Infarct characterization and quantification by delayed enhancement cardiac magnetic resonance imaging is a powerful independent and incremental predictor of mortality in patients with advanced ischemic cardiomyopathy.

Abstract

Infarct heterogeneity has been shown to be independently associated with adverse outcomes in previous smaller studies. However, it is unknown whether infarct characterization is an independent predictor of all-cause mortality in patients with advanced ischemic cardiomyopathy, after adjusting for clinical risk factors, severity of ischemic mitral regurgitation, incomplete revascularization, and device therapy. A total of 362 patients with ischemic cardiomyopathy (left ventricular dysfunction with >70% stenosis in ≥1 epicardial coronary artery) underwent delayed hyperenhancement-magnetic resonance imaging and coronary angiography between 2002 and 2006. Total myocardial scar and peri-infarct (PI) area were measured using various threshold techniques. Multivariate survival analysis (primary end point of all-cause mortality) was conducted. One hundred fifty-seven deaths occurred during a mean 5.4-year follow-up (mean left ventricular ejection fraction, 23±9%; mean end-systolic volume index, 113±48 mL; mean total myocardial scar %, 25.5±16.0%; mean PI%, 5.7±2.9%). PI% (β=2.07; P<0.001) was an independent predictor of survival, independent of age, end-systolic volume, sex, mitral regurgitation, diabetes mellitus, dyslipidemia, coronary artery disease severity, implantable cardioverter defibrillator, and incomplete revascularization. PI% using 2 to 3 SD technique yielded the highest incremental prognostic power (χ(2) score 149). In advanced ischemic cardiomyopathy, PI% is a powerful independent and incremental predictor of all-cause mortality. Infarct heterogeneity offers substantial further risk stratification when compared with quantification of total myocardial scar % alone even after adjusting for clinical risk factors, end-systolic volume index, mitral regurgitation, incomplete revascularization, and implantable cardioverter defibrillator implantation.