AIMS: To assess the association of prolonged QRS duration and late mortality in unselected post-infarction patients of the revascularization era. METHODS AND RESULTS: A total of 1455 survivors of acute myocardial infarction (MI) in sinus rhythm and under 76 years of age were enrolled. Ninety eight percent of the patients received reperfusion/revascularization therapy (90% percutaneous coronary intervention). After revascularization, prolonged QRS duration (>or=120 ms) was present in 87 patients (6.0%). Additional risk factors studied were age (>or=65 years), presence of diabetes mellitus, history of previous MI, mean heart rate (>75 b.p.m.), heart rate variability index (