic parameters and CMR-derived left ventricular ejection fraction (LVEF, %), infarct size (% of left ventricular mass) and microvascular obstruction (MVO, number of segments) were prospectively collected. The additional prognostic power of CMR was assessed using adjusted C-statistic, net reclassification index (NRI) and integrated discrimination improvement index (IDI).

Results

During a 4.8-year mean follow-up, 66 (26.7%) first major adverse cardiac events (MACE) occurred (27 all-cause deaths and 39 re-admissions for acute heart failure). Higher GRACE score (HR 1.03 [1.02–1.04], p&lt;0.001), more depressed CMR-LVEF (HR 0.97 [0.95–0.99] per increased %, p=0.006) and more extensive MVO (HR 1.24 [1.09–1.4] per segment, p=0.001) predicted MACE occurrence. The addition of CMR data significantly improved MACE prediction compared to the model with baseline and echocardiographic characteristics (C-statistic 0.759 [0.694–0.824] vs. 0.685 [0.613–0.756], NRI=0.6, IDI=0.08, p&lt;0.001). The best cut-offs for independent variables were GRACE score &gt;155, LVEF &lt;40%, and MVO ≥2 segments. A simple score (0, 1, 2, and 3) based on the number of altered factors accurately predicted the MACE per 100 person-years: 0.78, 5.53, 11.51 and 78.79, respectively (p&lt;0.001).

Conclusions

CMR data contribute valuable prognostic information in elderly patients submitted to undergo CMR soon after STEMI.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Instituto de Salud Carlos III and “Fondos Europeos de Desarrollo Regional FEDER” and Conselleria de Educaciόn – Generalitat Valenciana.

Cardiac magnetic resonance characterization and prediction of left ventricular thrombus after ST-segment elevation myocardial infarction

Background

Left ventricular thrombus (LVTh) is an uncommon yet serious complication after ST-segment elevation myocardial infarction (STEMI). Late gadolinium enhancement (LGE) sequences in cardiac magnetic resonance (CMR) imaging allows for accurate detection of LVTh. However, the implications of CMR to predict and characterize LVTh occurrence is this population is unclear.

Purpose

We aim to characterize the incidence, outcomes, and predictors of LVTh after STEMI by CMR imaging.

Methods

Our registry comprised 455 patients admitted for a first reperfused STEMI in our university hospital. Baseline characteristics were recorded. All patients underwent early (1-week) and late (6-month) CMR. Left ventricular ejection fraction (LVEF, %), infarct size (% of left ventricular mass) and microvascular obstruction (MVO, number of segments) were measured. LGE sequences were used to analyze the presence of LVTh. Patients with LVTh at 6-month CMR underwent an additional CMR 1 year after admission. Univariate and multivariate comparisons were performed to study the ocurrence of LVTh in the first 6 months after STEMI.

Results

Mean age was 58.24±11.69 years, most patients were male (82.6%) and anterior infarction occurred in more than half of the cohort (52.7%). LVTh was detected in 36 (7.9%) patients in the first 6 months after STEMI. Anticoagulation was initiated in all cases. Of these, 27 patients had LVTh at early (1-week) CMR, but 9 had LVTh at late (6-month) CMR with no prior evidence of LVTh at early CMR. A total of 6 patients had persisting LVTh at 1-year CMR (37.5% of patients with 6-month LVTh). In multivariable analysis, anterior infarction (HR 6.6 [1.91–22.83], p&lt;0.001) and 1-week CMR-LVEF (HR 0.97 [0.93–0.99], p=0.04) and MVO (HR 1.19 [1.02–1.39], p=0.03) independently predicted the occurrence of LVTh in the first 6 months after STEMI. We computed a risk score of LVTh assigning 1 point to each of these variables (anterior infarction, CMR-LVEF &lt;50% and MVO &gt;3.5 segments), which allowed us to stratify the risk of LVTh in the first 6 months after STEMI (0.6% if 0 points, 3.8% if 1 point, 14.4% if 2 points, and 31.2% if 3 points).

Conclusions

CMR imaging soon after STEMI can contribute relevant prognostic value regarding LVTh occurrence after the acute event. Patients with anterior infarction, LVEF &lt;50% and MVO in &gt;3.5 segments at early (1-week) CMR have the highest risk of LVTh in the first 6 months after STEMI.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Instituto de Salud Carlos III and “Fondos Europeos de Desarrollo Regional FEDER” and Conselleria de Educaciόn – Generalitat Valenciana.

Epicardial adipose tissue, infarct size, microvascular obstruction and ventricular remodelling after ST-segment elevation myocardial infarction

Background

Epicardial adipose tissue (EAT) is a biologically active fat deposit contained beneath the pericardium promoting coronary atherosclerosis. EAT can be accurately measured through cardiac magnetic resonance (CMR), which also enables an accurate quantification of infarct size, microvascular obstruction (MVO), left ventricular (LV) ejection fraction (EF) and volumes in patients with ST-elevation myocardial infarction (STEMI).

Purpose

We performed a systematic assessment of the correlates of EAT volume at baseline and after 6 months in a homogeneous cohort of patients with STEMI.

Methods

We prospectively enrolled patients with a first anterior STEMI reperfused within 12 hours from symptom onset. These patients underwent a first CMR exam after 1 week from the MI and after 6 months.

Results

Patients (n=138) were more often men (81%), with a median age of 58 years (interquartile range 48–66). EAT volume was 30 mL/m2 (23–41). Patients with EAT &gt;30 mL/m2 (n=69) were older (60±12 vs. 55±11 years, p=0.02), more often diabetic (26% vs. 12%, p=0.03), and showed a worse baseline risk profile (Thrombolysis in Myocardial Infarction risk score 3 [2–5] vs. 2 [1–4], p=0.05). Patients with EAT &gt;30 mL/m2 also displayed a larger IS (33±15 vs. 23±16% of LV mass, p=0.001) and MVO (1.5 [0–6.8] vs. 0% [0–2.2], p=0.008). Again in patients with EAT &gt;30 mL/m2, EAT volume independently predicted infarct size (standardized beta coefficient=0.30, p&lt;0.001) and MVO area (standardized beta coefficient=0.36, p&lt;0.001) after adjusting for age, sex and infarct characteristics at 1 week (Figure 1). Despite these correlations with infarct size and MVO, patients with EAT &gt;30 mL/m2 did not display more depressed LVEF or larger LV volumes than those with EAT ≤30 mL/m2, either at 1 week or at 6-month CMR (p&gt;0.1 for all comparisons).

Conclusions

In a cohort of patients with first anterior STEMI undergoing timely reperfusion, those with a greater EAT volume have a larger infarct size and a larger area of MVO. Despite these correlates of EAT volume size, patients with larger EAT do not have a higher risk of adverse LV remodelling.

Funding Acknowledgement

Type of funding sources: None.

Infarction of the papillary muscle is an independent predictor of heart failure, ventricular tachycardia, and consequent mortality

Background

Previous studies have assessed the effect of papillary muscle infarction (papMI) as seen with Late Gadolinium Enhancement (LGE) Cardiac Magnetic Resonance imaging (CMR) after ST-segment elevation myocardial infarction (STEMI) on patient prognosis. As these studies delivered inconclusive results due to limited sample size and follow-up, we set out to assess whether STEMI patients with papMI are at an increased risk of cardiovascular mortality, heart failure, and arrhythmic events.

Methods

This is a 3-center observational study in n=1,055 consecutive STEMI patients who underwent CMR at a median of 6 (4–9) days, with a mean follow-up of 6.0 years (IQR 3.1–9.1 years). Any presence of papMI, be it supero-lateral, infero-medial, or double, was evaluated visually on the LGE images and checked on the matched cine images. The primary outcomes are time to cardiovascular mortality, heart-failure events defined as heart failure death and hospital admission for heart failure, and arrhythmic events, defined as arrhythmic death and ventricular tachycardia (VT).

Results

PapMI was diagnosed in 351 patients (33%). PapMI is an independent predictor of cardiovascular mortality after correction for clinically relevant parameters such as infarct size and left ventricular ejection fraction (Multivariate Cox Regression Hazard Ratio (HR)=2.46, 95% confidence interval (CI) 1.23–4.92). Secondly, papMI independently predicts the combined endpoints of heart failure death/heart failure (HR=1.72, 95% CI 1.12–2.63) and arrhythmic death/ VT (HR=4.52, 95% CI 2.18–9.36).

Conclusions

PapMI predicts cardiovascular mortality, arrhythmic death and heart failure. PapMI should be taken into account, especially when conducting new prognosis studies after STEMI and as a stratification factor in studies for secondary prevention of VT and arrhythmic death.

Funding Acknowledgement

Type of funding sources: Other.

Sex-based differences on adverse left ventricular remodeling and clinical outcomes after an ST-segment elevation myocardial infarction in the PCI era

Background

There is conflicting evidence regarding sex-based differences in myocardial salvage and clinical outcome in patients after an ST-segment elevation myocardial infarction (STEMI) in the contemporary era of primary percutaneous coronary intervention (PCI) and optimal medical treatment.

Adverse left ventricular remodelling (LVR) after a STEMI worsens outcomes, however, the influence of sex is not yet clear.

Aim/Purpose

To analyze whether there are sex differences in clinical outcomes and adverse LVR in patients after a STEMI.

Methods

Patients with STEMI who underwent primary PCI were included and a cardiac magnetic resonance (CMR) was performed during hospitalization (6.2±2.6 days) and after 6 months (6.1±1.8 months). LVR, myocardial salvage (MS), infarct size (IS), microvascular obstruction (MVO), and area at risk (AAR) were quantified. Adverse LVR was defined as a 15% increase in LV end-diastolic volume and a relative fall in LV ejection fraction of 3% at 6 months. The primary outcome was a composite of cardiovascular death, admission for heart failure, or ventricular arrhythmia.

Results

A total of 1046 patients were included (mean age: 59.8±9 years; 16.6% women), and a second CMR was completed in 589 patients. Women were older (58.8±8 years vs 65.0±10 years, p&lt;0.0001) and presented more cardiovascular risk factors (Table). The primary outcome occurred in 310 patients during follow-up of 75 months (range: 36–112 months) and was more frequent in women than in men (35.8% vs 22.3%, p&lt;0.001). After adjusting for baseline differences (age, diabetes, hypertension, Killip class, and time to reperfusion), female sex was not an independent predictor of major adverse cardiac events (Fig. 1A & B).

Although adverse LVR was a strong independent predictor for the primary outcome, no interaction was present between sex and LVR (women 6.4% vs men 8%, p=0.46) (Fig 1B), nor did we find significant differences between sex and other CMR derived variables such as MS, IS, MVO and AAR.

