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.

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.

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.

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.

Myocardial deformation in athletes measured with feature tracking cardiovascular magnetic resonance

Background

Morphological changes of the heart associated with exercise are well studied. However, changes in myocardial mechanics of athlete's heart are less understood. The aim of this study was to analyze myocardial deformation parameters in athletes and controls, using feature tracking cardiac magnetic resonance (FT-CMR).

Methods

In a cohort of 73 athletes who had been submitted to CMR at 1.5T and 3 T (mean age 31±12 years, 69% males), we used CMR-FT to measure longitudinal, circumferential and radial strain and strain rates of both ventricles. Left ventricle (LV) longitudinal, circumferential and radial dyssynchrony index (L-SDI, C-SDI and R-CDI, respectively) was calculated as the standard deviation of the calculated time to peak strain percentages of the cardiac cycle with segmental strain analysis. We also measured these parameters in 73 age-matched healthy subjects.

Results

In comparison to the control subjects, athletes revealed lower left and right ventricle global longitudinal strain (−14.24% vs. −13.31%, p=0.03, and −18.12% vs. −15.95% p=0.01, respectively) and right ventricular (RV) global radial strain (19.28 vs 15.74, p&lt;0.05) – Figure 1. There were no significant differences in LV global radial and circumferential strain. LV longitudinal, radial and circumferential systolic strain rate were also lower in athletes compared to controls (−0.69 s–1 vs. −0.78 s–1, p=0.04; 1.35 s–1 vs. 1.50 s–1, p=0.03: −0.92 s–1 vs −0.98 s–1, p=0.05, respectively). Regarding LV dyssynchrony index, we found no significant difference for L-SDI (10.76% vs. 10.72%, p=0.956), but athletes group showed lower C-SDI and R-SDI values (5.99% vs 4.84%, p=0.006, and 5.53% vs 4.47%, p=0.002).

Conclusion

Our study revealed attenuation of biventricular strain values and lower circumferential and radial LV dyssynchrony indexes in athletes, compared with healthy controls. We hypothesize that these differences may be related with exercise physiologic cardiac adaptations.

Funding Acknowledgement

Type of funding sources: None.

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.

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.

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.

Predictive Value of Cardiac Magnetic Resonance Feature Tracking after Acute Myocardial Infarction: A Comparison with Dobutamine Stress Echocardiography

In acute ST-segment elevation myocardial infarction (STEMI) late gadolinium enhancement (LGE) may underestimate segmental functional recovery. We evaluated the predictive value of cardiac magnetic resonance (CMR) feature-tracking (FT) for functional recovery and whether it incremented the value of LGE compared to low-dose dobutamine stress echocardiography (LDDSE) and speckle-tracking echocardiography (STE). Eighty patients underwent LDDSE and CMR within 5–7 days after STEMI and segmental functional recovery was defined as improvement in wall-motion at 6-months CMR. Optimal conventional and FT parameters were analyzed and then also applied to an external validation cohort of 222 STEMI patients. Circumferential strain (CS) was the strongest CMR-FT predictor and addition to LGE increased the overall accuracy to 74% and was especially relevant in segments with 50–74% LGE (AUC 0.60 vs. 0.75, p = 0.001). LDDSE increased the overall accuracy to 71%, and in the 50–74% LGE subgroup improved the AUC from 0.60 to 0.69 (p = 0.039). LGE + CS showed similar value as LGE + LDDSE. In the validation cohort, CS was also the strongest CMR-FT predictor of recovery and addition of CS to LGE improved overall accuracy to 73% although this difference was not significant (AUC 0.69, p = 0.44). Conclusion: CS is the strongest CMR-FT predictor of segmental functional recovery after STEMI. Its incremental value to LGE is comparable to that of LDDSE whilst avoiding an inotropic stress agent. CS is especially relevant in segments with 50–74% LGE where accuracy is lower and further testing is frequently required to clarify the potential for recovery.

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.

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).

