Comparison of global myocardial strain assessed by cardiovascular magnetic resonance tagging and feature tracking to infarct size at predicting remodelling following STEMI

[Predictive value of cardiac magnetic resonance imaging for adverse left ventricular remodeling after acute ST-segment elevation myocardial infarction]

OBJECTIVE

To assess the value of cardiac magnetic resonance (CMR) imaging for predicting adverse left ventricular remodeling in patients with ST-segment elevation myocardial infarction (STEMI).

METHODS

We retrospectively analyzed the clinical data and serial CMR (cine and LGE sequences) images of 86 STEMI patients within 1 week and 5 months after percutaneous coronary intervention (PCI), including 25 patients with adverse LV remodeling and 61 without adverse LV remodeling, defined as an increase of left ventricular end-systolic volume (LVESV) over 15% at the second CMR compared to the initial CMR. The CMR images were analyzed for LV volume, infarct characteristics, and global and infarct zone myocardial function. The independent predictors of adverse LV remodeling following STEMI were analyzed using univariate and multivariate Logistic regression methods.

RESULTS

The initial CMR showed no significant differences in LV volume or LV ejection fraction (LVEF) between the two groups, but the infarct mass and microvascular obstructive (MVO) mass were significantly greater in adverse LV remodeling group (P < 0.05). Myocardial injury and cardiac function of the patients recovered over time in both groups. At the second CMR, the patients with adverse LV remodeling showed a significantly lower LVEF, a larger left ventricular end-systolic volume index (LVESVI) and a greater extent of infarct mass (P < 0.001) with lower global peak strains and strain rates in the radial, circumferential, and longitudinal directions (P < 0.05), infarct zone peak strains in the 3 directions, and infarct zone peak radial and circumferential strain rates (P < 0.05). The independent predictors for adverse LV remodeling following STEMI included the extent of infarct mass (AUC=0.793, 95% CI: 0.693-0.873; cut-off value: 30.67%), radial diastolic peak strain rate (AUC=0.645, 95% CI: 0.534-0.745; cut-off value: 0.58%), and RAAS inhibitor (AUC= 0.699, 95% CI: 0.590-0.793).

CONCLUSION

The extent of infarct mass, peak radial diastolic strain rate, and RAAS inhibitor are independent predictors of adverse LV remodeling following STEMI.

Diagnostic performance of cardiac magnetic resonance segmental myocardial strain for detecting microvascular obstruction and late gadolinium enhancement in patients presenting after a ST-elevation myocardial infarction

Background

Microvascular obstruction (MVO) and Late Gadolinium Enhancement (LGE) assessed in cardiac magnetic resonance (CMR) are associated with adverse outcome in patients with ST-elevation myocardial infarction (STEMI). Our aim was to analyze the diagnostic performance of segmental strain for the detection of MVO and LGE.

Methods

Patients with anterior STEMI, who underwent additional CMR were enrolled in this sub-study of the CARE-AMI trial. Using CMR feature tracking (FT) segmental circumferential peak strain (SCS) was measured and the diagnostic performance of SCS to discriminate MVO and LGE was assessed in a derivation and validation cohort.

Results

Forty-eight STEMI patients (62 ± 12 years old), 39 (81%) males, who underwent CMR (i.e., mean 3.0 ± 1.5 days) after primary percutaneous coronary intervention (PCI) were included. All patients presented with LGE and in 40 (83%) patients, MVO was additionally present. Segments in all patients were visually classified and 146 (19%) segments showed MVO (i.e., LGE+/MVO+), 308 (40%) segments showed LGE and no MVO (i.e., LGE+/MVO–), and 314 (41%) segments showed no LGE (i.e., LGE–). Diagnostic performance of SCS for detecting MVO segments (i.e., LGE+/MVO+ vs. LGE+/MVO–, and LGE–) showed an AUC = 0.764 and SCS cut-off value was –11.2%, resulting in a sensitivity of 78% and a specificity of 67% with a positive predictive value (PPV) of 30% and a negative predictive value (NPV) of 94% when tested in the validation group. For LGE segments (i.e., LGE+/MVO+ and LGE+/MVO– vs. LGE–) AUC = 0.848 and SCS with a cut-off value of –13.8% yielded to a sensitivity of 76%, specificity of 74%, PPV of 81%, and NPV of 70%.