Conclusions

After a STEMI, women present worse clinical outcomes than men. However, these differences are related to their clinical characteristics and higher incidence of cardiovascular risk factors, and not to a higher incidence of adverse left ventricular remodeling.

Funding Acknowledgement

Type of funding sources: None.

A novel clinical and cardiac magnetic resonance risk score for early risk prediction after ST-segment elevation myocardial infarction

Background

Cardiac magnetic resonance (CMR) performed early after ST-segment elevation myocardial infarction (STEMI) can improve major adverse cardiac event (MACE) risk prediction. However, predictive models including clinical and CMR variables are scarce and not routinely implemented in clinical practice.

Purpose

We aimed to create a simple clinical-CMR risk score for early MACE risk stratification in STEMI patients.

Methods

We performed a multicenter prospective registry in three Spanish university hospitals of reperfused STEMI patients (n=1118) in whom early (1-week) CMR-derived left ventricular ejection fraction (LVEF), infarct size and microvascular obstruction (MVO) were quantified. MACE was defined as a combined clinical endpoint of cardiovascular (CV) death, non-fatal myocardial infarction (NF-MI) or re-admission for acute decompensated heart failure (HF), whichever occurred first. Univariate and multivariate analyses were performed and a risk score was computed using the variables which independently predicted the risk of MACE.

Results

During a median follow-up of 5.52 [2.63–7.44] years, 216 first MACE (58 CV deaths, 71 NF-MI and 87 HF) were registered. Mean age was 59.3±12.3 years and most patients (82.8%) were male. Based on the four variables independently associated with MACE, we computed an 8-point risk score: time to reperfusion &gt;4.15h (1 point), GRACE risk score &gt;155 (3 points), CMR-LVEF &lt;40% (3 points), and MVO &gt;1.5 segments (1 point). This score permitted MACE risk stratification: MACE per 100 person-years was 1.96 in the low-risk category (0–2 points), 5.44 in the intermediate-risk category (3–5 points), and 19.7 in the high-risk category (6–8 points): p&lt;0.001 in multivariable Cox survival analysis.

Conclusions

A novel risk score including clinical (time to reperfusion &gt;4.15h and GRACE risk score &gt;155) and CMR (LVEF &lt;40% and MVO &gt;1.5 segments) variables allows for simple and straightforward MACE risk stratification early after STEMI. External validation should confirm the applicability of the risk score.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Instituto de Salud Carlos III and Fondo Europeo de Desarrollo Regional (FEDER) and Sociedad Española de Cardiología.

Impact of persistent MVO late after STEMI on adverse left ventricular remodelling: a CMR study

Background

Despite successful revascularization at the epicardial level, microvascular obstruction (MVO) appears soon after reperfusion in up to 50% of cases. Early MVO has been solidly associated with adverse resulting cardiac structure and heightened risk of future cardiovascular events. Although clinical and experimental studies demostrated the spontaneous repair of MVO, little is known about the occurrence and implications of persistent MVO late after infarction.

Purpose

We used cardiovascular magnetic resonance (CMR) to characterize the impact of persistent MVO late after reperfused ST-segment elevation myocardial infarction (STEMI) on adverse left ventricular (LV) remodelling (ALVR).

Methods

A prospective registry of 471 STEMI patients underwent CMR 7 [5–10] and 198 [167–231] days post infarction, and MVO (&gt;1 segment) and ALVR (relative increase &gt;15% at follow-up CMR) of LV end-diastolic (LVEDVI) and end-systolic volume indices (LVESVI) were determined.

Results

One-week MVO occurred in 209 patients (44%) and persisted in 30 of these (6%). Most patients with persistent MVO (22/30, 73%) displayed extensive (&gt;2.5% of LV mass) MVO at 1 week. Compared with patients without MVO (n=262, 56%) or with MVO only at 1 week (n=179, 38%), those with persistent MVO at follow-up (n=30, 6%) showed higher rates of ALVR-LVEDVI (22%, 27%, 50% p=0.003) and ALVR-LVESVI (20%, 21%, 53% p&lt;0.001). After adjustment, the extent (% of LV mass) of MVO at follow-up was independently associated with ΔLVEDVI (relative increase, %) (p=0.01) and ΔLVESVI (p=0.03). Compared to a 1:1 matched population of 30 patients with MVO only at 1 week, patients with persistent MVO more frequently displayed ALVR-LVEDVI (12% vs. 50%, p=0.003) and ALVR-LVESVI (12% vs. 53%, p=0.001).

Conclusion

MVO persists in a small percentage of patients in chronic phase after STEMI and exerts deleterious effects in terms of LV remodelling. These findings fuel the need for further research on microvascular injury repair.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER” [grant numbers PI20/00637, PI15/00531, FI18/00320, and CIBERCV16/11/00486] and by Conselleria de Educaciόn – Generalitat Valenciana (PROMETEO/2021/008).

Cardiac magnetic resonance predictors of readmission for heart failure in elderly vs not elderly patients after ST-segment elevation myocardial infarction

Background

Patients with ST-segment elevation acute myocardial infarction (STEMI) have an increased risk of re-admission for acute heart failure (AHF). However, identification of patients at higher risk of AHF is challenging, especially in elderly individuals. The implications of cardiac magnetic resonance (CMR) imaging soon after the acute event for this specific purpose are unknown.

Purpose

We aim to study the clinical and CMR predictors of AHF in elderly and not elderly patients after STEMI.

Methods

STEMI patients treated with percutaneous coronary intervention and discharged from three university hospitals were included in a multicenter registry. We registered baseline clinical characteristics, echocardiographic parameters and early (1-week) CMR parameters - left ventricular ejection fraction (LVEF, %), infarct size (% of left ventricular mass) and microvascular obstruction (MVO, number of segments). Univariate and multivariate comparisons were performed in elderly (&gt;70 years) and not elderly (≤70 years) patients to predict AHF during follow-up.

Results

The cohort was comprised of 759 patients, of which 177 (23.3%) were elderly (&gt;70 years). During a mean follow-up of 5.23±3.54 years, 79 (10.4%) patients presented AHF. In not elderly patients, Killip class at admission (HR 2.05 [1.32–3.17], p=0.001), anterior infarction (HR 3.43 [1.13–10.36], p=0.03) and CMR-LVEF (HR 0.94 [0.91–0.98] per increased %, p=0.001) independently predicted AHF. However, a combined risk score comprising these variables was not superior to CMR-LVEF alone to predict AHF during follow-up (AUC 0.81 [0.74–0.88] vs. 0.81 [0.73–0.88], p=NS). In elderly patients, CMR-LVEF was the only predictor of AHF in the final multivariable model (HR 0.94 [0.91–0.97], p&lt;0.001), although its predictive power was moderate (AUC 0.68 [0.56–0.80], p=0.001). Most AHF events in the not elderly subgroup occurred in patients with reduced (≤40%) CMR-LVEF (71%), while in the elderly subgroup AHF occurred more frequently in patients with preserved (≥50%, 30%) or mildly reduced (40–49%, 32%) CMR-LVEF than reduced (≤40%) CMR-LVEF (38%).

Conclusions

LVEF quantified by CMR soon after STEMI can accurately predict the risk of AHF in not elderly (≤70 years) patients and identify those individuals at higher risk (i.e. CMR-LVEF ≤40%). However, in elderly (&gt;70 years) patients most AHF occur in patients with CMR-LVEF &gt;40%, emphasizing the need for better predictive strategies in this population.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Instituto de Salud Carlos III and “Fondos Europeos de Desarrollo Regional FEDER” and Conselleria de Educaciόn – Generalitat Valenciana.

Fourier analysis of collagen bundle orientation in myocardial infarction scars

Collagen bundle orientation (CBO) in myocardial infarct scars plays a major role in scar mechanics and complications after infarction. We aim to compare four histopathological methods for CBO measurement in myocardial scarring. Myocardial infarction was induced in 21 pigs by balloon coronary occlusion. Scar samples were obtained at 4 weeks, stained with Masson’s trichrome, Picrosirius red, and Hematoxylin–Eosin (H&E), and photographed using light, polarized light microscopy, and confocal microscopy, respectively. Masson’s trichrome images were also optimized to remove non-collagenous structures. Two observers measured CBO by means of a semi-automated, Fourier analysis protocol. Interrater reliability and comparability between techniques were studied by the intraclass correlation coefficient (ICC) and Bland–Altman (B&A) plots and limits of agreement. Fourier analysis showed an almost perfect interrater reliability for each technique (ICC ≥ 0.95, p < 0.001 in all cases). CBO showed more randomly oriented values in Masson’s trichrome and worse comparability with other techniques (ICC vs. Picrosirius red: 0.79 [0.47–0.91], p = 0.001; vs. H&E-confocal: 0.70 [0.26–0.88], p = 0.005). However, optimized Masson’s trichrome showed almost perfect agreement with Picrosirius red (ICC 0.84 [0.6–0.94], p < 0.001) and H&E-confocal (ICC 0.81 [0.54–0.92], p < 0.001), as well as these latter techniques between each other (ICC 0.84 [0.60–0.93], p < 0.001). In summary, a semi-automated, Fourier-based method can provide highly reproducible CBO measurements in four different histopathological techniques. Masson’s trichrome tends to provide more randomly oriented CBO index values, probably due to non-specific visualization of non-collagenous structures. However, optimization of Masson’s trichrome microphotographs to remove non-collagenous components provides an almost perfect comparability between this technique, Picrosirius red and H&E-confocal.

Deleterious effect of serum from stemi patients on endothelial cell viability: implication on the resulting cardiac structure

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER” (grant numbers PI20/00637 and CIBERCV16/11/00486) and Conselleria de Educación – Generalitat Valenciana (PROMETEO/2021/008).

Aim

To evaluate the potential deleterious effect of serum from STEMI patients on cardiovascular magnetic resonance (CMR)-derived edema, hemorrhage and microvascular obstruction as well as on the grade of permeability in vitro by promoting endothelial cell apoptosis and necrosis in vitro.

Methods

Human coronary artery endothelial cells (HCAEC) were incubated with serum isolated 24h post-reperfusion from 43 STEMI patients submitted to CMR and from 10 control subjects. Using a multidisciplinary approach on HCAEC, the effect of serum from STEMI patients on the activation of apoptosis and necrosis as well as on changing the permeability and structure of the endothelial monolayer was assessed. The association between the serum-induced apoptosis and necrosis in vitro on HCAEC and CMR-derived edema, hemorrhage, and microvascular obstruction as well as the grade of permeability in vitro was also dissected.

