Isolated aortic valve replacement with the Björk-Shiley tilting disc prosthesis and the porcine bioprosthesis

Between 1977 and 1978, 239 patients underwent aortic valve replacement with either a bioprosthesis (100, BIO) or a Björk-Shiley tilling disc prosthesis (139, BS). Early mortality was 2%, late mortality 4%. There was no statistically significant difference between the two groups. Anticoagulation was maintained indefinitively in patients with a BS, after implantation of a BIO only for three months except in the presence of atrial fibrillation or a history ofeinboli. Thromboembolic complications and anticoagulant hemorrhages were almost twice as frequent in patients with BS than with BIO (5.3 versus 2.8 episodes/100 patient years). This difference however is statistically not significant. There were an equal number (two) of reoperations because of paravalvular leaks due to endocarditis or torn sutures in the two groups. A regurgitant murmur, though hemodynamically not significant, occurred more frequently in patients with BIO than with BS (10% versus 2%, P < 0.05). Its cause and importance cannot yet be determined. Postoperative results judged by the NYHA classification and reduction of heart size were similar in both groups. Of all patients, 13% with preoperative valvular incompetence and 15% with stenosis showed little or no reduction of the cardiothoracic ratio on X-ray indicating a worse long-term prognosis. The porcine BIO has become our preferred valvular substitute because of its low thromboembolic complication rate. The BS is mainly reserved for patients already on anticoagulants for other reaso