MITRAL-VALVE CARPENTIER-EDWARDS BIOPROSTHETIC REPLACEMENT, THROMBOEMBOLISM, AND ANTICOAGULANTS

Patients undergoing mitral valve replacement (MVR) using a bioprosthes is are frequently placed on long-term anticoagulant treatment, and the reby lose the main advantage conferred by the bioprosthesis. To assess predictive factors of the need for long-term anticoagulant treatment, 100 consecutive patients surviving bioprosthetic MVR between 1977 and 1987 were followed up. The estimated thromboembolism-free survival wa s 88.9% +/- 3.6% after 6 years of follow-up. Preoperative risk factors for thromboembolism were supraventricular arrhythmia (p = 0.013) and a history of thromboembolism (p = 0.039). Among the preoperative and p ostoperative factors, only postoperative rhythm significantly influenc ed (p = 0.007) the thromboembolism-free survival, as determined by Cox regression analysis. Permanent anticoagulant treatment was instituted in 39 patients. Preoperative and peroperative risk factors associated with the need for long-term anticoagulant treatment, as evidenced by Fisher linear discriminant analysis, were supraventricular arrhythmia (p < 0.001), septal myotomy (p = 0.013), and predominant mitral stenos is (p = 0.013). Thus, in those patients with predominant mitral stenos is and supraventricular arrhythmia preoperatively, the subsequent need for permanent postoperative anticoagulant treatment is high, and the implantation of a mechanical valve is therefore recommended, providing there are no strict contraindications to anticoagulant treatment.