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 (<or=20 U), arrhythmia on Holter, left ventricular ejection fraction (LVEF<or=30%), and heart rate turbulence (HRT). Primary endpoint was total mortality. During a follow-up period of 22+/-5 months, 70 patients died. On multivariable analysis, prolonged QRS duration showed the highest association with total mortality (hazard ratio 4.0; CI 2.3-6.9) followed by HRT Category 2 (3.8; 2.0-7.3) and LVEF<or=30% (3.1; 1.7-5.6). The association of prolonged QRS duration and late mortality was particularly strong in patients with LVEF<or=30% (5.0; 1.8-14.1). On multivariable analysis of secondary endpoints, prolonged QRS duration was significantly associated with cardiac mortality (3.9; 1.9-7.8), but not with sudden death and serious arrhythmic events.
Conclusion: In the revascularization era, incidence of prolonged QRS duration is reduced. However, prolonged QRS duration is still highly correlated with increased late mortality.