Conclusion

Segmental strain in STEMI patients was associated with good diagnostic performance for detection of MVO+ segments and very good diagnostic performance of LGE+ segments. Segmental strain may be useful as a potential contrast-free surrogate marker to improve early risk stratification in patients after primary PCI.

Protective Value of Aspirin Loading Dose on Left Ventricular Remodeling After ST-Elevation Myocardial Infarction

Aims

Left ventricular (LV) remodeling after ST-elevation myocardial infarction (STEMI) is a complex process, defined as changes of LV volumes over time. CMR feature tracking analysis (CMR-FT) offers an accurate quantitative assessment of LV wall deformation and myocardial contractile function. This study aimed to evaluate the role of myocardial strain parameters in predicting LV remodeling and to investigate the effect of Aspirin (ASA) dose before primary coronary angioplasty (pPCI) on myocardial injury and early LV remodeling.

Methods and Results

Seventy-eight patients undergoing CMR, within 9 days from symptom onset and after 6 months, were enrolled in this cohort retrospective study. We divided the study population into three groups based on a revised Bullock's classification and we evaluated the role of baseline CMR features in predicting early LV remodeling. Regarding CMR strain analysis, worse global circumferential and longitudinal strain (GCS and GLS) values were associated with adverse LV remodeling. Patients were also divided based on pre-pPCI ASA dosage. Significant differences were detected in patients receiving ASA 500 mg dose before pPCI, which showed lower infarct size extent and better strain values compared to those treated with ASA 250 mg. The stepwise multivariate logistic regression analysis, adjusted for covariates, indicated that a 500 mg ASA dose remained an inverse independent predictor of early adverse LV remodeling.

Conclusion

GCS and GLS have high specificity to detect early LV adverse remodeling. We first reported a protective effect of ASA loading dose of 500 mg before pPCI on LV myocardial damage and in reducing early LV adverse remodeling.

Assessment of late gadolinium enhancement-negative chronic total occlusion by longitudinal strain analysis using cardiac magnetic resonance imaging

BACKGROUND

Strain analysis has become commonly used in clinical practice in various heart diseases.

PURPOSE

To explore whether late gadolinium enhancement (LGE)-negative areas with coronary artery chronic total occlusion (CTO) appear normal when analyzed for longitudinal strain using cardiac magnetic resonance (CMR) imaging.

MATERIAL AND METHODS

A total of 16 patients and 31 healthy controls who underwent 1.5-T MR at our hospital between January 2015 and July 2017 were included in the study. The LGE-CMR of patients with CTO was negative. Left ventricular functional parameters, segmental longitudinal strain/strain rate, and perfusion parameters were measured using CVI42 software.

RESULTS

For myocardial segments supplied by CTO vessels, systolic longitudinal strain rate (SLSR)was significantly lower than that of healthy controls, and diastolic longitudinal strain rate (DLSR) was significantly higher (1.19 1/s vs. 1.02 1/s; P = 0.018). Moreover, longitudinal strain (LS), SLSR, and DLSR did not differ between good and poor collateral circulation. Perfusion index of CTO territory segments was lower than non-CTO territory segments (0.20 vs. 0.22; P = 0.027). No correlation was found between longitudinal strain parameters and perfusion parameters.

CONCLUSION

Although LGE-CMR was negative in patients with CTO, the myocardial SLSR of CTO territory segments was significantly lower than that of healthy controls.

Myocardial Deformation Assessed by MR Feature Tracking in Groups of Patients With Ischemic Heart Disease

BACKGROUND

Global myocardial strain assessments have been shown to provide useful measures of contractility in many diseases, but whether feature tracking (FT)-derived strain at rest can differentiate ischemic myocardium from infarcted and remote myocardium in patients with coronary artery disease (CAD) remains unclear.

