QRS duration and late mortality in unselected post-infarction patients of the revascularization era

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 (≥120 ms) was present in 87 patients (6.0%). Additional risk factors studied were age (≥65 years), presence of diabetes mellitus, history of previous MI, mean heart rate (>75 b.p.m.), heart rate variability index (≤20 U), arrhythmia on Holter, left ventricular ejection fraction (LVEF≤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≤30% (3.1; 1.7–5.6). The association of prolonged QRS duration and late mortality was particularly strong in patients with LVEF≤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.