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

Safety and tolerability of regadenoson in comparison with adenosine stress cardiovascular magnetic resonance: Data from a multicentre prospective registry

To assess the feasibility and incidence of immediate complications of stress cardiovascular magnetic resonance (CMR) with regadenoson in comparison with adenosine in a large referral population. This is a large, multicenter, prospective registry of vasodilator stress-CMR in a referral population. We recorded the clinical and demographic data, quality of test, CMR findings, hemodynamic data, and complications. Between January 2016 and July 2019, 2908 patients underwent stress-CMR, 2253 with regadenoson and 655 with adenosine. 25.1% of patients had previously known coronary artery disease (CAD). In 305 patients regadenoson was used due to presence of chronic obstructive pulmonary disease (COPD) or asthma, while in 1948 subjects regadenoson was used as first-line vasodilator. Quality was optimal in 90.0%, suboptimal in 9.5%, and poor in 0.5%. Images were diagnostic in 98.9%. After stress with regadenoson, aminophylline 200 mg was administered intravenously in all patients. No patient died or had severe immediate complications with regadenoson as opposed to 2 severe bronchospasm with adenosine (p = 0.05). 11 patients (0.5%) had non-severe complications with regadenoson and five patients (0.8%) with adenosine (p = n.s.). Only two patients (0.088%) had non-severe bronchospasm after regadenoson administration. All complications were solved in the CMR unit, with no need for further specific care. Factors significantly associated with presence of complications were history of COPD or asthma and detection of inducible ischaemia. Patients had significantly more minor symptoms when adenosine was used (66.0% vs. 18.4%, p < 0.0001). Stress-CMR with regadenoson is feasible, providing diagnostic information in a referral population. Regadenoson had an excellent safety profile and better tolerability than adenosine, with no serious immediate complications and low incidence of non-severe complications. Only inducible ischaemia and previous history of COPD or asthma were associated with complications after regadenoson-CMR. The incidence of minor symptoms was low.

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.

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

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.

A Novel Clinical and Stress Cardiac Magnetic Resonance (C-CMR-10) Score to Predict Long-Term All-Cause Mortality in Patients with Known or Suspected Chronic Coronary Syndrome

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 stressCMR with clinical variables in a simple clinical-imaging score can straightforwardly predict all-cause mortality in this population. We included 6187 patients in a large registry that underwent stressCMR for known or suspected CCS. Several clinical and stressCMR variables were collected, such as left ventricular ejection fraction (LVEF) and ischemic burden (number of segments with stress-induced perfusion defects (PD)). During a median follow-up of 5.56 years, we registered 682 (11%) all-cause deaths. The only independent predictors of all-cause mortality in multivariable analysis were age, male sex, diabetes mellitus (DM), LVEF and ischemic burden. Based on the weight of the chi-square increase at each step of the multivariable analysis, we created a simple clinical-stressCMR (C-CMR-10) score that included these variables (age ≥ 65 years = 3 points, LVEF ≤ 50% = 3 points, DM = 2 points, male sex = 1 point, and ischemic burden > 5 segments = 1 point). This 0 to 10 points C-CMR-10 score showed good performance to predict all-cause annualized mortality rate ranging from 0.29%/year (score = 0) to >4.6%/year (score ≥ 7). The goodness of the model and of the C-CMR-10 score was separately confirmed in 2 internal cohorts (n > 3000 each). We conclude that a novel and simple clinical-stressCMR score, which includes clinical and stressCMR variables, can provide robust prediction of the risk of long-term all-cause mortality in a population of patients with known or suspected CCS.

Magnetic resonance microscopy and correlative histopathology of the infarcted heart

Delayed enhancement cardiovascular magnetic resonance (MR) is the gold-standard for non-invasive assessment after myocardial infarction (MI). MR microscopy (MRM) provides a level of detail comparable to the macro objective of light microscopy. We used MRM and correlative histopathology to identify infarct and remote tissue in contrast agent-free multi-sequence MRM in swine MI hearts. One control group (n = 3 swine) and two experimental MI groups were formed: 90 min of ischemia followed by 1 week (acute MI = 6 swine) or 1 month (chronic MI = 5 swine) reperfusion. Representative samples of each heart were analysed by contrast agent-free multi-sequence (T1-weighting, T2-weighting, T2*-weighting, T2-mapping, and T2*-mapping). MRM was performed in a 14-Tesla vertical axis imager (Bruker-AVANCE 600 system). Images from MRM and the corresponding histopathological stained samples revealed differences in signal intensities between infarct and remote areas in both MI groups (p-value < 0.001). The multivariable models allowed us to precisely classify regions of interest (acute MI: specificity 92% and sensitivity 80%; chronic MI: specificity 100% and sensitivity 98%). Probabilistic maps based on MRM images clearly delineated the infarcted regions. As a proof of concept, these results illustrate the potential of MRM with correlative histopathology as a platform for exploring novel contrast agent-free MR biomarkers after MI.

