Clinical Implications of QRS Duration in Patients Hospitalized With Worsening Heart Failure and Reduced Left Ventricular Ejection Fraction

Abstract

Hospitalization for heart failure is associated with high postdischarge mortality and morbidity. The predictive value of the QRS duration during admission for heart failure has not been well studied. To investigate the predictive value of the QRS duration in patients hospitalized for heart failure with reduced left ventricular ejection fraction (LVEF). Retrospective, post hoc analysis from the Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study With Tolvaptan (EVEREST), an event-driven, randomized, double-blind, placebo-controlled study in patients hospitalized for heart failure and having an LVEF of 40% or less. A total of 4133 patients were enrolled at 359 North American, South American, and European sites between October 7, 2003, and February 3, 2006. After excluding 1029 patients with a pacemaker, implantable cardioverter-defibrillator, or both at enrollment and 142 patients without a reported baseline QRS duration, 2962 patients were included in the analysis: 1641 had a normal QRS duration (< 120 ms) and 1321 had a prolonged QRS duration (> or = 120 ms). Dual primary end points were all-cause mortality and the composite of cardiovascular death or hospitalization for heart failure. During a median follow-up of 9.9 months, all-cause mortality was 18.7% for patients with a normal baseline QRS duration and 28.1% for patients with a prolonged baseline QRS duration (hazard ratio [HR], 1.61; 95% confidence interval [CI], 1.38-1.87). The composite of cardiovascular death or hospitalization for heart failure was 32.4% for patients with a baseline QRS duration less than 120 ms and 41.6% for patients with a baseline QRS duration of 120 ms or greater (HR, 1.40; 95% CI, 1.24-1.58). The increased risk associated with prolonged QRS duration was confirmed after adjusting for multiple variables for all-cause mortality (HR, 1.24; 95% CI, 1.02-1.50) and the composite of cardiovascular death or hospitalization for heart failure (HR, 1.28; 95% CI, 1.10-1.49). Only 105 patients (3.6%) who presented with a prolonged baseline QRS duration had a normal QRS duration on their last inpatient electrocardiogram. A prolonged QRS duration appears common in patients with reduced LVEF who are hospitalized for heart failure and is an independent predictor of high postdischarge morbidity and mortality.