PURPOSE

To evaluate the performance of magnetic resonance imaging FT-derived strain in the detection of regional myocardial deformation in ischemic, infarcted, and apparent normal myocardium in CAD.

STUDY TYPE

Retrospective POPULATION: A total of 109 patients with CAD.

FIELD STRENGTH/SEQUENCES

Steady-state free-precession rest cine, T1-weighted saturation-recovery fast gradient echo stress/rest perfusion, and two-dimensional phase-sensitive inversion recovery breath-hold late gadolinium enhancement (LGE) tests were performed at 3.0 T.

ASSESSMENT

Based on perfusion and LGE images, left ventricular (LV) myocardial segments of CAD patients were categorized into ischemic, infarcted, and negative groups. The FT longitudinal (LS) and circumferential strain (CS) of normal subjects and the three CAD groups were calculated. Z-scores of each segment of CAD patients were calculated.

STATISTIC TESTS

χ² testing, analysis of variance (ANOVA), and Kruskal-Wallis tests. Z-scores were used to compare the strain between CAD groups.

RESULTS

There were significant differences in global LS (GLS) and CS (GCS) between healthy controls (GLS: -19.0% ± 1.4%, GCS, -20.9% ± 1.8%), ischemia (GLS: -17.4% ± 2.1%, GCS, -19.6% ± 1.9%), infarction (GLS: -16.4% ± 1.9%, GCS, -17.8% ± 1.9%), and negative patients (GLS: -17.7% ± 1.4%, GCS, -20.9% ± 2.4%) (all P < 0.05). There were significant differences in regional LS and CS between ischemic (LS, -16.1% ± 5.0%, CS, -18.7% ± 5.0%), infarcted (LS, -14.8% ± 5.2%, CS, -15.3% ± 4.8%), and negative segments (LS, -17.6% ± 5.2%, CS, -19.8% ± 4.8%) (all P < 0.05). The differences in the z-scores of regional LS and CS between the ischemic, infarcted, and negative segments were also significant (all P < 0.05).

DATA CONCLUSION

FT-derived rest strain indices of the LV myocardium of CAD patients were higher compared to healthy controls and varied between ischemic, infarcted, and negative segments.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY: Stage 5.

Cardiovascular Determinants of Aerobic Exercise Capacity in Adults With Type 2 Diabetes

OBJECTIVE

To assess the relationship between subclinical cardiac dysfunction and aerobic exercise capacity (peak VO₂) in adults with type 2 diabetes (T2D), a group at high risk of developing heart failure.

RESEARCH DESIGN AND METHODS

Cross-sectional study. We prospectively enrolled a multiethnic cohort of asymptomatic adults with T2D and no history, signs, or symptoms of cardiovascular disease. Age-, sex-, and ethnicity-matched control subjects were recruited for comparison. Participants underwent bioanthropometric profiling, cardiopulmonary exercise testing, and cardiovascular magnetic resonance with adenosine stress perfusion imaging. Multivariable linear regression analysis was undertaken to identify independent associations between measures of cardiovascular structure and function and peak VO₂.

RESULTS

A total of 247 adults with T2D (aged 51.8 ± 11.9 years, 55% males, 37% black or south Asian ethnicity, HbA_1c 7.4 ± 1.1% [57 ± 12 mmol/mol], and duration of diabetes 61 [32-120] months) and 78 control subjects were included. Subjects with T2D had increased concentric left ventricular remodeling, reduced myocardial perfusion reserve (MPR), and markedly lower aerobic exercise capacity (peak VO₂ 18.0 ± 6.6 vs. 27.8 ± 9.0 mL/kg/min; P < 0.001) compared with control subjects. In a multivariable linear regression model containing age, sex, ethnicity, smoking status, and systolic blood pressure, only MPR (β = 0.822; P = 0.006) and left ventricular diastolic filling pressure (E/e') (β = -0.388; P = 0.001) were independently associated with peak VO₂ in subjects with T2D.

