17. Any of the following concurrent severe and/or uncontrolled medical conditions which could compromise participation in the study: New York Heart Association (NYHA) >/= grade 2 congestive heart failure; Myocardial infarction within 6 months of study enrollment; History of stroke within 6 months of study enrollment; Unstable symptomatic arrhythmia requiring medication (Patients with chronic atrial arrhythmia, i.e., atrial fibrillation or paroxysmal SVT are eligible); Clinically significant peripheral vascular disease; Uncontrolled diabetes; Serious active or uncontrolled infection