QRS duration is of prognostic relevance in patients with several underlying heart diseases. Short-term data also show the prognostic value of QRS duration in lower risk groups of patients. The aim of this study was to investigate the long-term prognostic value of QRS duration in patients with known or suspected coronary artery disease. The study cohort consisted of 512 patients (308 men, mean age 60 +/- 11 years) who underwent myocardial perfusion imaging (MPI) for the evaluation of suspected or known coronary artery disease. Follow-up data were collected to assess the prognostic value of QRS duration, alongside clinical characteristics and MPI results. End points were cardiac death and cardiac death or nonfatal myocardial infarction (MI). During a mean follow-up of 8.6 +/- 5.2 years, 290 patients (60%) died, with 139 deaths (27%) attributable to cardiac causes. Nonfatal MI occurred in 28 patients (6%), and 127 patients (25%) underwent late coronary revascularization (>3 months). Patients with QRS duration <120 ms had annualized cardiac death rates and cardiac death or nonfatal MI rates of 2.2% and 2.3%, respectively, compared with those of 4.1% and 4.4% in patients with QRS duration >= 120 ms. Multivariate models identified QRS duration >= 120 ms as an independent predictor of both end points, on top of clinical characteristics and MPI results. In conclusion, QRS duration >= 120 ms is an independent predictor of cardiac death and cardiac death or nonfatal MI, after adjustment for clinical characteristics and MPI results. (C) 2015 Elsevier Inc. All rights reserved.