P1475Risk stratification after STEMI. Ejection fraction by echocardiography as the gatekeeper for a selective use of cardiac magnetic resonance

Introduction

Cardiac magnetic resonance (CMR) has emerged as the most potent non-invasive imaging technique for risk stratification after ST-segment elevation myocardial infarction (STEMI) but an indiscriminate use in all patients is unfeasible. Echocardiography (Echo) has been universally used for prognostication in this scenario. We hypothesized that left ventricular ejection fraction (LVEF) by Echo can represent the gatekeeper for selecting those patients who benefit most from CMR for prognostic purposes.

Methods

Data were obtained from a large prospective registry of reperfused STEMI patients (n=516) in whom Echo (2D and Doppler variables) and CMR (cine images, microvascular obstruction and infarct size) were simultaneously recorded at pre-discharge (7±2 days). Major adverse cardiac events (MACE) were defined as a combined clinical end-point: death or re-admission for acute heart failure (whichever occurred first). Patients were categorized in reduced LVEF (r-LVEF, <40%), mid-range LVEF (mr-LVEF, 40–49%) and preserved LVEF (p-LVEF, ≥50%). Hierarchical multivariate Cox regression analyses including first clinical+Echo variables and then CMR variables where carried out. C-statistics, “net reclassification” (NRI) and “integrated discrimination” (IDI) indexes were obtained.

Results

During a mean and median follow-up of 4 years, 86 first MACE (17%) were registered (39 deaths and 47 re-admissions for acute heart failure). In the whole study group (n=516), the independent predictors of MACE were time to revascularization (min), GRACE score, CMR-LVEF (%) and CMR-microvascular obstruction (% of LV mass); C-statistic 0.82 (p<0.001). The MACE rate in patients with r-LVEF, mr-LVEF and p-LVEF was 47%, 23% and 11% by Echo-LVEF and 45%, 17% and 8% by CMR-LVEF. LVEF was lower by CMR than by Echo (51±13 vs. 54±10, p<0.001) and r-LVEF was more frequently detected by CMR (n=94, 18%) than by Echo (n=48, 9%), p<0.001. CMR significantly improved clinical+Echo stratification in those 112 patients (22%) with mr-Echo-LVEF (C-statistitics 0.74 vs 0.82; NRI and IDI: p<0.05) but it did not in those 355 patients (69%) with p-Echo-LVEF (C-statistitics 0.75 vs 0.76; NRI and IDI: non-significant) and in those 49 patients (9%) with r-Echo-LVEF (C-statistitics 0.77 vs 0.77; NRI and IDI: non-significant).

Figure 1. Risk stratification after STEMI

Conclusions

Applied in an individualized manner, Echo-LVEF appears as a useful gatekeeper for a selective use of CMR soon after STEMI for prognostic purposes. The event rate is high in patients with reduced Echo-LVEF and low in those with preserved Echo-LVEF; CMR does not seem to significantly improve risk stratification in these scenarios. Nevertheless, the occurrence of mid-range Echo-LVEF permits discriminating the specific subset of STEMI patients (less than a quarter) who really benefit from pre-discharge CMR in terms of risk assessment.

Acknowledgement/Funding

Funded by “Instituto de Salud Carlos III”/FEDER (PIE15/00013, PI17/01836, and CIBERCV16/11/00486 grants) and Generalitat Valenciana (GV/2018/116).

393Ischemic burden by vasodilator stress CMR predicts long-term all-cause death and the effect of revascularization in patients with known or suspected stable ischemic heart disease

Background

In patients with stable ischemic heart disease (SIHD) the effect of revascularization on all-cause death (the most verifiable clinical event) is unknown.

Objectives

We explored the potential of the ischemic burden as derived from vasodilator stress cardiovascular magnetic resonance (CMR) to guide decision-making in this scenario.

