12. Renal dysfunction defined be serum creatinine levels higher or equal to 1.8 mg%, 13. Abnormal liver function tests 14. Uncontrolled diabetes mellitus, 15. Severe peripheral vascular disease 16. Prior cerebrovascular neurological event. 17. Abnormal left or right ventricular function. 18. Treatment with warfarin or thienopyridine class of anti-platelet agents. 4.2.3 Withdrawal Criteria Patients will preserve the right to withdraw from the study at any time during treatment without prejudice.