A Study to Compare the Effects of Coreg CR and Coreg IR on Heart Function in Subjects With Stable Chronic Heart Failure

Inclusion Criteria: * Male or non-pregnant female * At least 18 years of age at the time informed consent is signed * Stable, chronic, mild to severe heart failure as defined as subjects with symptoms of heart failure who do not require IV diuretics, inotropes, or vasodilators or those that require support with a left ventricular assist device * Angiotensin converting enzyme inhibitors or angiotensin receptor blockers should be prescribed to all patients with HF due to LV systolic dysfunction with reduced LVEF unless contraindicated or intolerant to use * At screening, subject has an LVEF \< 40 as measured by 2-D echocardiography * Willing to provide written informed consent Exclusion Criteria: * On beta-blocker therapy for greater than 42 days prior to consent * Acute ischemic coronary event or coronary revascularization (PTCA, CABG, thrombolysis) within 1 week of screening echocardiography * Scheduled or expected to be scheduled coronary revascularization within 4 weeks * Unstable angina (angina characterized by sudden changes in the severity or length of angina attacks or a decrease in level of exertion that precipitates an episode * Uncorrected primary obstructive or severe regurgitant valvular disease, nondilated (restrictive) or hypertrophic cardiomyopathies * Uncontrolled ventricular arrhythmias (symptomatic or sustained ventricular arrhythmias not controlled with antiarrhythmic therapy or an implantable defibrillator) * Current treatment of calcium channel blockers…