Results

Serum from STEMI patients activated apoptosis (p&lt;0.01) and necrosis (p&lt;0.05) in HCAEC, evaluated by flow cytometry, enzymatic, genetic, and morphological analysis, and also provoked an increased in the permeability of the endothelial monolayer in vitro (p&lt;0.01), due to enlarged intercellular spaces (p&lt;0.05). Those patients whose serum induced higher necrosis in vitro displayed extensive CMR-derived edema (p&lt;0.01), hemorrhage (p&lt;0.01), and microvascular obstruction (p&lt;0.05) as well as more endothelial permeability in vitro (p&lt;0.05).

Conclusions

By activating apoptosis and necrosis on endothelial cells, serum from STEMI patients participates in the appearance of edema, hemorrhage, and microvascular obstruction as well as in increasing endothelium permeability. The negative effect of serum on the endothelial barrier can contribute to the adverse cardiac structure post-STEMI.

Temporal and spatial dynamics in the regulation of myocardial metabolism during the ischemia-reperfusion process

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER” (grant numbers PI20/00637 and CIBERCV16/11/00486) and Conselleria de Educación – Generalitat Valenciana (PROMETEO/2021/008).

Introduction

In the context of severe myocardial ischemia, cardiac metabolism shifts from beta oxidation to glycolisis. However, the temporal and spatial dynamics of the main regulators of myocardial metabolism during the ischemia-reperfusion process in the infarcted heart has not been fully characterized.

Methods

Myocardial infarction (MI) was induced in swine by means of 90 minutes occlusion of the mid left anterior descending coronary artery using angioplasty balloons. Tetrazolium staining and intracoronary infusion of thioflavin-S were used to define the infarcted, adjacent, and remote areas. mRNA and protein expression of PGC1a, PPARa, ERRa, GLUT1, and GLUT4 were quantified in controls and in MI groups submitted to 48 hours and 3 weeks of reperfusion.

Results

Compared to controls, a severe and generalized drop of PGC1a mRNA gene and protein levels occurred in the infarcted, adjacent and remote areas since ischemia onset until 48 hours reperfusion that persists at 1 month in the infarcted region. Similar dynamics occurred in the infarcted, adjacent, and remote areas in the case of PPARa gene expresion; PPARa protein significantly decreased only until 48 hours reperfusion in the infarcted area. ERRa gene and protein expression persistenly decreased only in the infarcted region since ischemia onset until 1 month. Incrases in GLUT1 (since ischemia onset) and GLUT4 (at 1 month) were detected.

Conclusions

Dynamics and generalized changes in metabolism regulation to a shift from beta oxidation to glycolisis occur in the infarcted heart since ischemia onset until late after reperfusion. Further research in this field can be helpful for a better understanding of pathophysiology of myocardial infarction and to explore new therapeutic options.

Implication of caveolae in the pathophysiology of human acute myocardial infarction: a histological study

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work has been funded by “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER” (Exp. PI20/00637) as well as by “Generalitat Valenciana” (Exp. PROMETEO/2021/008).

Introduction

Caveolae are lipid invaginations present in the membrane of most mammalian cells. They are mainly made up of three proteins: caveolin (Cav)-1, 2, and 3 and are involved in signal transduction and ion channels. Since caveolae regulate different signalling pathways to promote cardiac protection, the aim of this study is to compare the expression of Cav-1, 2, and 3 in the human myocardium of control subjects and in patients with myocardial infarction (MI).

Materials

Myocardial samples from human autopsies of 4 controls and 4 MI patients with more than 6 months of evolution were isolated. The infarction and control area were identified by haematoxylin-eosin and Masson’s trichromic stainings. The presence of Cav-1, 2 and 3 was detected by immunochemistry. Afterwards, 5 photographs were taken for each antibody and sample and the presence of each protein was morphometrically quantified using the image analyzer Image-Pro Plus. These results were also corroborated by immunofluorescence.

Results

A constitutive presence of Cav-1, 2, and 3 was observed in the myocardium of control patients, being Cav-1 and 3 higher expressed than Cav-2. Cav-2 and 3 were mainly found in cardiomyocytes, while Cav-1 was detected not only in cardiac muscle cells but also in endothelial cells. Comparing caveolae expression between the peri-infarct region of MI patients and controls, a significant reduction in the expression of the three proteins was observed by immunochemistry. Indeed, the decrease in Cav-2 and 3 could be also detected by immunofluorescence. Lastly, Cav-1 was more expressed in cardiomyocytes than in endothelial cells, but unlike muscle cells, its expression was not diminished after MI.

Conclusions

The presence of caveolin decreases in the myocardial tissue after MI. Further studies are needed to confirm the cardioprotective role of caveolae post-AMI and their use as potential therapeutic target.

Collagen bundle orientation by Fourier analysis in myocardial infarction scarring

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER” and Conselleria de Educación – Generalitat Valenciana.

Introduction

After acute myocardial infarction (AMI), the lack of oxygen and nutrients leads to cardiomyocyte necrosis and eventually to the formation of a collagen-based scar. Infarct scar characteristics, such as collagen bundle orientation, have a relevant influence on scar mechanics, the occurrence of cardiac arrhythmias, left ventricular dilation or aneurysm formation, wall stiffness, and the development of wall rupture or heart failure. However, the most adequate method for collagen bundle orientation (CBO) measurement in myocardial scar is not established.

Purpose

We aim to compare the measurement of collagen bundle orientation in infarct scar by Fourier analysis in three different histopathological techniques.

Methods

Juvenile swine (n=21) were subjected, by means of percutaneous balloon inflation, to a transient 90-min occlusion of mid left anterior descending artery followed by one month of reperfusion (chronic AMI group). Samples were obtained from the infarcted zone and stained with Masson’s trichrome, Picrosirius red and Haematoxylin-Eosin (H-E) standard protocols. Five microphotographs of the myocardial scar were taken at 200x magnification with light, polarised and confocal microscopy, respectively. A single observer measured CBO by means of Fast Fourier Transform analysis using a semi-automated protocol. Comparability between techniques was studied by the Intraclass Correlation Coefficient (ICC), the coefficient of variation (CV) and the Bland-Altman (B&A) plots and limits of agreement.

Results

Measurement of CBO in Masson’s trichrome tended to show higher (more "random-oriented") values than in Picrosirius and H-E+confocal techniques (ICC 0.79 and 0.7, p=0.001 and 0.005; B&A 0.29 to -0.02 and 0.43 to 0.01; CV 6.97% and 12.98%, respectively). However, measurement of CBO in Picrosirius and H-E+confocal techniques showed an "almost perfect" agreement (ICC 0.84, p&lt;0.001; B&A 0.28 to -0.09; CV 17.33%). Selective staining and/or visualization of collagen in these latter techniques may underlie our findings, contrary to non-selective Masson’s trichrome.

Conclusion

Picrosirius red staining (visualized with polarised microscopy) and Haematoxylin-Eosin (visualized with confocal microscopy) are comparable in terms of collagen bundle orientation measurement by Fourier analysis in an animal model of chronic infarct scar. Masson’s trichrome (visualized with light microscopy) tends to show more "random-oriented" values, potentially due to non-specific staining and visualization of non-collagenous structures such as cells, and should not be recommended for this specific purpose.

Exercise ECG Testing and Stress Cardiac Magnetic Resonance for Risk Prediction in Patients With Chronic Coronary Syndrome

PURPOSE

Vasodilator stress cardiac magnetic resonance (VS-CMR) has become crucial in the workup of patients with known or suspected chronic coronary syndrome (CCS). Whether traditional exercise ECG testing (ExECG) contributes prognostic information beyond VS-CMR is unclear.

METHODS

We retrospectively included 288 patients with known or suspected CCS who had undergone ExECG and subsequent VS-CMR in our institution. Clinical, ExECG, and VS-CMR variables were recorded. We defined the serious adverse events (SAE) as a combined endpoint of acute coronary syndrome, admission for heart failure, or all-cause death.

RESULTS

During a mean follow-up of 4.2 ± 2.15 yr, we registered 27 SAE (15 admissions for acute coronary syndrome, eight admissions for heart failure, and four all-cause deaths). Once adjusted for clinical, ExECG, and VS-CMR parameters associated with SAE, the only independent predictors were HRmax in ExECG (HR = 0.98: 95% CI, 0.96-0.99; P = .01) and more extensive stress-induced perfusion defects (PDs, number of segments) in VS-CMR (HR = 1.19: 95% CI, 1.07-1.34; P < .01). Adding HRmax significantly improved the predictive power of the multivariable model for SAE, including PDs (continuous reclassification improvement index: 0.47: 95% CI, 0.10-0.81; P < .05). The annualized SAE rate was 1% (if PD < 2 segments and HRmax > 130 bpm), 2% (if PD < 2 segments and HRmax ≤ 130 bpm), 3.2% (if PD ≥ 2 segments and HRmax > 130 bpm), and 6.3% (if PD ≥ 2 segments and HRmax ≤ 130 bpm), P < .01, for the trend. In patients on β-blocker therapy, however, only PDs in VS-CMR, but not HRmax, predicted SAE.

CONCLUSIONS

We conclude that ExECG contributes significantly to prognostic information beyond VS-CMR in patients with known or suspected CCS.

Risk score for early risk prediction by cardiac magnetic resonance after acute myocardial infarction

BACKGROUND

Cardiac magnetic resonance (CMR) performed early after ST-segment elevation myocardial infarction (STEMI) can improve major adverse cardiac event (MACE) risk prediction. We aimed to create a simple clinical-CMR risk score for early MACE risk stratification in STEMI patients.

METHODS

We performed a multicenter prospective registry of reperfused STEMI patients (n = 1118) in whom early (1-week) CMR-derived left ventricular ejection fraction (LVEF), infarct size and microvascular obstruction (MVO) were quantified. MACE was defined as a combined clinical endpoint of cardiovascular (CV) death, non-fatal myocardial infarction (NF-MI) or re-admission for acute decompensated heart failure (HF).

RESULTS

During a median follow-up of 5.52 [2.63-7.44] years, 216 first MACE (58 CV deaths, 71 NF-MI and 87 HF) were registered. Mean age was 59.3 ± 12.3 years and most patients (82.8%) were male. Based on the four variables independently associated with MACE, we computed an 8-point risk score: time to reperfusion >4.15 h (1 point), GRACE risk score > 155 (3 points), CMR-LVEF <40% (3 points), and MVO >1.5 segments (1 point). This score permitted MACE risk stratification: MACE per 100 person-years was 1.96 in the low-risk category (0-2 points), 5.44 in the intermediate-risk category (3-5 points), and 19.7 in the high-risk category (6-8 points): p < 0.001 in multivariable Cox survival analysis.

CONCLUSIONS

A novel risk score including clinical (time to reperfusion >4.15 h and GRACE risk score > 155) and CMR (LVEF <40% and MVO >1.5 segments) variables allows for simple and straightforward MACE risk stratification early after STEMI. External validation should confirm the applicability of the risk score.

