QRS Duration and Mortality in Congestive Heart Failure Patients
Background and Objectives: It has been suggested that prolongation of the QRS duration (>120 ms) is an independent risk factor for mortality in patients with cardiomyopathy. The purpose of this study was to examine the association between QRS duration and survival in patients with heart failure.
Methods: We performed a retrospective analysis to examine the association between QRS prolongation (≥120 ms) and mortality. The study population included 669 patients with heart failure. Two groups, on the basis of baseline QRS duration ≤120 milliseconds or ≥120 milliseconds, were identified. The groups were compared with respect to total mortality and sudden death. Subgroups were also stratified by right bundle branch block and left bundle branch block, ejection fraction (EF) ≤30% and ≥30% to 40%, ischemic and nonischemic cardiomyopathy, amiodarone and placebo.
Results: Prolonged QRS was associated with a significant increase in mortality (49.3% vs 34.0%, P = .0001) and sudden death (24.8% vs 17.4%, P = .0004). Left bundle branch block was associated with worse survival (P = .006) but not sudden death. In patients with an EF ≤30%, QRS prolongation continued to be associated with a significant increase in mortality (51.6% vs 41.1%, P = .01) and sudden death (28.8% vs 21.1%, P = .02). In those with an EF of 30% to 40%, QRS prolongation was associated with a significant increase in mortality (42.7% vs 23.3%, P = .0036) but not in sudden death (13.3% vs 12.0%, P = .625). After adjustment for baseline variables, independent predictors of mortality were found to be prolongation of QRS (P = .0028, risk ratio 1.46) and depressed EF (P = .0001, risk ratio 0.965). Age, type of cardiomyopathy, and drug treatment group were not predictive of mortality.
Conclusion: QRS prolongation is an independent predictor of both increased total mortality and sudden death in patients with heart failure.

Congestive heart failure is a common condition affecting 1% of adults in the United States. It contributes to 250,000 deaths and over 700,000 hospitalizations per year in the United States, with annual expenditures exceeding 10 billion dollars. Despite

-blockers, spironolactone, angiotensin-converting enzyme inhibitors, and antiarrhythmic devices, the prognosis is poor. Predictors of death that have been evaluated include reduced left ventricular ejection fraction, abnormal signal-averaged electrocardiography, presence of nonsustained ventricular tachycardia, low heart rate variability, increased Q-T dispersion, and presence of T-wave alternans. As a result, investigators have examined the significance of QRS prolongation as a noninvasive predictor of increased mortality. A QRS duration >120 milliseconds has been shown to have a 99% specificity for left ventricular (LV) dysfunction and may be a potent marker for adverse outcome. We sought to clarify the association between QRS duration and mortality in patients participating in the randomized, prospective, placebo-controlled trial of Congestive Heart Failure Survival Trial of Antiarrhythmic Therapy (CHF-STAT).