CONCLUSIONS

In a multiethnic cohort of asymptomatic people with T2D, MPR and diastolic function are key determinants of aerobic exercise capacity, independent of age, sex, ethnicity, smoking status, or blood pressure.

Global longitudinal strain by feature tracking for optimized prediction of adverse remodeling after ST-elevation myocardial infarction

BACKGROUND

The role of left ventricular (LV) myocardial strain by cardiac magnetic resonance feature tracking (CMR-FT) for the prediction of adverse remodeling following ST-elevation myocardial infarction (STEMI), as well as its prognostic validity compared to LV ejection fraction (LVEF) and CMR infarct severity parameters, is unclear. This study aimed to evaluate the independent and incremental value of LV strain by CMR-FT for the prediction of adverse LV remodeling post-STEMI.

METHODS

STEMI patients treated with primary percutaneous coronary intervention were enrolled in this prospective observational study. CMR core laboratory analysis was performed to assess LVEF, infarct pathology and LV myocardial strain. The primary endpoint was adverse remodeling, defined as ≥ 20% increase in LV end-diastolic volume from baseline to 4 months.

RESULTS

From the 232 patients included, 38 (16.4%) reached the primary endpoint. Global longitudinal strain (GLS), global radial strain, and global circumferential strain were all predictive of adverse remodeling (p < 0.01 for all), but only GLS was an independent predictor of adverse remodeling (odds ratio: 1.36[1.03-1.78]; p = 0.028) after adjustment for strain parameters, LVEF and CMR markers of infarct severity. A GLS > - 14% was associated with a fourfold increase in the risk for LV remodeling (odds ratio: 4.16[1.56-11.13]; p = 0.005). Addition of GLS to a baseline model comprising LVEF, infarct size and microvascular obstruction resulted in net reclassification improvement of 0.26 ([0.13-0.38]; p < 0.001) and integrated discrimination improvement of 0.02 ([0.01-0.03]; p = 0.006).

CONCLUSIONS

In STEMI survivors, determination of GLS using CMR-FT provides important prognostic information for the development of adverse remodeling that is incremental to LVEF and CMR markers of infarct severity.

CLINICAL TRIAL REGISTRATION

NCT04113356.

Recovery and prognostic value of myocardial strain in ST-segment elevation myocardial infarction patients with a concurrent chronic total occlusion

Objectives

Global left ventricular (LV) function is routinely used to assess cardiac function; however, myocardial strain is able to identify more subtle dysfunction. We aimed to determine the recovery and prognostic value of featuring tracking (FT) cardiovascular magnetic resonance (CMR) strain in ST-segment elevation myocardial infarction (STEMI) patients with a concurrent chronic total occlusion (CTO).

Methods

In the randomized EXPLORE trial, there was no significant difference in global LV function after percutaneous coronary intervention (PCI) of the CTO, compared with no-CTO PCI, post-STEMI. In the current study, we included 200 of the 302 EXPLORE patients with a baseline CMR, of which 180 also had 4-month follow-up (serial) CMR. Global longitudinal strain (GLS) was calculated from 3 long-axis views. Global circumferential strain (GCS) and segmental strain were calculated from 3 short-axis views (basal, mid, and apical).

Results

Global strain significantly improved at 4 months (GLS ∆ − 1.8 ± 4.3%, p < 0.001; GCS ∆ − 1.7 ± 4.7%, p < 0.001); however, there was no treatment effect of CTO-PCI on strain recovery. GLS was a significant predictor for 4 months of LV ejection fraction (p = 0.006), incremental to other CMR parameters including infarct size. For mortality, infarct size remained the strongest predictor. On regional level, segmental strain independently predicted recovery in the dysfunctional segments (p < 0.001).

Conclusions

Global and segmental myocardial strains significantly improved over time, with no effect of CTO-PCI. Global strain was associated with outcome and segmental strain was an independent predictor for regional LV recovery in the dysfunctional CTO territory. Further research is needed to determine the additional prognostic value of strain beyond routine CMR parameters.