Combined assessment of stress cardiovascular magnetic resonance and angiography to predict the effect of revascularization in chronic coronary syndrome patients

AIMS

The role of revascularization in chronic coronary syndrome (CCS) and the value of ischaemia vs. anatomy to guide decision-making are in constant debate. We explored the potential of a combined assessment of ischaemic burden by vasodilator stress cardiovascular magnetic resonance (CMR) and presence of multivessel disease by angiography to predict the effect of revascularization on all-cause mortality in CCS.

METHODS AND RESULTS

The study group comprised 1066 CCS patients submitted to vasodilator stress CMR pre-cardiac catheterization (mean age 66 ± 11 years, 69% male). Stress CMR-derived ischaemic burden (extensive if >5 ischaemic segments) and presence of multivessel disease in angiography (two- or three-vessel or left main stem disease) were computed. The influence of revascularization on all-cause mortality was explored and adjusted hazard ratios (HRs) with the corresponding 95% confidence intervals were obtained. During a median 7.51-year follow-up, 557 (52%) CMR-related revascularizations and 308 (29%) deaths were documented. Revascularization exerted a neutral effect on all-cause mortality in the whole study group [HR 0.94 (0.74-1.19), P = 0.6], in patients without multivessel disease [n = 598, 56%, HR 1.12 (0.77-1.62), P = 0.6], and in those with multivessel disease without extensive ischaemic burden [n = 181, 17%, HR 1.66 (0.91-3.04), P = 0.1]. However, compared to non-revascularized patients, revascularization significantly reduced all-cause mortality in patients with simultaneous multivessel disease and extensive ischaemic burden (n = 287, 27%): 3.77 vs. 7.37 deaths per 100 person-years, HR 0.60 (0.40-0.90), P = 0.01.

CONCLUSIONS

In patients with CCS submitted to catheterization, evidence of simultaneous extensive CMR-related ischaemic burden and multivessel disease identifies the subset in whom revascularization can reduce all-cause mortality.

Overexpression of genes involved in lymphocyte activation and regulation are associated with reduced CRM-derived cardiac remodelling after STEMI

Aims

Lymphopenia after ST-segment elevation myocardial infarction (STEMI) correlates with deleterious cardiac consequences and worse prognosis. An in-depth examination of genes implicated in lymphocyte proliferation, activation and regulation and their association with short- and long-term cardiac structure and function is therefore of great interest.

Methods

Peripheral blood mononuclear cells were isolated from 10 control subjects and 64 patients with a first STEMI treated with primary percutaneous coronary intervention and submitted to cardiac magnetic resonance after 1 week and 6 months. mRNA expression of genes implicated in lymphocyte activation (CD25 and CD69) and regulation [programmed death (PD)-1 and cytotoxic T-lymphocyte antigen (CTLA)-4] were determined by qRT-PCR.

Results

In comparison to controls, STEMI patients showed heightened mRNA expression of CD25 and lower PD-1 and CTLA-4 96h after coronary reperfusion. Patients with extensive infarctions (&gt;30% of left ventricular mass) at 1 week displayed a notable reduction in CD25, CD69, PD-1, and CTLA-4 expression (p&lt;0.05). However, CD25 was the only predictor of 1-week extensive infarct size in multivariate logistic regression analysis (odds ratio 0.019; 95% confidence interval [0.001–0.505]; p=0.018). Regarding long-term ventricular function, mRNA expression of CD25 under the mean value was associated with worse ventricular function and more adverse remodelling.

Conclusions

Following STEMI, heightened expression of genes expressed in regulatory T cells (CD25 and CD69) and immune checkpoints (PD-1 and CTLA-4) correlates with a better short- and long-term cardiac structure and function. Advancing understanding of the pathophysiology of lymphopenia and evaluating novel immunomodulatory therapies will help translate these results into future clinical trials.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER”

Sex differences in mortality in stable patients undergoing vasodilator stress cardiovascular magnetic resonance

Introduction

The prognostic value and therapeutic implications of ischemia as derived from vasodilator stress cardiovascular magnetic resonance (CMR) could differ in men and women, but it has not been stablished.

Purpose

We assessed the influence of the ischemic burden as derived from CMR on the risk of death and the effect of revascularization across sex.

Methods

We evaluated 6,237 consecutive patients with known or suspected chronic coronary syndrome (CCS). Extensive ischemia was defined as &gt;5 segments with perfusion deficit. Multivariate Cox proportional hazard regression models were used.

Results

A total of 2,371 (38.0%) patients were women and 583 (9.3%) underwent CMR-related revascularization. During a median follow-up of 5.13 years, 687 (11.0%) deaths were reported. We found an adjusted differential effect of CMR-derived ischemic burden across sex (p-value for interaction=0.039). Women exhibited an adjusted lower risk of death along most of the continuous ischemic burden but equalled men's risk when extensive ischemia was present. Likewise, CMR-related revascularization was shown to be differentially associated with the risk of mortality across sex (p-value for interaction=0.025). In patients with non-extensive ischemia, revascularization was related to a higher risk of death, with a greater extent in women. At higher ischemic burden, revascularization was associated with a lower risk in men, with more uncertain results in women.

Conclusions

CMR-derived ischemic burden allows predicting the risk of death and gives insight into the potential effect of revascularization in men and women with CCS. Compared to men, women with nonextensive ischemia displayed a lower risk and a similar risk with a higher ischemic burden. The impact of CMR-related revascularization on mortality risk was also significantly different according to ischemic burden and sex.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This study was supported by the Instituto de Salud Carlos III and cofunded by the European Regional Development Fund (ERDF).

Sex differences on new-onset heart failure in patients with known or suspected chronic coronary syndrome

Background

The impact of sex in patients with chronic coronary syndrome (CCS) has been widely reported, but little is known about the influence of sex on the risk of new-onset HF in patients with CCS.

Objectives

We aimed to examine sex-related differences and new-onset heart failure (HF) risk in patients with known or suspected CCS undergoing vasodilator stress cardiac magnetic resonance (CMR).

Methods

We prospectively evaluated 5,899 consecutive HF-free patients submitted to stress CMR for known or suspected CCS. Ischemic burden (number of segments with stress-induced perfusion deficit) and left ventricular ejection fraction (LVEF) were assessed by CMR. The association between sex and new-onset HF (including outpatient diagnosis or acute HF hospitalization) was evaluated using a Cox proportional-hazards regression model adjusted for competing events (death, myocardial infarction, and non-CMR-related revascularization).

Results

A total of 2,289 (38.8%) patients were women, and 539 (9.1%) underwent CMR-related revascularization. During a median follow-up of 4.5 years, 610 (10.3%) patients died, 191 (3.2%) suffered a myocardial infarction, 420 (7.1%) underwent CMR-non-related revascularization, and 314 (5.3%) developed new-onset HF. Unadjusted new-onset HF rates were higher in women than in men (1.25 vs 0.83 per 100 person/years, p=0.002) (Figure 1). After comprehensive multivariate adjustment, women showed an increased risk of new-onset HF (HR=1.61, 95% CI: 1.21–2.13, p=0.001). Compared with men, the risk of new-onset HF was higher in women with LVEF &gt;53%.

Conclusions

Compared with men, women with CCS are at a higher risk of new-onset HF. Further studies are needed to unravel the mechanisms behind these sex-related differences.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Instituto de Salud Carlos III and Fondo Europeo de Desarrollo Regional (FEDER) Figure 1

Downstream testing after exercise ECG stress test – can we predict ischemia on subsequent vasodilator stress cardiac magnetic resonance?

Background

Exercise ECG stress test (ExECG) is useful in the diagnostic work-up of patients with chest pain and known or suspected stable ischemic heart disease (SIHD). However, current guidelines recommend a stress imaging, ischemia-detecting technique such as vasodilator stress cardiac magnetic resonance (vs-CMR) if available. Whether clinical and ExECG variables can predict ischemia on subsequent vs-CMR testing is unknown.

Material and methods

We retrospectively included 289 patients who underwent an ExECG and a subsequent vs-CMR in the year after this test and who didn't undergo a revascularization procedure in this time frame. Clinical, ExECG and vs-CMR variables were included in the registry. vs-CMR was considered positive if ischemia was evident in at least one myocardial segment on stress first-pass perfusion without concomitant necrosis on late gadolinium enhancement imaging. We performed univariate and multivariate analysis to check for the association of variables with the risk of ischemia on vs-CMR.

Results

Mean time from ExECG to vs-CMR was 97,27±88,31 days and 91 vs-CMR were positive for ischemia. Age, male sex, diabetes mellitus, hypertension, dyslipidaemia and personal history of ischemic heart disease, percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) were predictors of ischemia on vs-CMR in the univariate analysis. On ExECG, time of exercise, exercise capacity, chest pain during ExECG, maximum heart rate (HR) and systolic blood pressure (SBP), % of predicted HR, chronotropic reserve index, maximum and reserve of double product and Duke Treadmill Score were also associated with ischemia on vs-CMR. However, the only independent predictors on multivariate binary logistic regression stepwise analysis were history of PCI (HR 3.79 [2.03–7.09], p&lt;0.001) or CABG (HR 5.57 [1.80–17.26], p=0.003), maximum double product (HR 0.94 [0.90–0.99] per 1000 increase, p=0.02) and Duke Treadmill Score (HR 0.95 [0.91–0.99], p=0.019). Subgroup analysis showed that male sex (HR 1.95 [1.16–3.28], p=0.012), history of ischemic heart disease (HR 4.73 [2.88–7.76], p&lt;0.001) and maximum double product (HR 0.94 [0.90–0.98] per 1000 increase, p=0.006) were predictors of ischemia on vs-CMR in non-revascularized patients (n=212). In revascularized patients (n=77) the only independent predictor was the Duke Treadmill Score on ExECG (HR 0.93 [0.86–0.99], p=0.048).

Conclusions

Several ExECG variables, namely Duke Treadmill Score and parameters of myocardial oxygen consumption such as maximum doble product, can predict the risk of ischemia on subsequent vs-CMR in revascularized and non-revascularized patients with chest pain. This can help select patients who should undergo vs-CMR afeter ExECG for ischemia detection.

Funding Acknowledgement

Type of funding sources: None.

Exercise ECG testing in patients without known ischemic heart disease: predictors of ischemia of downstream vasodilator stress cardiac magnetic resonance

Background

In routine clinical practice, patients with chest pain and suspected stable ischemic heart disease (SIHD) usually undergo an exercise ECG stress test (ExECG) for ischemia detection. However, since the sensitivity of this technique is relatively low, concerns exist that many patients could remain underdiagnosed. We intend to assess the clinical and ExECG predictors of ischemia on subsequent vasodilator stress cardiac magnetic resonance (vs-CMR) to help select which patients should undergo downstream testing after an initial ExECG.

