Over twenty-year follow-up of the standard Hancock porcine bioprosthesis implanted in the mitral position.
BACKGROUND: To define the long-term results of 331 standard Hancock porcine bioprostheses implanted in the mitral position between 1973 and 1980. METHODS: Of 331 patients (225 male patients, 68%), mean age 49+/-10 years (range 14 to 69 years), 88% were in New York Heart Association functional class III or IV and 77% were in atrial fibrillation. Follow-up time extended more than 20 years (mean 13.9 years, range 0.3 to 24.7 years) for a total of 4,601 patient-years. RESULTS: Overall operative mortality was 6.3%. At 5, 10, 15, and 20 years, the actuarial survival rate of patients were 71%+/-2%, 46%+/-3%, 30%+/-3%, and 22%+/-2%, respectively. Actuarial estimates of freedom from structural valve deterioration were 95%+/-1%, 67%+/-3%, 32%+/-3%, and 14%+/-3%; from reoperation were 96%+/-1%, 72%+/-3%, 36%+/-4%, and 18%+/-4%; from thromboembolism were 89%+/-2%, 82%+/-3%, 74%+/-4%, and 51%+/-2%; and from anticoagulant-related hemorrhage were 98%+/-1%, 96%+/-1%, 91%+/-1%, and 86%+/-4%. Estimates of freedom from all valve-related mortality at 5, 10, 15, and 20 years were 89%+/-2%, 76%+/-3%, 64%+/-4%, and 48%+/-4%. Multivariate analysis showed younger age to be a significant risk factor for reoperation. Age at operation did not correlate with structural valve deterioration. CONCLUSIONS: The long-term results with the standard Hancock bioprosthesis implanted in the mitral position appear satisfactory, particularly up to 15 years from implantation. Protection from stroke, anticoagulant hemorrhage, and endocarditis was good.