- Significant cardiovascular disease, such as New York Heart Association cardiac disease (Class II or greater), myocardial infarction within the previous 3 months, unstable arrhythmias, or unstable angina. Patient with known coronary artery disease, congestive heart failure not meeting the above criteria, or known left ventricular ejection fraction less than 50% must be on a stable medical regimen that is optimized in the opinion of the treating physician