Key Points

• In STEMI patients with a concurrent CTO, strain significantly improves over time, regardless of CTO-PCI.

• Global strain is an independent predictor for functional recovery, incremental to infarct size, LVEF, and clinical parameters.

• Segmental strain was able to predict the recovery of wall thickening, incremental to transmural extent of infarction.

Electronic supplementary material

The online version of this article (10.1007/s00330-019-06338-x) contains supplementary material, which is available to authorized users.

Strain-encoded magnetic resonance: a method for the assessment of myocardial deformation

This study aims to assess the usefulness of strain‐encoded magnetic resonance (SENC) for the quantification of myocardial deformation (‘strain’) in healthy volunteers and for the diagnostic workup of patients with different cardiovascular pathologies. SENC was initially described in the year 2001. Since then, the SENC sequence has undergone several technical developments, aiming at the detection of strain during single‐heartbeat acquisitions (fast‐SENC). Experimental and clinical studies that used SENC and fast‐SENC or compared SENC with conventional cine or tagged magnetic resonance in phantoms, animals, healthy volunteers, or patients were systematically searched for in PubMed. Using ‘strain‐encoded magnetic resonance and SENC’ as keywords, three phantom and three animal studies were identified, along with 27 further clinical studies, involving 185 healthy subjects and 904 patients. SENC (i) enabled reproducible assessment of myocardial deformation in vitro, in animals and in healthy volunteers, (ii) showed high reproducibility and substantially lower time spent compared with conventional tagging, (iii) exhibited incremental value to standard cine imaging for the detection of inducible ischaemia and for the risk stratification of patients with ischaemic heart disease, and (iv) enabled the diagnostic classification of patients with transplant vasculopathy, cardiomyopathies, pulmonary hypertension, and diabetic heart disease. SENC has the potential to detect a wide range of myocardial diseases early, accurately, and without the need of contrast agent injection, possibly enabling the initiation of specific cardiac therapies during earlier disease stages. Its one‐heartbeat acquisition mode during free breathing results in shorter cardiovascular magnetic resonance protocols, making its implementation in the clinical realm promising.

Clinical applications of feature-tracking cardiac magnetic resonance imaging

Cardiovascular diseases represent the leading cause of mortality and morbidity in the western world. Assessment of cardiac function is pivotal for early diagnosis of primitive myocardial disorders, identification of cardiac involvement in systemic diseases, detection of drug-related cardiac toxicity as well as risk stratification and monitor of treatment effects in patients with heart failure of various etiology. Determination of ejection fraction with different imaging modalities currently represents the gold standard for evaluation of cardiac function. However, in the last few years, cardiovascular magnetic resonance feature tracking techniques has emerged as a more accurate tool for quantitative evaluation of cardiovascular function with several parameters including strain, strain-rate, torsion and mechanical dispersion. This imaging modality allows precise quantification of ventricular and atrial mechanics by directly evaluating myocardial fiber deformation. The purpose of this article is to review the basic principles, current clinical applications and future perspectives of cardiovascular magnetic resonance myocardial feature tracking, highlighting its prognostic implications.

Strain imaging using cardiac magnetic resonance

The objective assessments of left ventricular (LV) and right ventricular (RV) ejection fractions (EFs) are the main important tasks of routine cardiovascular magnetic resonance (CMR). Over the years, CMR has emerged as the reference standard for the evaluation of biventricular morphology and function. However, changes in EF may occur in the late stages of the majority of cardiac diseases, and being a measure of global function, it has limited sensitivity for identifying regional myocardial impairment. On the other hand, current wall motion evaluation is done on a subjective basis and subjective, qualitative analysis has a substantial error rate. In an attempt to better quantify global and regional LV function; several techniques, to assess myocardial deformation, have been developed, over the past years. The aim of this review is to provide a comprehensive compendium of all the CMR techniques to assess myocardial deformation parameters as well as the application in different clinical scenarios.