Material and methods

We retrospectively included 197 patients without previous history of ischemic heart disease who underwent an ExECG and a subsequent vs-CMR in the year after this test and who didn't undergo a revascularization procedure in this time frame. Clinical, ExECG and vs-CMR variables were included in the registry. vs-CMR was considered positive if ischemia was evident in at least one myocardial segment on stress first-pass perfusion without concomitant necrosis on late gadolinium enhancement imaging. We performed univariate and multivariate analysis to check for the association of variables with the risk of ischemia on vs-CMR.

Results

Mean time from ExECG to vs-CMR was 88.69±84.32 days and 37 vs-CMR were positive for ischemia. Male sex, less exercise time, less % of maximum predicted exercise capacity, less maximum double product (heart rate x systolic blood pressure) and less double product reserve (DPR = maximum double product - basal double product) were associated with ischemia on vs-CMR on univariate analyses. However, the only independent predictors of ischemia on vs-CMR on multivariate binary logistic regression were male sex (HR 2.62 [CI 95%: 1.13–5.76], p=0.016) and less DPR (HR 0.90 [CI 95%: 0.84–0.97] per 1000 increase, p=0.006). The risk score derived from these two variables had a moderate predictive power (ROC curves, AUC 0.657, p=0.003). The best cut-off point for the DPR was 12400, as derived from the Youden index. It allowed stratification of the risk of ischemia on vs-CMR, which ranged from 9% in women with &gt;12400 DPR, 18.8% in men with &gt;12400 DPR, 24.1% in women with ≤12400 DPR to 42.9% in men with ≤12400 DPR (p=0.005, Figure 1).

Conclusions

Male sex and less double product reserve on ExECG can moderately predict the risk of ischemia on subsequent vs-CMR in patients presenting with chest pain and without previous SIHD. This can help select patients who benefit most from vs-CMR for diagnostic purposes.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Residual ST-segment elevation at pre-discharge ECG after STEMI: association with long-term prognosis and structural consequences at 6-month CMR

Introduction

Residual ST-segment elevation after ST-segment elevation myocardial infarction (STEMI) has been traditionally interpreted as a predictor of left ventricular dysfunction and ventricular aneurism. More recently, it has also been associated with more severe structural consequences in cardiac magnetic resonance (CMR) performed soon after STEMI. However, the implications in terms of long-term prognosis of patients and structural consequences in CMR performed late after STEMI are unclear.

Methods

Data was obtained from a prospective registry of reperfused STEMI patients. At pre-discharge ECG, sum and maximum ST-segment elevation (mm), ST-segment resolution (%) and the number of Q-leads with residual ST-segment elevation &gt;1 mm (Q-STE) were assessed. 6-month CMR parameters were quantified: left ventricular ejection fraction (LVEF, %), left ventricular end-diastolic and end-systolic volume indexes (LVEDVI and LVESVI, mL/m2), infarct size (IS, % left ventricular mass) and microvascular obstruction (MVO, % left ventricular mass). The primary end-point was major adverse cardiac events (MACE), defined as all-cause death and/or re-admission for acute heart failure, whichever occurred first.

Results

488 patients were included. Mean age was 58±12 years, 80.3% were males and smoking was the most prevalent cardiovascular risk factor. During a 7-year mean and median follow-up, 92 MACE were registered (19%), 39 all-cause deaths and 53 re-admission for acute heart failure. Q-STE &gt;1 lead was detected in 172 patients (35%) and it was the most potent ECG predictor of MACE (26% vs 15%, p=0.002). Q-STE was also associated with structural changes at 6-month CMR: larger LVEDVI (87,39±27,47 mL/m2 vs 74,31±24,13 mL/m2) and LVESVI (45,45±25,24 mL/m2 vs 32,53±20,85 mL/m2), less LVEF (50,48±13,95% vs 58,75±12,3%) and larger infarct size (24,91±11,6% vs 14,38±11,41%) (p&lt;0.001 for all comparisons, Figure 1). After adjustment for baseline and ECG characteristics, Q-STE (per lead with &gt;1 mm) was independently associated with a higher risk of long-term MACE (HR 1.24 [CI 95%: 1.09–1.40], p=0.001), depressed (&lt;40%) LVEF (HR 1.26 [CI 95%: 1.02–1.56], p=0.03) and large (&gt;30% left ventricular mass) infarct size (HR 1.34 [CI 95%: 1.08–1.67], p=0.008) at 6-month CMR. Survival free from MACE was lower in patients with &gt;1 lead Q-STE (log-rank=9.07, p=0.003) (Figure 2).

Conclusions

Residual ST-segment elevation after STEMI represents a widely available predictor of adverse long-term prognosis and late CMR-derived left ventricular remodelling. It could contribute to select patients who would benefit of close monitoring.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Fondos Europeos de Desarrollo Regional FEDERInstituto de Salud Carlos III Figure 1. Structural changes at 6-month CMRFigure 2. Survival free from MACE

Prognostic value of baseline versus 6-month follow infarct size in patients with reperfused STEMI

Background

Acute infarct size is a predictor of clinical outcomes in acute ST segment elevation myocardial infarction (STEMI) patients, although its prognostic value has differed between studies. In acute STEMI, infarct size is often overestimated due to the presence of extensive myocardial oedema, a confounder that is no longer present at a 6-month follow-up study. It was our purpose to assess whether infarct size in the acute phase or at 6-months follow-up provided superior prognostic information in STEMI patients.

Methods

STEMI patients who underwent successful primary percutaneous revascularization were included and a cardiac magnetic resonance (CMR) was performed between 5–7 days after STEMI and at 6 months to study infarct size (as a % of myocardial mass). The primary endpoint was a composite of cardiovascular mortality, hospitalization for heart failure and ventricular arrhythmia.

Results

A total of 796 patients were included (mean age 58.3±11.5 years, 82.4% male, 52.3% anterior infarction). During a mean follow-up of 59 months, 59 patients (7.4%) presented with the primary end-point (cardiovascular death n=7, hospitalization for heart failure n=52, ventricular arrhythmia n=1). ROC curve analysis (figure 1) showed a non-significant difference between baseline and 6-month infarct size for the prediction of the primary endpoint (baseline AUC 0.685 95% CI 0.610–0.760, 6-month AUC 0.713 95% CI 0.643–0.782, p=0.60). Optimal cut-off values for baseline and 6-months follow-up infarct size for prediction of outcomes, respectively 22% and 17.5%, were used for Kaplan-Meier curve analysis (figure 2).

Conclusion

Infarct size estimated during the first week after STEMI and at 6-months follow-up showed similar predictive value and with similar cut-off values. Therefore, the prognostic information provided by infarct size can be obtained during initial STEMI admission and does not require a waiting period for infarct size stabilization.

Funding Acknowledgement

Type of funding sources: None. ROC curve analysisKaplan-Meier analysis

Stress cardiovascular magnetic resonance and mortality in a registry of 2496 elderly patients with chronic coronary syndrome. Prognosis and decision-making

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Instituto de Salud Carlos III, Fondo Europeo de Desarrollo Regional (FEDER)

Introduction and objectives. Management of the elderly with chronic coronary syndrome (CCS) is challenging. We explore the prognostic value and the usefulness for decision-making of the ischemic burden determined by vasodilator stress cardiac magnetic resonance (CMR) imaging in elderly patients with known or suspected CCS.

Methods. The study group was made up of 2496 patients older than 70 years submitted to vasodilator stress CMR for known or suspected CCS. The ischemic burden (number of segments with stress-induced perfusion deficit) was calculated following the 17-segment model. Its association with all-cause mortality and the effect of CMR-guided revascularization were analyzed retrospectively.

Results. During a median follow-up of 4.58 years, 430 deaths (17.2%) were recorded. A larger ischemic burden was an independent predictor of mortality: hazard ratio [95% confidence intervals]: 1.04 [1.01-1.07] for each additional ischemic segment, p = 0.006). This association also occurred in patients over 80 years of age and in women (p &lt; 0.001). Compared to non-revascularized patients, revascularization associated with worse outcomes at low ischemic burden and exerted protective prognostic effect in patients with extensive ischemia both in the whole group (p for interaction = 0.003) and in 496 patients matched 1:1 by a propensity score (p = 0.06).

Conclusions. Vasodilator stress CMR represents a valuable tool to stratify risk in elderly patients with CCS and might be helpful to guide decision-making in this scenario.

Sequential cardiovascular magnetic resonance assessment of left ventricular ejection fraction for prediction of subsequent events in a large multicenter STEMI registry

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This work was supported by “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER”

Background. Cardiovascular magnetic resonance (CMR) is the best tool for left ventricular ejection fraction (LVEF) quantification, but as yet the prognostic value of sequential LVEF assessment for major adverse cardiac event (MACE) prediction after ST-segment elevation myocardial infarction (STEMI) is uncertain.

Purpose. We explored the prognostic impact of sequential assessment of CMR-derived LVEF after STEMI to predict subsequent MACE.

Methods. We recruited 1036 STEMI patients in a large multicenter registry. LVEF (reduced [r]: &lt;40%; mid-range [mr]: 40-49%; preserved [p]: ≥50%) was sequentially quantified by CMR at 1 week and after &gt;3 months of follow-up. MACE was regarded as cardiovascular death or re-admission for acute heart failure after follow-up CMR.

Results. During a 5.7-year mean follow-up, 82 MACE (8%) were registered. The MACE rate was higher only in patients with LVEF &lt; 40% at follow-up CMR (r-LVEF 22%, mr-LVEF 7%, p-LVEF 6%; p-value &lt; 0.001). Based on LVEF dynamics from 1-week to follow-up CMR, incidence of MACE was 5% for sustained LVEF³40% (n = 783), 13% for improved LVEF (from &lt;40 to ³40%, n = 96), 21% for worsened LVEF (from ³40% to &lt;40%, n = 34) and 22% for sustained LVEF &lt;40% (n = 100), p-value &lt; 0.001. Using a Markov approach that considered all studies performed, transitions towards improved LVEF predominated and only r-LVEF (at any time assessed) was significantly related to higher incidence of subsequent MACE.

Conclusions. LVEF constitutes a pivotal CMR index for simple and dynamic post-STEMI risk stratification. Detection of reduced LVEF (&lt;40%) by CMR at any time during follow-up identifies a small subset of patients at high risk of subsequent events.