Methods

In a large prospective multicenter registry, we recruited 6389 patients (mean age 65±11 years, 38% female) submitted to undergo vasodilator stress CMR for known or suspected SIHD. Baseline and CMR characteristics were prospectively recorded. The ischemic burden (at vasodilator stress first-pass perfusion imaging) and necrosis extent (at late enhancement imaging) were computed (17-segment model). The effect of CMR-related revascularization (within the following three months) on all-cause death (revised using the unified regional electronic health system registry) was explored.

Results

During a 5.75-year median follow-up, 717 (11.2%) all-cause deaths were documented. In multivariable analyses, more extensive ischemic burden (per 1-segment increase) independently related to all-cause death (1.05 [1.03–1.07], p<0.001). In 1034 patients (517 revascularized, 517 non-revascularized) strictly 1:1 matched for the independent predictors of outcome and of undergoing CMR-related revascularization (age, diabetes mellitus, male sex, LVEF, ischemic burden and necrosis extent), CMR-related revascularization did not significantly alter all-cause death rate (13.3% vs. 13.3%, p=0.54). Nevertheless, a potent interaction existed with the ischemic burden (p<0.001). CMR-related revascularization independently reduced the risk of all-cause death in 430 patients with ischemic burden >5 segments (9.3% vs. 16.3%, HR 0.56 [0.32–0.98], p=0.02) but it independently increased risk in 604 patients with ischemic burden ≤5 segments (16.2% vs. 11.3%, HR 1.59 [1.03–2.45], p=0.037).

Figure 1. CMR-related revascularization

Conclusions

In patients with known or suspected stable ischemic heart disease the ischemic burden as derived from vasodilator stress CMR can be helpful to predict the effect of revascularization on long-term all-cause death.

Acknowledgement/Funding

Funded by “Instituto de Salud Carlos III”/FEDER (PIE15/00013, PI17/01836, and CIBERCV16/11/00486 grants) and Generalitat Valenciana (GV/2018/116).

P6397Ejection fraction by cardiac magnetic resonance 6 months after STEMI: impact on risk stratification in chronic phase

Background

Left ventricular ejection fraction (LVEF) has traditionally been used as the cornerstone for risk stratification after 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) soon after infarction has been demonstrated. The usefulness of CMR-derived LVEF in chronic phase for risk stratification late after STEMI is unclear.

Purpose

We hypothesized that 6-month CMR-derived LVEF can contribute in the prediction of clinical events late after STEMI beyond pre-discharge LVEF, IS and MVO.

Methods

Data were obtained from a prospective registry of reperfused STEMI patients (n=456) who were stable 6 months after infarction and in whom 1-week and 6-month CMR-derived LVEF, IS and MVO were sequentially quantified. Major adverse cardiac events (MACE) were defined as a combined clinical end-point that included death or re-admission for acute decompensated heart failure (r-ADHF), whichever occurred first, occurring after the 6-month CMR.

Results

During a mean and median follow-up of 6 years, 56 late MACE (12%, 32 deaths and 24 r-ADHF) were registered. From 1-week to 6-month, CMR parameters exhibited significant dynamic changes (p<0.001): LVEF improved (52±12 vs. 56±13%), IS decreased (21±14 vs. 18±12% of LV mass) and MVO vanished (2±4 vs. 0±1% of LV mass). At 6-month CMR, 60 patients (13%) displayed reduced LVEF (<40%), 69 (15%) mid-range LVEF (40–50%) and 327 (72%) preserved LVEF (≥50%). Late MACE rates were 28% in patients with reduced LVEF, 14% in those with mid-range LVEF and 9% in those with preserved LVEF at 6-month CMR (p<0.001 for the trend). After adjustment for baseline characteristics and for 1-week and 6-month CMR parameters, more preserved LVEF at 6 months independently associated with a lower risk of MACE late after STEMI (hazard ratio 0.96 [0.94–0.98] per 1% increase).

Conclusions

Dramatic dynamic changes occur in CMR parameters within the first months after STEMI. Reassessment of CMR-derived LVEF in chronic phase in those patients who remain stable provides relevant prognostic information for long-term risk stratification.

Acknowledgement/Funding

Funded by “Instituto de Salud Carlos III”/FEDER (PIE15/00013, PI17/01836, and CIBERCV16/11/00486 grants) and Generalitat Valenciana (GV/2018/116).

