Antiplatelet therapy in patients receiving aortic bioprostheses: A report of clinical and instrumental safety

Objective: The main advantage of bioprostheses, avoidance of anticoagulant therapy, is compromised during the early postoperative period; in fact, warfarin is often administered during the first 3 postoperative months. Methods: We analyzed 250 patients undergoing tissue aortic valve replacement between January 2002 and December 2005. The patients received either aspirin (group 1) or oral anticoagulation (group 2) during the first 3 months. In a subgroup of these patients, we investigated the possible presence of clinically silent microembolization by means of transcranial Doppler for microembolic signal detection. Results: Thirty-day mortality was 0%. No major neurologic events occurred. Two episodes of bleeding were observed in both groups. Follow-up time was 24 +/- 14 months. Overall late mortality rate was 0.8% in group 1 versus 12% (mainly cancer related) in group 2. In group 2, 2 deaths were due to major ischemic neurologic events; overall, 3 major neurologic episodes occurred (international normalized ratio was within therapeutic range). There were no neurologic events in group 1 (P = .12). Stroke-free Survival did not reach statistical significance between the 2 groups. Transcranial Doppler was performed after a mean interval of 55 +/- 19 days, with no detection of microembolic signals in patients receiving either aspirin or warfarin. There were no episodes of bleeding or neurologic events. Conclusions: Aspirin therapy appears to be the appropriate response to both cardiac Surgeons' and patients' needs in the early postoperative course after aortic valve replacement with tissue valves, demonstrating adequate antithromboembolic efficacy with no added risk for bleeding as well as ease of administration.