EpCAM and microvascular obstruction in patients with STEMI: a cardiac magnetic resonance study

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This study was funded by “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER”

Bachground. Microvascular obstruction (MVO) is negatively associated with cardiac structure and worse prognosis after ST-segment elevation myocardial infarction (STEMI). Epithelial cell adhesion molecule (EpCAM), involved in endothelium adhesion, is an understudied area in the MVO setting.

Purpose. We aimed to evaluate whether EpCAM is associated with the appearance of cardiac magnetic resonance (CMR)-derived MVO and long-term systolic function in reperfused STEMI.

Methods. We prospectively included 106 patients with a first STEMI treated with primary percutaneous coronary intervention, quantifying serum levels of EpCAM 24 hours post-reperfusion. All patients underwent CMR imaging 1 week and 6 months post-STEMI. The independent correlation of EpCAM with MVO, systolic volume indices, and left ventricular ejection fraction (LVEF) was evaluated.

Results. The mean age of the sample was 59 ± 13 years and 76% were male. Patients were dichotomized according to EpCAM median (4.48 pg/mL). At 1-week CMR, lower EpCAM was related to extensive MVO (p-value = 0.02) and greater infarct size (p-value = 0.02). At presentation, only EpCAM values were significantly associated with the presence of MVO in univariate (Odds Ratio [95% confidence interval] (OR [95% CI]): 0.58 [0.38-0.88], p-value = 0.01) and multivariate logistic regression models (OR [95% CI]: 0.54 [0.34-0.85], p-value = 0.007). Although MVO tends to resolve at chronic phases, decreased EpCAM was associated with worse systolic function: depressed LVEF (p-value = 0.009) and higher left ventricular end-systolic volume (p-value = 0.04).

Conclusions. EpCAM is associated with occurrence of CMR-derived MVO at acute phases and long-term adverse ventricular remodeling post-STEMI. Future studies are needed to confirm EpCAM as biomarker, and eventually biotarget in STEMI pathophysiology.

Magnetic Resonance Assessment of Left Ventricular Ejection Fraction at Any Time Post-Infarction for Prediction of Subsequent Events in a Large Multicenter STEMI Registry

BACKGROUND

Magnetic resonance imaging (MRI) is the most accurate imaging technique for left ventricular ejection fraction (LVEF) quantification, but as yet the prognostic value of LVEF assessment at any time after ST-segment elevation myocardial infarction (STEMI) for subsequent major adverse cardiac event (MACE) prediction is uncertain.

PURPOSE

To explore the prognostic impact of MRI-derived LVEF at any time post-STEMI to predict subsequent MACE (cardiovascular death or re-admission for acute heart failure).

STUDY TYPE

Prospective.

POPULATION

One thousand thirteen STEMI patients were included in a multicenter registry.

FIELD STRENGTH/SEQUENCE

1.5-T. Balanced steady-state free precession (cine imaging) and segmented inversion recovery steady-state free precession (late gadolinium enhancement) sequences.

ASSESSMENT

Post-infarction MRI-derived LVEF (reduced [r]: <40%; mid-range [mr]: 40%-49%; preserved [p]: ≥50%) was sequentially quantified at 1 week and after >3 months of follow-up.

STATISTICAL TESTS

Multi-state Markov model to determine the prognostic value of each LVEF state (r-, mr- or p-) at any time point assessed to predict subsequent MACE. A P-value <0.05 was considered to be statistically significant.

RESULTS

During a 6.2-year median follow-up, 105 MACE (10%) were registered. Transitions toward improved LVEF predominated and only r-LVEF (at any time assessed) was significantly related to a higher incidence of subsequent MACE. The observed transitions from r-LVEF, mr-LVEF, and p-LVEF states to MACE were: 15.3%, 6%, and 6.7%, respectively. Regarding the adjusted transition intensity ratios, patients in r-LVEF state were 4.52-fold more likely than those in mr-LVEF state and 5.01-fold more likely than those in p-LVEF state to move to MACE state. Nevertheless, no significant differences were found in transitions from mr-LVEF and p-LVEF states to MACE state (P-value = 0.6).

DATA CONCLUSION

LVEF is an important MRI index for simple and dynamic post-STEMI risk stratification. Detection of r-LVEF by MRI at any time during follow-up identifies a subset of patients at high risk of subsequent events.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 2.

Ischemia-reperfusion injury to coronary arteries: Comprehensive microscopic study after reperfused myocardial infarction

BACKGROUND

Coronary arteries supply oxygen and nutrients to the heart. We evaluated the dynamics of microscopic damage throughout the ischemia-reperfusion process in the wall of coronary arteries following myocardial infarction (MI).

METHODS

In a swine model of reperfused MI, animals were divided into one control and four MI groups: 90-min ischemia without reperfusion, or followed by one minute, one week or one month reperfusion. Left anterior descending (LAD; infarct-related artery) and control right coronary arteries (RCA) were isolated. Taking the balloon inflation region as a reference, we isolated the proximal and distal LAD areas, performing histological staining and immunohistochemistry.

RESULTS

Although mild changes in tunica intima were observed during ischemia, an almost complete absence of endothelium, and abnormal breaks in the internal elastic layer were found post-revascularization. In tunica media, increased thickness was observed soon after reperfusion, whereas larger thickness, disorganized muscle cell distribution and edema were found one week after reperfusion. This damage was more pronounced in distal rather than proximal LAD, whereas no changes were detected in RCA. In the tunica adventitia, vasa vasorum density decayed during ischemia in both LAD regions, but was restored after one month. Leukocyte adhesion to the artery was observed post-revascularization, developing into a massive presence in the three layers one week post-reperfusion.

CONCLUSIONS

Ischemia-reperfusion can itself induce damage in the wall of the epicardial coronary artery, becoming more pronounced in the region distal to balloon inflation. Exploring these abnormalities will provide insight into the pathophysiology of coronary circulation and MI.

Sex differences in mortality in stable patients undergoing vasodilator stress cardiovascular magnetic resonance

OBJECTIVE

We assessed the influence of the ischaemic burden (IB) as derived from vasodilator stress cardiovascular magnetic resonance (CMR) on the risk of death and the effect of revascularisation across sex.

METHODS

We evaluated 6237 consecutive patients with known or suspected chronic coronary syndrome (CCS). Extensive ischaemia was defined as >5 segments with perfusion deficit. Multivariate Cox proportional hazard regression models were used.

RESULTS

A total of 2371 (38.0%) patients were women and 583 (9.3%) underwent CMR-related revascularisation. During a median follow-up of 5.13 years, 687 (11.0%) deaths were reported. We found an adjusted differential effect of CMR-derived IB across sex (p value for interaction=0.039). Women exhibited an adjusted lower risk of death and only equaled men's risk when extensive ischaemia was present. Likewise, CMR-related revascularisation was shown to be differentially associated with the risk of mortality across sex (p value for interaction=0.025). In patients with non-extensive ischaemia, revascularisation was associated with a higher risk of death, with a greater extent in women. At higher IB, revascularisation was associated with a lower risk in men, with more uncertain results in women.

CONCLUSIONS

CMR-derived IB allows predicting the risk of death and gives insight into the potential effect of revascularisation in men and women with CCS. Compared with men, women with non-extensive ischaemia displayed a lower risk and a similar risk with a higher IB. The impact of CMR-related revascularisation on mortality risk was also significantly different according to IB and sex. Further research will be needed to confirm these hypothesis-generating findings.

Stress cardiovascular magnetic resonance and mortality in a registry of 2496 elderly patients with chronic coronary syndrome. Prognosis and decision-making

Funding Acknowledgements

Type of funding sources: None.

Background. In recent guidelines, non-invasive imaging techniques play a pivotal role in the management of chronic coronary syndrome (CCS). The elderly represent a large percentage of our routine CCS population and risk stratification in this scenario is challenging. The potential of vasodilator stress cardiovascular magnetic resonance (CMR) for this purpose is unknown.

Purpose. We explore the prognostic value and the usefulness for decision-making of the ischemic burden determined by vasodilator stress CMR imaging in a large cohort of elderly patients with known or suspected CCS.

Methods. The study group was made up of 2496 patients older than 70 years submitted to vasodilator stress CMR for known or suspected CCS in our health department from 2001 to 2016 (mean age 76 ± 4 years, 52% male). Clinical and vasodilator stress CMR characteristics were prospectively recorded. The ischemic burden (number of segments with stress-induced perfusion deficit) was calculated following the 17-segment model. Its association with all-cause mortality and the effect of vasodilator stress CMR-guided revascularization (within the following 3 months) were analyzed retrospectively.

Results. During a median follow-up of 4.58 years, 430 deaths (17.2%) were recorded. A larger ischemic burden was an independent predictor of mortality: hazard ratio [95% confidence intervals]: 1.04 [1.01-1.07] for each additional ischemic segment, p = 0.006). This association also occurred in patients over 80 years of age and in women (p &lt; 0.001). Compared to non-revascularized patients, revascularization associated with worse outcomes at low ischemic burden and exerted protective prognostic effect in patients with extensive ischemia both in the whole group (p for interaction = 0.003) and in 496 patients matched 1:1 by a propensity score (p = 0.06).

Conclusions. Vasodilator stress CMR represents a valuable tool to stratify risk in elderly patients with known or suspected CCS and might be helpful to guide decision-making in this scenario.

Abstract Figure 1

Sex differences on new-onset heart failure in patients with known or suspected coronary artery disease

AIMS

The impact of sex in patients with CAD has been widely reported, but little is known about the influence of sex on the risk of new-onset HF in patients with known or suspected CAD. We aimed to examine sex-related differences and new-onset heart failure (HF) risk in patients with known or suspected coronary artery disease (CAD) undergoing vasodilator stress cardiac magnetic resonance (CMR).

METHODS AND RESULTS

We prospectively evaluated 5899 consecutive HF-free patients submitted to stress CMR for known or suspected CAD. Ischaemic burden (number of segments with stress-induced perfusion deficit) and left ventricular ejection fraction (LVEF) were assessed by CMR. The association between sex and new-onset HF (including outpatient diagnosis or acute HF hospitalization) was evaluated using a Cox proportional hazards regression model adjusted for competing events [death, myocardial infarction (MI), and revascularization]. A total of 2289 (38.8%) patients were women. During a median follow-up of 4.5 years, 610 (10.3%) patients died, 191 (3.2%) suffered an MI, 905 (15.3%) underwent revascularization, and 314 (5.3%) developed new-onset HF. Unadjusted new-onset HF rates were higher in women than in men (1.25 vs. 0.83 per 100 person-years, P = 0.001). After comprehensive multivariate adjustment, women showed an increased risk of new-onset HF (hazard ratio 1.58, 95% confidence interval 1.18-2.10; P = 0.002). We found a sex-differential effect along the continuum of LVEF (P-value for interaction = 0.007). At lower LVEF, there was an increased risk in both sexes. However, compared with men, the risk of new-onset HF was higher in women with LVEF >55%.

