Patients hospitalized for heart failure who have a prolonged QRS complex appear to have a high risk for rehospitalization or death within a few months after discharge, according to an article in the June 11 issue of the Journal of the American Medical Association.

According to background information in the article, the frequency and predictive value of a prolonged QRS duration during an admission for heart failure have not been well studied. Establishing its prognostic value, if any, could help tailor therapy to improve post-discharge morbidity and mortality.

Mihai Gheorghiade, MD, and Norman C. Wang, MD, of the Northwestern University Feinberg School of Medicine, Chicago, and investigators with the Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study With Tolvaptan (EVEREST) trial, investigated the relationship of QRS duration and changes during the course of hospitalization to outcomes such as death and hospitalization for heart failure.

The study included 4,133 patients hospitalized for heart failure who had a left ventricular ejection fraction of 40 percent or less. After excluding 1,029 patients with a pacemaker, implantable cardioverter-defibrillator, or both at enrollment and 142 patients without a reported baseline QRS duration, 2,962 patients were included in the current analysis.

Of the 2,962 patents included in the current analysis, 1,641 had a normal QRS duration (less than 120 ms) and 1,321 had a prolonged QRS duration (120 ms or greater). Median follow-up time was 9.9 months.

There were 307 deaths (18.7 percent) among the 1,641 patients with a normal baseline QRS duration and 371 (28.1 percent) among the 1,321 patients with a prolonged baseline QRS duration.

The most common cause of death was heart failure followed by sudden cardiac death. The composite of cardiovascular death or hospitalization for heart failure was more frequent in patients with a prolonged baseline QRS duration at 3 months after enrollment (21.1 percent versus 14.6 percent) and at the end of the follow-up period of 9.9 months (41.6 percent versus 32.4 percent).

After adjusting for multiple variables, prolonged QRS duration during hospitalization was associated with a 24 percent increased risk of death and a 28 percent increased risk for the composite of cardiovascular death or rehospitalization for heart failure.

"In this analysis, a prolonged QRS duration was present in 45 percent of patients admitted with heart failure and reduced left ventricular ejection fraction, did not appear to significantly change during hospitalization, and was independently associated with high postdischarge mortality and readmission rate. This high morbidity and mortality was observed even though patients were well-treated with standard medical therapy that included beta-blockers and angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers," the authors wrote.

"Measurement of the QRS duration on an electrocardiogram has significant advantages as a tool in the clinical setting. It is relatively inexpensive, simple to perform, and yields an instant result. The measurement is objective and does not require specialized training to interpret. In addition, the QRS duration is stable in the majority of patients during the course of their hospitalization. Perhaps most important, a prolonged QRS duration becomes a potential target for intervention [with existing therapy], which may improve postdischarge mortality and morbidity."