16. Significant cardiovascular disease (New York Heart Association Class II or greater), myocardial infarction within the 6 months prior to study entry, unstable angina, or cerebral vascular accident / stroke (< 6 months prior to enrollment), or serious uncontrolled cardiac arrhythmia requiring medication / active intervention, corrected QT interval [QTc] prolongation of > 470ms and/or prior diagnosis of congenital long QT syndrome.