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.