A comparative study of the St. Jude Medical and Björk-Shiley convexo-concave prostheses in isolated valve replacement
Aramendi, J.I.; Castellanos, E.; Serrano, A.; Madiedo, J.B.; Ortiz De Salazar, A.; Agosti, J.
Journal of Cardiovascular Surgery 32(5): 557-563
1991
ISSN/ISBN: 0021-9509 PMID: 1939315 Document Number: 381908
This is a study of 199 consecutive patients who survived isolated mitral or aortic valve replacement with a Bjork-Shiley (B-S) or St. Jude Medical (SJM) prostheses. Mean follow-up was 36 months. Preoperative status was similar for both groups (B-S or SMJ). Five year survival rates for mitral valve replacement (MVR) were 91% for B-S and SJM, and for aortic valve replacement (AVR) 96% vs 91% for SJM (p < 0.06). Linearized incidence of thromboembolism in MVR was 5.62% patient year for BS and 5.23% patient year for SJM (p = NS). Classical risk factors for thromboembolism were evaluated on a univariate analysis: no single risk factor was identified. Only the association of two or more was possibly significant. The presence of inadequate anticoagulation (prothrombin index > 50%) was the main risk factor for thromboembolism, as the incidence rate was 19% per patient year when poorly anticoagulated versus 4.6% per patient year incidence in the whole series (p < 0.01).