Outcomes: The primary endpoint is a composite of all cause mortality and non-fatal heart failure events. Secondary endpoints include all-cause mortality, cardiovascular mortality (including classification in terms of suddenness and arrhythmic mechanism by prespecified Hinkle-Thaler criteria), non-fatal heart failure events, 6-minute walking test distance, quality of life, unplanned hospitalization, and ventricular arrhythmias requiring device therapy, inappropriate shocks, cardiovascular MRI prediction of response, percentage pacing and prediction of response to therapy, ventricular reverse remodeling.