- History of cardiac disease: congestive heart failure New York Heart Association (NYHA) class > II, unstable angina (anginal symptoms at rest), new-onset angina (within the past 3 months before study entry), myocardial infarction within the past 3 months before study entry, or cardiac arrhythmias requiring anti-arrhythmic therapy (beta blockers, calcium channel blockers, and digoxin are permitted)