Myocardial Viability Assessment in Ischemic Left Ventricular Dysfunction: Insights from Cardiac Magnetic Resonance Imaging

BACKGROUND Ischemic cardiomyopathy (ICM) is the leading cause of heart failure with reduced ejection fraction (HFrEF). The role of myocardial viability, as assessed by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR), remains controversial when used to guide decision-making for revascularization. MATERIALS AND METHODS This is a retrospective observational single-centre study on all consecutive patients with a LVEF ≤ 35% and significant coronary artery disease undergoing CMR imaging for viability assessment before coronary intervention. Myocardial viability was defined as the presence of ≥4 dysfunctional segments without the presence of transmural scarring (< 50% LGE transmurality). The primary endpoint was all-cause mortality; secondary endpoint was improvement in left ventricular ejection fraction (LVEF). RESULTS Of the 111 patients (89% males, mean age 66 (62 - 75)) enrolled, 87 (78%) had CMR evidence of myocardial viability before treatment. 67 patients (60%) underwent revascularization procedures. Over a median follow-up of 37 months, 36 (32%) patients died. Mortality rate was significantly lower for patients undergoing revascularization compared to those who did not (25% vs. 43%, p = 0.048). Age (p = 0.037) and systemic hypertension (p = 0.046) were identified as independent predictors of mortality. Myocardial viability was not associated with improved survival (log-rank p = 0.853). Improvement in LVEF was observed more frequently in patients with myocardial viability, irrespective of the treatment strategy adopted (OR 5,1; IC 1,52-17,5; p= 0,008); however, this improvement was not associated with longer survival (log-rank p = 0,617). CONCLUSION In this cohort of patients with severe ischemic LV dysfunction, myocardial viability assessment did not identify those who derive greater benefit from revascularization. Further studies are needed to evaluate alternative strategies for assessing myocardial viability in this specific patient population.