COMPARE: comparison of the effects of carvedilol CR and carvedilol IR on left ventricular ejection fraction in patients with heart failure.

Left ventricular ejection fraction (LVEF) is an important measure of ventricular function in the evaluation of heart failure. Immediate-release (IR) carvedilol twice daily has been shown to improve LVEF in subjects with ischemic and nonischemic chronic heart failure. A once-daily formulation, controlled-release (CR) carvedilol, is expected to improve quality of care through improved adherence as a result of the reduced frequency of dosing. This multicenter, randomized, double-blind study in subjects with stable chronic heart failure will compare the change in LVEF in patients receiving carvedilol IR with those receiving carvedilol CR. LVEF will be measured by 2-dimensional echocardiography at 6 months after entry into the maintenance period of the study drug. The secondary objectives of this study are to assess changes in left ventricular remodeling and function, to evaluate changes in brain natriuretic peptide levels, and to determine the incidence of all-cause and heart failure-related hospitalizations and all-cause mortality after treatment with carvedilol CR or carvedilol IR.