Comparison of myocardial infarct size assessed with contrast-enhanced magnetic resonance imaging and left ventricular function and volumes to predict mortality in patients with healed myocardial infarction

Abstract

Currently, left ventricular (LV) ejection fraction (EF) and/or LV volumes are the established predictors of mortality in patients with coronary artery disease (CAD) and severe LV dysfunction. With contrast-enhanced magnetic resonance imaging (MRI), precise delineation of infarct size is now possible. The relative merits of LVEF/LV volumes and infarct size to predict long-term outcome are unknown. The purpose of this study was to determine the predictive value of infarct size assessed with contrast-enhanced MRI relative to LVEF and LV volumes for long-term survival in patients with healed myocardial infarction. Cine MRI and contrast-enhanced MRI were performed in 231 patients with healed myocardial infarction. LVEF and LV volumes were measured and infarct size was derived from contrast-enhanced MRI. Nineteen patients (8.2%) died during a median follow-up of 1.7 years (interquartile range 1.1 to 2.9). Cox proportional hazards analysis revealed that infarct size defined as spatial extent (hazard ratio [HR] 1.3, 95% confidence interval [CI] 1.1 to 1.6, chi-square 6.7, p=0.010), transmurality (HR 1.5, 95% CI 1.1 to 1.9, chi-square 8.9, p=0.003), or total scar score (HR 6.2, 95% CI 1.7 to 23, chi-square 7.4, p=0.006) were stronger predictors of all-cause mortality than LVEF and LV volumes. In conclusion, infarct size on contrast-enhanced MRI may be superior to LVEF and LV volumes for predicting long-term mortality in patients with healed myocardial infarction.