Prediction of Reverse Remodeling at Cardiac MR Imaging Soon after First ST-Segment-Elevation Myocardial Infarction: Results of a Large Prospective Registry

PURPOSE

To assess predictors of reverse remodeling by using cardiac magnetic resonance (MR) imaging soon after ST-segment-elevation myocardial infarction (STEMI).

MATERIALS AND METHODS

Written informed consent was obtained from all patients, and the study protocol was approved by the institutional committee on human research, ensuring that it conformed to the ethical guidelines of the 1975 Declaration of Helsinki. Five hundred seven patients (mean age, 58 years; age range, 24-89 years) with a first STEMI were prospectively studied. Infarct size and microvascular obstruction (MVO) were quantified at late gadolinium-enhanced imaging. Reverse remodeling was defined as a decrease in left ventricular (LV) end-systolic volume index (LVESVI) of more than 10% from 1 week to 6 months after STEMI. For statistical analysis, a simple (from a clinical perspective) multiple regression model preanalyzing infarct size and MVO were applied via univariate receiver operating characteristic techniques.

RESULTS

Patients with reverse remodeling (n = 211, 42%) had a lesser extent (percentage of LV mass) of 1-week infarct size (mean ± standard deviation: 18% ± 13 vs 23% ± 14) and MVO (median, 0% vs 0%; interquartile range, 0%-1% vs 0%-4%) than those without reverse remodeling (n = 296, 58%) (P < .001 in pairwise comparisons). The independent predictors of reverse remodeling were infarct size (odds ratio, 0.98; 95% confidence interval [CI]: 0.97, 0.99; P = .04) and MVO (odds ratio, 0.92; 95% CI: 0.86, 0.99; P = .03). Once infarct size and MVO were dichotomized by using univariate receiver operating characteristic techniques, the only independent predictor of reverse remodeling was the presence of simultaneous nonextensive infarct-size MVO (infarct size < 30% of LV mass and MVO < 2.5% of LV mass) (odds ratio, 3.2; 95% CI: 1.8, 5.7; P < .001).

CONCLUSION

Assessment of infarct size and MVO with cardiac MR imaging soon after STEMI enables one to make a decision in the prediction of reverse remodeling.

Pharmacological stress cardiovascular magnetic resonance: feasibility and safety in a large multicentre prospective registry

AIMS

To assess the feasibility and incidence of immediate complications of stress cardiovascular magnetic resonance (CMR) and to determine associated factors.

METHODS AND RESULTS

This was a large multicentre, prospective registry of pharmacologic stress CMR in a referral population. We used dipyridamole when no contraindication was present and dobutamine in the remaining patients. Stress CMR was performed at 1.5 T. We recorded the clinical and demographic data, quality of test, CMR findings, haemodynamic data, and complications. Stress CMR was performed in 11 984 patients (98.2% of requested), using dipyridamole in 95.4% and dobutamine in 4.6%. The study could not be performed due to claustrophobia in 0.2%. Quality was optimal in 93.4%, suboptimal in 6.2%, and poor in 0.4% of studies. Images were diagnostic in 97.6% of patients (98.7% with dipyridamole and 75.1% with dobutamine, P < 0.0001). No patient died or had acute myocardial infarction during the test. Ten patients (0.08%) had severe immediate complications, seven after dipyridamole and two after dobutamine (P = 0.062), and one anaphylactic shock post-gadolinium. The only factor significantly associated with higher incidence of serious complications was the detection of inducible ischaemia. Incidence of non-severe complications was low (1.5%), severe controlled chest pain being the most frequent. Minor symptoms occurred frequently (24.8%). Both were significantly more frequent when dobutamine was used.

CONCLUSION

Performance of stress CMR is safe in a referral population. Inducible ischaemia was the only factor identified which was associated with serious complications. The incidence of non-severe complications and minor symptoms was greater with dobutamine.

Prognostic value of myocardial ischemia and necrosis in depressed left ventricular function: a multicenter stress cardiac magnetic resonance registry

INTRODUCTION AND OBJECTIVES

The incremental prognostic value of inducible myocardial ischemia over necrosis derived by stress cardiac magnetic resonance in depressed left ventricular function is unknown. We determined the prognostic value of necrosis and ischemia in patients with depressed left ventricular function referred for dipyridamole stress perfusion magnetic resonance.

