Repeated thromboembolic and bleeding events after mechanical aortic valve replacement

Background. The choice of a valve substitute in young adults requires a dec ision balancing the risks of longterm anticoagulation versus reoperation(s) . This article analyzes the long-term risk and determinants of thromboembol ic (TE) and bleeding (BLE) complications after mechanical aortic valve repl acement (AVR). Methods. From December 1963 to January 1974, 249 patients survived a mechan ical AVR at our institution. Mean age was 41.8 +/- 12.4 years and 81% (n = 202) were male. Ball valves were implanted in 24% (n = 61) and disc valves in 76% (n = 188). Patients were anticoagulated with vitamin K antagonists a nd dipyridamole. A total of 4,855 patient-years was available for analysis. Mean follow-up was 19.5 +/- 9.4 years and was 100% complete. Analyses were performed with Kaplan-Meier and multivariable Cox regression methods. Results. One hundred and two patients had one TE or BLE postoperative event and 58 patients had two postoperative events. Six patients had more than f ive postoperative events. Freedom from a first postoperative event was 74.8 % +/- 2.9%, 55.3% +/- 3.5%, and 46.8% +/- 4.0% at 10, 20, and 30 years, res pectively. Freedom from a second postoperative event was 45.4% +/- 5.4%, 29 % +/- 6.0%, and 23.2% +/- 7.1% at 10, 20, and 30 years, respectively. Multi variate predictors for TE or BLE complications were ball valve (Odds Ratio (OR) = 2.9), postoperative endocarditis (OR = 2.2), and any surgery (OR = 2 .2). The incidence of events was highest the first 5 postoperative years. Conclusions. The risk of adverse events is highest the first 5 postoperativ e years. Once an event has occurred, the risk for a second event is increas ed. The incidence and frequency of events is substantial and should be cons idered in the choice of a valve substitute. (C) 2001 by The Society of Thor acic Surgeons.