Value of three dimensional-speckle tracking imaging for predicting left ventricular function after non-ST-segment elevation myocardial infarction with percutaneous coronary intervention

BACKGROUND

Percutaneous coronary intervention (PCI) is the recommended treatment for high risk patients with non-ST-segment elevation myocardial infarction (NSTEMI).

OBJECTIVE

To investigate the application of three dimensional-speckle tracking imaging (3D-STI) on patients diagnosed with NSTEMI undergoing PCI.

METHODS

Forty-four NSTEMI patients and 20 healthy subjects that received basic clinical and laboratory examinations were included in our study. NSTEMI patients were divided into three groups: heart failure (HF) with normal ejection fraction (HF-NEF group, n = 19), heart failure with preserved ejection fraction (HF-PEF group, n = 14) and heart failure with a reduced ejection fraction (HF-REF group, n = 11). The global longitudinal peak systolic strain (GLS), global circumferential peak systolic strain (GCS), global radial peak systolic strain (GRS) and left ventricular (LV) torsion of all subjects were measured by 3D-STI before PCI and 1 month, 3 months after PCI. The high-sensitivity troponin T (hs-TNT), high-sensitivity C-reactive protein (hs-CRP) and N-terminal pro-brain natriuretic peptide (NT-pro BNP) were measured in each group. Correlations between these parameters and LV ejection fraction (LVEF) were tested by Pearson correlation analysis.

RESULTS

GLS, GCS and torsion were significantly decreased in the 3 NSTEMI groups compared with control group (P < 0.05). GLS, torsion were significantly improved in the three NSTEMI groups at postoperative 1 and 3 months (P < 0.05). HF-REF group showed improved GCS on postoperative 1 and 3 month compared with preoperative data, and improved GLS at 3-month follow-up compared with 1-month follow-up (P < 0.05). The hs-TNT, hs-CRP and NT-pro BNP increased in the three NSTEMI groups before PCI (P < 0.05), and decreased at postoperative 1 and 3 month (P < 0.05). LVEF has the positive correlations with LV endsystolic volume (LVESV) and torsion, as well as the negative correlations with LVGLS, LVGCS, NT-pro BNP (P < 0.05).

CONCLUSIONS

The combinative detection of 3D-STI and NT-pro BNP is an efficient way to assess the cardiac function in patients diagnosed with NSTEMI undergoing PCI.

Magnetic Resonance Imaging of Myocardial Strain After Acute ST-Segment-Elevation Myocardial Infarction: A Systematic Review

The purpose of this systematic review is to provide a clinically relevant, disease-based perspective on myocardial strain imaging in patients with acute myocardial infarction or stable ischemic heart disease. Cardiac magnetic resonance imaging uniquely integrates myocardial function with pathology. Therefore, this review focuses on strain imaging with cardiac magnetic resonance. We have specifically considered the relationships between left ventricular (LV) strain, infarct pathologies, and their associations with prognosis. A comprehensive literature review was conducted in accordance with the PRISMA guidelines. Publications were identified that (1) described the relationship between strain and infarct pathologies, (2) assessed the relationship between strain and subsequent LV outcomes, and (3) assessed the relationship between strain and health outcomes. In patients with acute myocardial infarction, circumferential strain predicts the recovery of LV systolic function in the longer term. The prognostic value of longitudinal strain is less certain. Strain differentiates between infarcted versus noninfarcted myocardium, even in patients with stable ischemic heart disease with preserved LV ejection fraction. Strain recovery is impaired in infarcted segments with intramyocardial hemorrhage or microvascular obstruction. There are practical limitations to measuring strain with cardiac magnetic resonance in the acute setting, and knowledge gaps, including the lack of data showing incremental value in clinical practice. Critically, studies of cardiac magnetic resonance strain imaging in patients with ischemic heart disease have been limited by sample size and design. Strain imaging has potential as a tool to assess for early or subclinical changes in LV function, and strain is now being included as a surrogate measure of outcome in therapeutic trials.