METHODS

In a multicenter registry using stress magnetic resonance, the presence (≥ 2 segments) of late enhancement and perfusion defects and their association with major events (cardiac death and nonfatal infarction) was determined.

RESULTS

In 391 patients, perfusion defect or late enhancement were present in 224 (57%) and 237 (61%). During follow-up (median, 96 weeks), 47 major events (12%) occurred: 25 cardiac deaths and 22 myocardial infarctions. Patients with major events displayed a larger extent of perfusion defects (6 segments vs 3 segments; P <.001) but not late enhancement (5 segments vs 3 segments; P =.1). Major event rate was significantly higher in the presence of perfusion defects (17% vs 5%; P =.0005) but not of late enhancement (14% vs 9%; P =.1). Patients were categorized into 4 groups: absence of perfusion defect and absence of late enhancement (n = 124), presence of late enhancement and absence of perfusion defect (n = 43), presence of perfusion defect and presence of late enhancement (n = 195), absence of late enhancement and presence of perfusion defect (n = 29). Event rate was 5%, 7%, 16%, and 24%, respectively (P for trend = .003). In a multivariate regression model, only perfusion defect (hazard ratio = 2.86; 95% confidence interval, 1.37-5.95]; P = .002) but not late enhancement (hazard ratio = 1.70; 95% confidence interval, 0.90-3.22; P =.105) predicted events.

CONCLUSIONS

In depressed left ventricular function, the presence of inducible ischemia is the strongest predictor of major events.

Right ventricular involvement in anterior myocardial infarction: a translational approach

AIMS

The aim of the present study was to evaluate the involvement of the right ventricle (RV) in reperfused anterior ST-elevation myocardial infarction (STEMI).

METHODS AND RESULTS

Left anterior descending (LAD)-perfused area (using thioflavin-S staining after selective infusion in proximal LAD artery, %), infarct size (using triphenyltetrazolium chloride staining, %), and salvaged myocardium (% of LAD-perfused area) in the right and left ventricle (LV) were quantified in a 90-min LAD occlusion 3-day reperfusion model in swine (n = 8). Additionally, we studied, using cardiovascular magnetic resonance, 20 patients with a first STEMI due to proximal LAD occlusion treated with primary angioplasty. Area at risk (T2-weighted sequence, %), infarct size (late enhancement imaging, %), and salvaged myocardium (% of area at risk) in the right and LV were quantified. In swine, a large LAD-perfused area was detected both in the right and LV (30 +/- 5 vs. 62 +/- 15%, P< 0.001) but more salvaged myocardium (94 +/- 6 vs. 73 +/- 11%, P< 0.001) resulted in a smaller right ventricular infarct size (2 +/- 1 vs. 16 +/- 5%, P< 0.001). Similarly, in patients a large area at risk was detected both in the right and LV (34 +/- 13 vs. 43 +/- 12%, P = 0.02). More salvaged myocardium (94 +/- 10 vs. 33 +/- 26%, P < 0.001) resulted in a smaller infarct size (2 +/- 3 vs. 30 +/- 16%, P< 0.001) in the RV.

CONCLUSION

In reperfused extensive anterior STEMI, a large area of the RV is at risk but the resultant infarct size is small.

Prognostic and therapeutic implications of dipyridamole stress cardiovascular magnetic resonance on the basis of the ischaemic cascade

OBJECTIVE

To determine the prognostic and therapeutic implications of stress perfusion cardiovascular magnetic resonance (CMR) on the basis of the ischaemic cascade.

SETTING

Single centre study in a teaching hospital in Spain.

PATIENTS

Dipyridamole stress CMR was performed on 601 patients with ischaemic chest pain and known or suspected coronary artery disease. On the basis of the ischaemic cascade, patients were categorised in C1 (no evidence of ischaemia, n = 354), C2 (isolated perfusion deficit at stress first-pass perfusion imaging, n = 181) and C3 (simultaneous perfusion deficit and inducible wall motion abnormalities, n = 66). CMR-related revascularisation (n = 102, 17%) was defined as the procedure prompted by the CMR results and carried out within the next three months.

