Anticoagulation is unnecessary after biological aortic valve replacement

Opinion differs as to whether anticoagulation is beneficial in preventing ischemic stroke in the early postoperative period after biological aortic valve replacement (AVR). The purpose of this study was to determine whether early anticoagulation with heparin and warfarin confers any significant advantage for patients undergoing such replacement.

Patients undergoing biological AVR between 1987 and 1996 were divided retrospectively into 2 groups based on their postoperative anticoagulation. Group A (109 patients) received heparin followed by warfarin for 3 months (prothrombin time, 20 to 25 seconds). Group B (76 patients) received no postoperative anticoagulation. Patients were followed for cerebral ischemic events, bleeding, repeat operation, hospital stay, and survival. There were 5 (4.6%), 3 (2.8%), and 12 (11%) postoperative cerebral ischemic events for group A at time points of < 24 hours, 24 hours to 3 months, and > 3 months, respectively; for group B patients, 3 (3.9%), 2 (2.6%), and 9 (11.8%) events were seen during the same respective time periods. There were no statistically significant differences for ischemic events during any of these time periods for the 2 groups. Bleeding complications occurred in 10 (9.2%) group A and 7 (9.2%) group B patients. Mean hospital stay was 12 days for both groups. Repeat operative AVR was required in 6 (5.5%) group A and 7 (9.2%) group B patients. A comparison of Kaplan-Meier survival rates between groups A and B (mean follow-up, 47 +/- 26 and 59 +/- 30 months, for groups A and B, respectively) was not statistically significant (P = 0.60). Survival rates were 93%, 84%, and 62% at 1, 5, and 7 years for group A and 87%, 74%, and 67% for group B, respectively.

Early anticoagulation after AVR confers no advantage in the prevention of early cerebral ischemic events after biological AVR. No disadvantage in terms of bleeding or prolonged hospital stay was incurred by early anticoagulation. Long-term valve function and survival were not adversely affected by withholding early anticoagulation. We conclude that early anticoagulation after biological AVR is unnecessary.