CONCLUSION

Women with known or suspected CAD are at a higher risk of new-onset HF. Further studies are needed to unravel the mechanisms behind these sex-related differences.

Long-term prognostic implications of revascularization in patients with known or suspected chronic coronary syndromes without ischemia in vasodilator stress cardiovascular magnetic resonance

AIMS

In this study, we evaluated the association between symptoms-guided revascularization occurred within three months following a negative vasodilator stress cardiovascular magnetic resonance (negative stress-CMR) and long-term adverse events in patients with known or suspected chronic coronary syndrome (CCS).

METHODS

We retrospectively evaluated 3517 patients in which the stress first-pass perfusion imaging revealed no ischemia. The primary endpoint was the composite of death, spontaneous myocardial infarction, heart failure (HF), or stroke. The association between symptoms-guided revascularization after a negative stress-CMR and the endpoint was assessed using the multivariable Cox proportional hazard regression model.

RESULTS

The mean age was 64.7 ± 11.9 years and 45.4% were females. Coronary angiography and revascularization following a negative stress-CMR were performed in 176 (5%) and 59 (1.7%) patients. At a median follow-up of 4.8 years (2.0-8.2), 529 (15%) patients experienced the primary endpoint (2.0 per 100 person-years). Revascularization following a negative CMR was associated with a higher incidence of the composite (4.85 vs. 1.96 per 100 person-years, p < 0.001) and each of the isolated components of the endpoint, except for the HF endpoint, in which differences were borderline significant. After multivariate adjustment, revascularization remained associated with an excess of risk (HR = 2.01, 95% CI:1.21-3.30; p = 0.007).

CONCLUSIONS

In CCS patients with persistent symptoms but without evidence of ischemia in vasodilator stress CMR, revascularization was associated with a higher risk of adverse clinical events.

Overexpression of genes involved in lymphocyte activation and regulation are associated with reduced CRM-derived cardiac remodelling after STEMI

AIMS

Lymphopenia after ST-segment elevation myocardial infarction (STEMI) correlates with deleterious cardiac consequences and worse prognosis. An in-depth examination of genes implicated in lymphocyte proliferation, activation and regulation and their association with short- and long-term cardiac structure and function is therefore of great interest.

METHODS

Peripheral blood mononuclear cells were isolated from 10 control subjects and 64 patients with a first STEMI treated with primary percutaneous coronary intervention and submitted to cardiac magnetic resonance after 1 week and 6 months. mRNA expression of genes implicated in lymphocyte activation (CD25 and CD69) and regulation [programmed death (PD)-1 and cytotoxic T-lymphocyte antigen (CTLA)-4] were determined by qRT-PCR.

RESULTS

In comparison to controls, STEMI patients showed heightened mRNA expression of CD25 and lower PD-1 and CTLA-4 96 h after coronary reperfusion. Patients with extensive infarctions (>30% of left ventricular mass) at 1 week displayed a notable reduction in CD25, CD69, PD-1, and CTLA-4 expression (p < 0.05). However, CD25 was the only predictor of 1-week extensive infarct size in multivariate logistic regression analysis (odds ratio 0.019; 95% confidence interval [0.001-0.505]; p = 0.018). Regarding long-term ventricular function, mRNA expression of CD25 under the mean value was associated with worse ventricular function and more adverse remodelling.

CONCLUSIONS

Following STEMI, heightened expression of genes expressed in regulatory T cells (CD25 and CD69) and immune checkpoints (PD-1 and CTLA-4) correlates with a better short- and long-term cardiac structure and function. Advancing understanding of the pathophysiology of lymphopenia and evaluating novel immunomodulatory therapies will help translate these results into future clinical trials.

Ejection Fraction by Echocardiography for a Selective Use of Magnetic Resonance After Infarction

Background Cardiac magnetic resonance (CMR) permits robust risk stratification of discharged ST-segment-elevation myocardial infarction patients, but its indiscriminate use in all cases is not feasible. We evaluated the utility of left ventricular ejection fraction (LVEF) by echocardiography for a selective use of CMR after ST-segment-elevation myocardial infarction. Methods Echocardiography and CMR were performed in 1119 patients discharged for ST-segment-elevation myocardial infarction included in a multicenter registry. The prognostic power of CMR beyond echocardiography-LVEF was assessed using adjusted C statistic, net reclassification improvement index, and integrated discrimination improvement index. Results During a 4.8-year median follow-up, 136 (12%) first major adverse cardiac events (MACE) occurred (47 cardiovascular deaths and 89 readmissions for acute heart failure). In the entire group, CMR-LVEF (but not echocardiography-LVEF) independently predicted MACE occurrence. The MACE rate significantly increased only in patients with CMR-LVEF<40% (≥50%: 7%, 40%-49%: 9%, <40%: 27%, P<0.001). Most patients displayed echocardiography-LVEF≥50% (629, 56%), and they had a low MACE rate (57/629, 9%). In patients with echocardiography-LVEF<50% (n=490, 44%), the MACE rate was also low in those with CMR-LVEF≥40% (24/278, 9%) but significantly increased in patients with CMR-LVEF<40% (55/212, 26%; P<0.001). Compared with echocardiography-LVEF, CMR-LVEF significantly improved MACE prediction in the group of patients with echocardiography-LVEF<50% (C statistic, 0.80 versus 0.72; net reclassification improvement index, 0.73; integrated discrimination improvement index, 0.10) but not in those with echocardiography-LVEF≥50% (C statistic 0.66 versus 0.66; net reclassification improvement index, 0.17; integrated discrimination improvement index, 0.01). Conclusions A straightforward strategy based on a selective use of CMR for risk prediction in ST-segment-elevation myocardial infarction patients with echocardiography-LVEF<50% can provide insights into patient care. The cost-effectiveness of this approach, as well as the direct implications in clinical management, should be further explored.

Prognostic value of vasodilator stress CMR in elderly patients with known or suspected chronic coronary syndrome

Background

In recent guidelines, non-invasive imaging techniques play a pivotal role in the management of chronic coronary syndrome (CCS). The elderly represent a large percentage of our routine CCS population and risk stratification in this scenario is challenging. The potential of vasodilator stress cardiovascular magnetic resonance (vs-CMR) for this purpose is unknown.

Purpose

We explored the prognostic value of the ischemic burden, as derived from vs-CMR, in elderly patients with known or suspected CCS.

Methods

From the general cohort of 6389 patients with known or suspected CCS submitted to undergo vs-CMR in our health department from 2001 to 2016, we performed a subanalysis of the 1225 patients &gt;70 year-old (mean age 77±5 years, 51% male). Clinical and vs-CMR characteristics were prospectively recorded. The ischemic burden (at stress first-pass perfusion imaging) was computed (using the 17-segment model). The occurrence of major adverse cardiac events (MACE) defined as all-cause death and/or non-fatal myocardial infarction (whichever occurred first) was retrospectively revised using the electronic regional health system registry.

Results

During a median follow-up of 2.7 years, 203 MACEs were registered (17%). Age (77±4 vs. 76±5 years) was not significantly different in patients with and without MACE. Larger left ventricular (LV) end-diastolic and end-systolic volume indexes, more depressed LV ejection fraction, more extensive areas with late gadolinium enhancement and ischemic burden were detected in patients with MACE (p&lt;0.001 for all comparisons). In non-revascularized patients (n=1118), the MACE rate ranged from 13% (in patients with 0–1 ischemic segments) to 35% (in those with &gt;8 ischemic segments, p&lt;0.001 for the trend). In the small subset of revascularized patients (n=107), revascularization exerted a non-significant protective effect only in patients with extensive ischemic burden (&gt;5 segments).

Conclusions

Vasodilator stress CMR represents a valuable tool to stratify risk in elderly patients with known or suspected CCS and might be helpful to guide decision-making.

Figure 1

Funding Acknowledgement

Type of funding source: None

A novel clinical and stress cardiac magnetic resonance score to predict long-term all-cause mortality in patients with known or suspected chronic coronary syndrome

Background

Vasodilator stress cardiac magnetic resonance (stressCMR) has shown robust diagnostic and prognostic value in patients with known or suspected chronic coronary syndrome (CCS). However, it is unknown whether integration of several prognostic stressCMR parameters, such as the ischemic burden (number of segments with first-pass stress-induced perfusion defects -PD-) and left ventricular ejection fraction (LVEF), with clinical variables can improve risk prediction in this population.

Purpose

We aim to explore the usefulness of a clinical-stressCMR score to predict the risk of all-cause mortality in patients with known or suspected CCS submitted to undergo a stressCMR.

Methods

We included 6187 patients in a large prospective multicenter registry (mean age 65.18±11.51 years, 37.3% female) which underwent stressCMR for known or suspected CCS. Several clinical and stressCMR variables were collected, such as LVEF, end-diastolic and end-systolic volume indices, ischemic burden and segments with necrosis (with late gadolinium enhancement imaging).

Results

During a mean and median follow-up of 5.85±3.82 years we registered 682 (11%) all-cause deaths. Several clinical and all stressCMR variables were associated with all-cause mortality in univariate analysis. However, the only independent predictors of all-cause mortality in multivariate analysis were age (HR 1.07 [1.06–1.08] per year, p&lt;0.001), male sex (HR 1.36 [1.15–1.61], p&lt;0.001), diabetes mellitus (HR 1.6 [1.37–1.87], p&lt;0.001), LVEF (0.98 [0.97–0.98] per %, p&lt;0.001) and ischemic burden (HR 1.04 [1.02–1.06] per segment with stress-induced PD, p=0.001). By means of the chi-square increase at each step of the stepwise multiparametric Cox regression we created a clinical-stressCMR score that included these variables (age, male sex, diabetes mellitus, LVEF and ischemic burden) kept in their continuous state if possible. This score showed a good performance to predict all-cause mortality (area under the curve = 0.716 [0.697–0.735], p&lt;0.001). Dividing the population into quintiles according to the clinical-stressCMR score allowed for a stratification of the annualized risk of all-cause mortality (0.39%/year, 0.94%/year, 1.62%/year, 2.63%/year and 3.83%/year, respectively; log-rank 420.33 and p&lt;0.001 for Kaplan-meier curves).

Conclusions

A novel clinical-stressCMR, which includes clinical (age, male sex, and diabetes mellitus) and stressCMR (LVEF and ischemic burden) variables, can provide robust prediction and stratification of the risk of all-cause mortality in a population of patients with know or suspected CCS.

Figure 1. Clinical-stress CMR score

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This study was funded by “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER” (PIE15/00013, PI17/01836, and CIBERCV16/11/00486 grants) and by Generalitat Valenciana (GV/2018/116).