RESULTS

During a median follow-up of 553 days, 69 major adverse cardiac events (MACE), including 21 cardiac deaths, 14 non-fatal myocardial infarctions and 34 admissions for unstable angina with documented abnormal angiography were detected. In non-revascularised patients (n = 499), the MACE rate was 4% (14/340) in C1, 20% (26/128) in C2 and 39% (12/31) in C3 (adjusted p value = 0.004 vs C2 and <0.001 vs C1). CMR-related revascularisation had neutral effects in C2 (20% vs 19%, 1.1 (0.5 to 2.4), p = 0.7) but independently reduced the risk of MACE in C3 (39% vs 11%, 0.2 (0.1 to 0.7), p = 0.01).

CONCLUSIONS

Dypiridamole stress CMR is able to stratify risk on the basis of the ischaemic cascade. A small group of patients with severe ischaemia-simultaneous perfusion deficit and inducible wall motion abnormalities-are at the highest risk and benefit most from MACE reduction due to revascularisation.

Prognostic Value of Dipyridamole Stress Cardiovascular Magnetic Resonance Imaging in Patients With Known or Suspected Coronary Artery Disease

OBJECTIVES

We evaluated the prognostic value of dipyridamole stress cardiovascular magnetic resonance imaging (CMR) in patients with chest pain and known or suspected coronary artery disease.

BACKGROUND

Stress perfusion CMR has been incorporated in daily practice. Data on its prognostic value are preliminary.

METHODS

Dipyridamole stress CMR was performed in 420 patients with chest pain and known or suspected coronary artery disease. The extent (number of segments according to the 17-segment model) of abnormal wall motion at rest (AWM-rest), abnormal wall motion with dipyridamole (AWM-D), perfusion deficit (at stress first-pass perfusion imaging), and delayed enhancement (at late enhancement imaging) were analyzed.

RESULTS

During a median follow-up of 420 days, 41 major adverse cardiac events (MACE), including 9 cardiac deaths, 14 nonfatal myocardial infarctions, and 18 readmissions for unstable angina with documented abnormal angiography, were documented. The MACE were more frequent in patients with significant (>1 segment) AWM-rest (22% vs. 5%), AWM-D (21% vs. 4%), perfusion deficit (17% vs. 5%), and delayed enhancement (20% vs. 6%; p <0.0001 in all cases). In a multivariate analysis adjusted for baseline characteristics, the extent of AWM-D was independently related to MACE (hazard ratio [HR] 1.15 [95% confidence interval (CI) 1.06 to 1.24] per segment; p = 0.0006) and to major events (cardiac death or nonfatal myocardial infarction; HR 1.15 [95% CI 1.05 to 1.26] per segment; p = 0.002).

CONCLUSIONS

Dipyridamole stress CMR is useful for predicting the outcome of patients with known or suspected coronary artery disease.

Evolution of 5 cardiovascular magnetic resonance-derived viability indexes after reperfused myocardial infarction

BACKGROUND

The objective of this study was to evaluate the simultaneous evolution of 5 cardiovascular magnetic resonance-derived myocardial viability indexes.

METHODS

We studied 72 patients with a first ST-elevation myocardial infarction and sustained TIMI 3 flow. In the first week and in the sixth month of the study, using cardiovascular magnetic resonance imaging, we determined wall thickening (WT) and the following viability indexes: wall thickness, WT with low-dose dobutamine, microvascular perfusion in first-pass imaging, microvascular obstruction in late-enhancement imaging, and transmural extent of necrosis.

RESULTS

In 250 dysfunctional segments, the evolution outcomes for the viability indexes were as follows: (1) wall thickness thinned (8.6 +/- 2.9 versus 7.7 +/- 3 mm, P < .001), (2) WT with low-dose dobutamine improved (1.5 +/- 1.9 versus 2.6 +/- 3 mm, P < .001), (3) the number of segments showing abnormal microvascular perfusion in first-pass imaging decreased (22% versus 7%, P < .001), (4) the number of segments showing microvascular obstruction in late-enhancement imaging decreased (14% versus 2%, P < .001), and (5) the transmural extent of necrosis remained stable throughout follow-up (56% +/- 40% versus 54% +/- 39%, P = .3).

CONCLUSIONS

After reperfused myocardial infarction, dynamic changes in wall thickness, contractile reserve, microvascular perfusion, and microvascular obstruction take place. These changes may affect their accuracy as viability indexes early after myocardial infarction. The transmural extent of necrosis does not vary, however.