- History of cardiac disease, including congestive heart failure of New York Heart Association (NYHA) class >II, unstable angina (anginal symptoms at rest) or new-onset angina (within 6 months prior to study entry), myocardial infarction within 6 months prior to study entry, or cardiac arrhythmias requiring anti-arrhythmic therapy except for beta-blockers and digoxin; evidence for uncontrolled coronary artery disease (e.g. angina pectoris, myocardial infarction within 6 months prior to study entry, major regional wall motion abnormalities upon baseline echocardiography or multiple-gated acquisition [MUGA] scan). Patients with a pacemaker are also excluded