Study Comparing Desirudin With Heparin to Prevent Vein Clots After Heart and Lung Surgery

Patients who are randomized to the desirudin (study) group will receive 15 mg of subcutaneous desirudin twice a day (at 0900 and 2100). These patients will also receive an injection of normal saline placebo at 1300 so that patients in both groups will receive three injections at the same time points.

The patients who are randomized to the Heparin (standard of care) group will receive subcutaneous injections of heparin three times a day (0900, 1300 and 2100).