Comparing warfarin with aspirin after biological aortic valve replacement: a prospective study.

BACKGROUND Patients with prosthetic heart valves have a higher risk of developing valve thrombosis and arterial thromboembolism. Antithrombotic therapy in the early postoperative period after biological aortic valve replacement (BAVR) is controversial. The American College of Cardiology/American Heart Association and European Society of Cardiology guidelines recommend the use of warfarin for the first 3 months after BAVR, although the American College Chest Physician guidelines suggest that the recommendations are very weak and that the risk/benefit is unclear. This prospective study investigated the efficacy of postoperative warfarin compared with aspirin in patients after aortic valve replacement. METHODS AND RESULTS Patients undergoing BAVR between 2001 and 2002 received 2 antithrombotic therapies: 141 patients received warfarin for the first 3 months, and 108 patients received only aspirin. The major end points evaluated were the rate of cerebral ischemic events, bleeding, and survival. There were 3 and 5 postoperative cerebral ischemic events between 24 hours and 3 months for patients treated with aspirin and warfarin, respectively. After 3 months, the incidence of cerebral ischemic events did not differ between the 2 groups. The rate of major bleeding events, the stroke-free survival, and the overall survival rates were not statistically significant between the warfarin and aspirin groups. CONCLUSIONS There seem to be no advantages in performing early anticoagulation therapy compared with a low-antiplatelet regimen with regard to early cerebral ischemic events, bleeding, and survival. Currently there is no evidence to support the fact that warfarin is more effective than aspirin.