Biological valves beyond fifteen years: The wessex experience

Between 1975 and 1979, 443 biological valves (298 Carpentier-Edwards, 134 homograft, and 11 Hancock valves) were implanted in 415 patients (age, 16 to 77 years; mean, 59 years) with an operative mortality of 2.9%. Total follow-up was 4,248 patient-years. Overall event-free survival was 60% ± 1.5% (standard deviation) at 10 years and 29% ± 1.4% at 15 years. Ten-year and 15-year event-free survival were 72% ± 3.4% and 41% ± 3.3% for aortic homografts, 62% ± 3% and 33% ± 2.8% for isolated aortic xenografts, and 43% ± 3.5% and 14% ±3.0% for isolated mitral xenografts. Freedom from structural valve degeneration was 87% ± 1.3% and 63% ± 2.5% for all patients at 10 and 15 years, respectively, 86% ± 2.7% and 58% ± 4.1% for aortic homografts, 93% ± 1.8% and 76% ± 5.1% for aortic xenografts, and 75% ± 4.0% and 47% ± 7.4% for mitral xenografts. Of the 110 remaining patients, echocardiography was performed in 61 patients (23 aortic xenograft, 24 aortic homograft, 9 mitral xenograft, and 5 tricuspid xenograft) between 14 and 17 years after implantation. An early diastolic murmur was heard in 57% of all aortic valve replacements (AVRs) 62.5% of homograft AVRs, and 52% of xenograft AVRs. Echocardiographically, aortic regurgitation was detected in 79%, 83%, and 74% of all AVRs, homografts, and xenografts, respectively. Aortic stenosis was present clinically in 11% of all AVRs, 4% of homograft AVRs, and 17% of xenograft AVRs. For all AVRs, homograft AVRs, and xenograft AVRs, the peak aortic valve gradient was 22.68 ± 2.38 mm Hg, 18.37 ± 10.6 mm Hg, and 27.23 ± 12.7 mm Hg (p < 0.01 for homograft versus xenograft); the estimated aortic valve area was 1.44 ± 0.6 cm2, 1.76 ± 0.55 cm2, and 1.09 ± 0.43 cm2. Of the 9 mitral patients none had an estimated mitral valve area less than 1 cm2. Five patients had mitral regurgitation detected on echocardiography; in 4 of these a pansystolic murmur was audible. Bioprosthetic valves have acceptable long-term hemodynamic and performance profiles up to 15 years, making them an excellent alternative in patients unsuitable for anticoagulation.