MITRAL-VALVE REPLACEMENT WITH THE ST-JUDE-MEDICAL PROSTHESIS - A 15-YEAR FOLLOW-UP

Background. A retrospective study was conducted to analyze the results of St. Jude Medical mitral valve replacement. Methods. From January 1 979 to December 1989, 870 patients (54%:, women, 46% men; mean age, 55 .8 +/- 6.2 years) underwent mitral valve replacement with the St. Jude Medical prosthesis. Of these operations 616 were isolated mitral valv e replacements and 254 were double valve replacements. Coronary artery bypass grafting was performed concomitantly in 55 patients (6.3%). Re sults. Overall, early mortality was 5.05%, with 4.2% for the isolated mitral valve procedure and 7.08% for the double valve replacement. Fol low-up at 15 years was complete in 859 patients (98.74%). Mean follow- up time was 93.5 months, for a total of 6,436 years. Actuarial surviva l at 15 years was 59.5% +/- 5%, 60.5% +/- 6%, and 56.9% +/- 9%, for th e entire group, the isolated mitral valve and double valve procedures, respectively. Multivariate analysis identified age, sex, hospital sta y, and preoperative mitral regurgitation as independent prognosis fact ors for overall mortality. Of 606 patients alive at the latest follow- up, the New York Heart Association class improved significantly (from 67% class III/IV before the operation to 88% class I/II after the oper ation). All patients received warfarin to maintain an international no rmalized ratio between 3.5 and 4. The linearized rates (% per patient- year) of thrombosis, thromboembolism, and major hemorrhage were, respe ctively, 0.21, 0.75, and 0.94 for the entire group; 0.18, 0.67, and 0. 58 for the isolated mitral valve operation; and 0.15, 0.92, and 1.08 f or the double valve replacement. For the entire group the freedom from thrombosis and thromboembolism at 15 years was 98.1% +/- 1% and 88% /- 4%, respectively. No case of structural dysfunction occurred. The f reedom from paravalvular leak and endocarditis at 15 years was 95.3% /- 2% and 97.3% +/- 2.4%, respectively. The probability of remaining f ree from reoperation at 15 years was therefore 95.6% +/- 2.5%. Conclus ions. These results confirm that the St. Jude Medical valve is a relia ble prosthesis with very low thrombosis and thromboembolism rates, all owing the use of a low dose of anticoagulation with an international n ormalized ratio of about 3. (Ann Thorac Surg 1998;66:762-7) (C) 1998 b y The Society of Thoracic Surgeons.