Cardiac magnetic resonance (CMR) identifies important prognostic variables in ischemic cardiomyopathy (ICM) patients such as left ventricular (LV) volumes, LV ejection fraction (LVEF), peri-infarct zone, and myocardial scar burden (MSB). It is unknown whether Doppler-based diastolic dysfunction (DDF) retains its prognostic value in ICM patients, in the context of current imaging, medical, and device therapies.Diastolic function was evaluated in ICM patients (LVEF ≤ 40% and ≥ 70% stenosis in ≥ 1 coronary artery) who underwent transthoracic echocardiogram and delayed hyperenhancement CMR studies within 7 days. The association of DDF with the combined end point was assessed after risk-adjustment using Cox proportional hazards models.A total of 360 patients with severe LV dysfunction (LVEF = 24 ± 9%) and extensive MSB (31 ± 17%) were evaluated; DDF was present in all patients (stage 1%-44%, stage 2%-25%, stage 3%-31%). There were 130 events (124 deaths and 6 heart transplants) over a median follow-up of 5.8 years (IQR, 3.7-7.4 years). On multivariable analysis, DDF > stage 1 (HR, 1.37; P = .007) was associated with the combined end-point, independent of clinical risk score (HR, 2.40; P < .0001), implantable cardioverter defibrillator implantation (HR, 0.60; P = .009), incomplete revascularization (HR, 1.32; P = .003), mitral regurgitation (HR, 3.37; P = .01), peri-infarct zone area (HR, 1.04; P = 0.02), and MSB (HR, 1.02; P = .01). DDF had incremental prognostic value for the combined end-point (model χ(2) increased from 89 to 95, P = .02).DDF is a powerful predictor of mortality in ICM patients with significant LV dysfunction, independent of clinical and CMR data. DDF assessment provides incremental value, improving risk stratification.