Chest pain of unknown coronary origin: can exercise ECG testing contribute to long-term risk prediction on top of vasodilator stress cardiac magnetic resonance?

Background

The prognostic value of both exercise ECG testing (ExECG) and vasodilator stress cardiac magnetic resonance (VS-CMR) is well-known in patients with chest pain of unknown coronary origin. However, it is unknown whether performing both techniques can improve the risk stratification of these patients.

Purpose

We aim to confirm the additive prognostic value of ExECG and VS-CMR in a real-world cohort of patients with chest pain of unknown coronary origin.

Methods

We retrospectively included 288 patients in which ExECG and VS-CMR had been subsequently performed within one year. Clinical, ExECG and VS-CMR variables were registered. We performed univariate and multivariate analysis to check for the association of variables with the risk of MACE, defined as a combined endpoint of acute coronary syndrome (ACS), admission for heart failure (aHF) or all-cause death.

Results

During a mean follow-up of 4.2±2.15 years, we registered 27 MACE (15 ACS, 8 aHF and 8 all-cause deaths). The history of hypertension, previous coronary artery disease and/or coronary artery bypass grafting, lower maximal heart rate during ExECG (maxHR) and more extensive ischemic burden (segments with perfusion defects -PD- on stress first-pass perfusion) and myocardial necrosis (number of segments with necrosis at late gadolinium enhancement imaging) associated with the MACE endpoint. However, the only independent predictors of MACE were maxHR during ExECG (HR 0.98 [0.96–0.99], p=0.01) and more extensive segments with PD in the VS-CMR (HR 1.2 [1.07–1.34], p=0.002). We identified the best cut-off using the Youden index derived from receiver operating characteristics (ROC) analysis to predict MACE - it was ≤130bpm for maxHR during ExECG and ≥2 segments with PD on VS-CMR. These cathegories allowed us to stratify the annualized rate of MACE, which was very low (0.97%/year) in patients with normal maxHR and no PD on VS-CMR, intermediate in patients with only abnormal maxHR (1.98%/year) or PD on VS-CMR (3.24%/year) and high in patients with both abnormal maxHR and segments with PD (6.26%/year). Adding maxHR to the multivariable model including stress-induced PD by VS-CMR significantly improved the predictive power of MACE as derived from the continuous reclassification improvement index (0.47 [0.10–0.81], p&lt;0.05).

Conclusions

ExECG and VS-CMR can have an additive prognostic value to predict the long-term risk of MACE in patients with chest pain of unknown coronary origin. Patients with maxHR during ExECG ≤130bpm and ≥2 segments with PD on VS-CMR are at the highest risk of MACE.

Figure 1. MACE risk stratification.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This study was funded by “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER” (PIE15/00013, PI17/01836, and CIBERCV16/11/00486 grants) and by Generalitat Valenciana (GV/2018/116).

Complete revascularization of non-culprit lesions in stemi is associated with improved myocardial salvage and reduced microvascular obstruction: a cardiac magnetic resonance study

Background

The COMPLETE trial showed that routine and complete Percutaneous Coronary Intervention (PCI) of non-infarct related artery (non-IRA) lesions in STEMI was associated with a significant reduction in the rates of death or new myocardial infarction. However, whether this benefit is related to improved myocardial salvage and left ventricular (LV) function is unknown.

Methods

We prospectively included 465 patients with first STEMI reperfused by primary PCI. Late gadolinium-enhanced Cardiac Magnetic Resonance (CMR) was obtained during admission to measure the area at risk (AAR), IRA-infarct size (IS) as % LV mass, and myocardial salvage index (MSI) as % of AAR. The study was repeated in 392 of them at 6 months follow-up to compute LV volumes and ejection fraction (EF).

Results

Patients with three-vessel disease had larger IS than those with two or single vessel disease (25.4±14.5% vs 19.0±13.1% vs 19.0±12.8% LV mass respectively, p&lt;0.05), despite no differences in AAR (33±11% LV mass for all). Accordingly, MSI decreased progressively for one, two or three-vessel disease (42.4±31.4 vs 41.5±30.6 vs 25.1±31.3% AAR respectively, p&lt;0.01). The number of myocardial segments with microvascular obstruction (MVO) was also higher for three-vessel disease (1.9±1.9) than for two (1.1±1.7) or single-vessel disease (1.2±1.8), p&lt;0.05. Mean follow-up EF also decreased progressively with the number of vessels involved (50.7±9.4, 49.1±11.4 and, 44.4±11.2% respectively, p&lt;0.01). A total of 183 patients had multivessel disease. Among them, those with complete revascularization (n=51) had larger MSI (46.4±35.2 vs 34.5±29.3% AAR, p&lt;0.04) and were less likely to have MVO phenomenon (28.6 vs 49.2%, p&lt;0.05). However, no significant differences in the change in EF was observed between both groups (ΔEF:+4.4±6.2 vs +4.3±6.2%, p=0.985 for the interaction).

Conclusion

The presence and extent of multivessel disease influence myocardial salvage and MVO following primary PCI in STEMI. Improvement in myocardial salvage in the IRA territory and a reduction in microvascular obstruction may mediate the beneficial effects of complete revascularization.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Fundaciό La Marato TV3 2015303132, FIS PI15/00531. Partially funded with FEDER funds.

Impact of the dynamics of ejection fraction on risk stratification in a large multicenter registry of STEMI patients using sequential CMR

Background

Left ventricular ejection fraction (LVEF) has traditionally been used as the cornerstone for risk stratification after ST-segment elevation myocardial infarction (STEMI) and it can be accurately quantified by cine cardiovascular magnetic resonance (CMR). In recent years, the additional prognostic value of contrast CMR-derived infarct size (IS) and microvascular obstruction (MVO) has been demonstrated.

Purpose

We explored the impact of sequential assessment of CMR-derived LVEF on dynamic risk stratification after STEMI.

Methods

Data were obtained from three prospective registries of reperfused STEMI patients (n=1036) in whom LVEF, IS and MVO were sequentially quantified by CMR (at least at 1 week and at 6 months). Major adverse cardiac events (MACE) were defined as a combined clinical end-point: death or re-admission for acute heart failure (HF), whichever occurred first. Late events were regarded as those occurring after the 6-month CMR.

Results

During a mean and median follow-up of 5 years, 105 first MACE (10%, 36 deaths and 69 HF) and 82 late MACE (8%, 35 deaths and 47 HF) were registered. From 1-week to 6-month CMR, LVEF improved (49±12 vs. 53±12%), IS decreased (21±14 vs 17±12% of LV mass) and MVO vanished (1.3±1.9 vs. 0.1±0.7% of LV mass), p&lt;0.001 for all comparisons. At 1-week CMR, 207 patients (20%) displayed reduced LVEF (r-LVEF, &lt;40%), 328 (32%) mid-range LVEF (mr-LVEF, 40–50%) and 501 (48%) preserved LVEF (p-LVEF, &gt;50%). At 6-month CMR, 144 patients (14%) displayed r-LVEF, 247 (24%) mr-LVEF and 645 (62%) p-LVEF. The total MACE rate was higher (p&lt;0.001) only in patients with r-LVEF at 1 week (22%) vs. 7% in those with mr-LVEF and 7% in those with p-LVEF. Similarly, the late MACE rate was higher (p&lt;0.001) only in patients with r-LVEF at 6 months (20%) vs. 7% in those with mr-LVEF and 5% in those with p-LVEF. The late MACE rate was very low in patients with sustained mr- or p-LVEF (41/794, 5%), intermediate in those with improved LVEF from r-LVEF at 1 week to mr- or p-LVEF at 6 months (12/98, 12%) and high in patients with sustained r-LVEF (22/109, 20%) or worsened LVEF from mr- or p-LVEF at 1 week to r-LVEF at 6 months (7/35, 20%), p&lt;0.001 for the trend. Using a Markov approach, only r-LVEF (at any time assessed) significantly related to a higher MACE rate.

Conclusions

Of available CMR parameters, LVEF persists as the pivotal index for simple post-STEMI risk stratification. Mid-range or preserved LVEF in acute phase associates with excellent long-term outcome. Changes in LVEF provide valuable dynamic prognostic information. Maintenance of mid-range or preserved LVEF in chronic phase occurs in the majority of patients and associates with a very low risk of late clinical events. Whereas late improvement reaching at least mid-range LVEF exerts salutary effects, detection of reduced LVEF at this point identifies the small subset of patients at high risk in the long term.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This study was funded by “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER” (PIE15/00013, PI17/01836, and CIBERCV16/11/00486 grants).

Risk stratification in patients discharged for STEMI. Ejection fraction by echocardiography as the gatekeeper for a selective use of cardiac magnetic resonance

Background

CMR permits robust risk stratification of discharged STEMI patients but an indiscriminate use in all cases is unfeasible.

Purpose

We evaluated the usefulness of left ventricular ejection fraction (LVEF) by echocardiography (Echo) as the gatekeeper for identifying those patients discharged for ST-segment elevation myocardial infarction (STEMI) who benefit most from cardiac magnetic resonance (CMR) for prognostic purposes.

Methods

Echo and CMR were performed in 1119 patients discharged for STEMI included in a multicenter registry. The prognostic power of CMR beyond Echo-LVEF was assessed using C-statistic, net reclassification index (NRI) and integrated discrimination improvement index (IDI).

Results

During a 4.8-year median follow-up, 136 (12%) first major adverse cardiac events (MACE) occurred (47 cardiovascular deaths and 89 re-admissions for acute heart failure). Lesser Echo-LVEF and CMR-LVEF associated with the occurrence of MACE but only CMR-LVEF and microvascular obstruction were independent predictors. The MACE rate significantly increased only in patients with CMR-LVEF &lt;40% (≥50%: 7%, 40–49%: 9%, &lt;40%: 27%, p&lt;0.001). The majority of patients (629, 56%) displayed Echo-LVEF ≥50% and most of them (94%) were at the “safe zone” (CMR-LVEF &gt;40%). On the other hand, 490 patients (44%) exhibited Echo-LVEF &lt;50% and 33% of them were incorrectly classified either in the “safe zone” (CMR-LVEF ≥40%) or in the “risk zone” (CMR-LVEF &lt;40%). C-statistic, NRI and IDI demonstrated potent reclassification for MACE prediction by CMR in patients with Echo-LVEF &lt;50% but not in those with Echo-LVEF ≥50%.

Conclusions

Echo-LVEF &lt;50% identifies the subset of discharged STEMI patients who may benefit most from CMR in terms of long-term risk prediction.

Figure 1. LVEF reclassification

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This study was funded by “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER” (PIE15/00013, PI17/01836, and CIBERCV16/11/00486 grants).