Over twenty-year follow-up of the standard Hancock porcine bioprosthesis implanted in the mitral position

Abstract

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.