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.