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
Background—Infarct heterogeneity has been shown to be independently associated with adverse outcomes in previous smaller studies. However, it is unknown if infarct characterization is an independent predictor of all-cause mortality in patients with advanced ischemic cardiomyopathy (ICM), after adjusting for clinical risk factors, severity of ischemic mitral regurgitation, incomplete revascularization, and device therapy.
Methods and Results—A total of 362 patients with ICM (LV dysfunction with >70% stenosis in ≥1 epicardial coronary artery) underwent delayed hyperenhancement-MRI and coronary angiography between 2002 and 2006. Total myocardial scar (TMS) and peri-infarct (PI) area was measured utilizing various threshold techniques. Multivariate survival analysis, (primary end-point of all-cause mortality) was conducted. One hundred fifty-seven deaths occurred over a mean 5.4 year follow-up (mean LVEF 23±9%, mean ESVi 113±48 ml, mean TMS% 25.5±16.0%, mean PI% 5.7±2.9%. PI% (ß 2.07, p<0.001) was an independent predictor of survival, independent of age, end systolic volume, gender, mitral regurgitation, renal function, diabetes, dyslipidemia, coronary artery disease severity, implantable cardioverter defibrillator (ICD), and incomplete revascularization. PI% utilizing 2-3SD technique yielded the highest incremental prognostic power (χ2 score 149).
Conclusions—In advanced ICM, PI% is a powerful independent and incremental predictor of all-cause mortality. Infarct heterogeneity offers substantial further risk stratification compared to quantification of TMS% alone even after adjusting for clinical risk factors, end systolic volume index, mitral regurgitation, incomplete revascularization, and ICD implantation.
- Received February 20, 2014.
- Accepted July 18, 2014.