Prognostic Value of Myocardial Viability by Delayed Enhanced MR in Patients with Coronary Artery Disease and Low Ejection Fraction. Impact of Revascularization Therapy

Gerber, Bernhard [UCL] Rousseau, Michel [UCL] Ahn, Sylvie [UCL] Le Polain De Waroux, Jean-Benoît [UCL] Pouleur, Anne-Catherine [UCL] Vancraeynest, David [UCL] Pasquet, Agnes [UCL] Vanoverschelde, Jean-Louis [UCL]

Background. Prior works showed that delayed-enhanced cardiac magnetic resonance (DE-cMR) predicts recovery of left ventricular dysfunction (LVD) after revascularization in coronary artery disease (CAD). We sought to evaluate impact of myocardial viability assessment by DE-cMR and of revascularization therapy on survival of patients (pts) with low ejection fraction (EF). Methods and Results. We prospectively evaluated survival of 144 consecutive pts (130 males, 65±11 years) with CAD and LVD (EF 24±7%) undergoing DE-cMR. 86 pts underwent complete revascularization of dysfunctional myocardium (79 CABG, 7 PCI), while 58 pts remained under medical treatment. Pts were considered to have viable myocardium if >4 dysfunctional segments had <50% transmurality of DE. Over 3-years median follow-up 49 pts died. 3-year survival was significantly worse in pts with dysfunctional viable myocardium remaining under medical treatment (48%) than in medically treated pts with non-viable myocardium (77%, p=0.02 by log-rank test). By contrast, in revascularized pts, survival was similar whether myocardium was viable or not (88 and 71% survival respectively, p=NS). Hazard of death of medically treated viable myocardium was 4.56 [95% CI 1.93-10.8]. Cox multivariate analysis indicated that interaction of revascularization and viability provided significant additional value (X2=13.1, p=.004) to baseline predictors of survival (NYHA class, wall motion score and peripheral arterial disease). More importantly, in 43 pairs of propensity score matched pts for treatment selection, hazard of death (2.5 [95% CI 1.1-6.1, p=0.02]) remained significantly higher for medically treated rather than revascularized viable myocardium (Figure). Conclusions. Without revascularization, presence of viable myocardium by DE-cMR is an independent predictor of mortality in pts with ischemic LVD. This observation may be useful for preoperative selection of pts for revascularization.