- Unstable angina or myocardial infarction within 4 months prior to randomization, New York Heart Association (NYHA) class III or IV heart failure, left ventricular ejection fraction (LVEF) < 40%, uncontrolled angina, history of severe coronary artery disease, severe uncontrolled ventricular arrhythmias including uncontrolled chronic atrial fibrillation/atrial flutter, history of torsades de pointe, sick sinus syndrome, or electrocardiographic evidence of acute ischemia or grade 3 conduction system abnormalities unless subject has a pacemaker