Background and aim of the study: The long-term (18 years) results after aortic (AVR), mitral (MVR) and double (aortic/mitral, DVR) valve replacement with Hancock II bioprosthesis were investigated.
Methods: Between 1978 and 1996, 279 Hancock II bioprostheses were implanted in 269 patients (166 males, 113 females; mean age 61.8+/-13.3 years). There were 135 AVR (48.4%), 122 MVR (43.8%) and 22 DVR (7.8%). Preoperatively, 208 patients (77.3%) were in NYHA functional class III/IV, 53 (19.7%) had previous cardiac surgery, and 19 (7.1%) underwent concomitant coronary artery bypass. Follow up (mean seven years) was 96% complete, with a total of 1,857 patient-years.
Results: There were 20 early (7.3%), and 78 (29.0%) late deaths. At the last follow up, 68.3% of patients were in NYHA functional class I/II. The actuarial survival rate of patients at 10 and 18 years after discharge was 67.7+/-5.0% and 44.7+/-8.8% after AVR and 64.5+/-5.6% and 32.7+/-11.5% after MVR, respectively; survival after DVR was 74.0+/-11.2% at 12 years. At 10 and 18 years, actuarial freedom from thromboembolism was 83.5+/-4.5% and 73.1+/-10.5% after AVR and 82.1+/-4.3% and 73.2+/-7.3% after MVR; it was 78.4+/-15.0% after DVR at 12 years. At these times, actuarial freedom from hemorrhage was 88.7+/-3.8% and 83.5+/-6.2% after AVR and 79.0+/-4.9% and 32.6+/-23.3% after MVR; freedom after DVR was 36.2+/-26.6%. Probability of freedom from endocarditis at 10 and >15 years was 93.4+/-3.5% and 85.9+/-7.8% after AVR and 97.0+/-2.1% and 97.0+/-2.1% for MVR, respectively; freedom at 10 years after DVR was 75.0+/-21.6%. Freedom from structural deterioration at 10 and 18 years was 77.9+/-5.3% and 18.7+/-14.6% after AVR and 78.3+/-6.0% and 32.1+/-10.2% after MVR; freedom at 10 and 12 years after DVR was 64.0+/-17.5% and 32.0+/-24.2%. A low incidence of structural valve deterioration was found in AVR patients aged >65 years (p = 0.0478). Hemorrhage and paravalvular leak were more frequent in MVR (p = 0.0296 and 0.0309, respectively). No difference was seen in thromboembolism after anticoagulation for one or three months after AVR. Actuarial freedom from explantation at 10 and 18 years was 73.1+/-5.9% and 15.9+/-13.5% after AVR and 77.1+/-6.1% and 37.3+/-9.7% after MVR; freedom at 10 and 12 years after DVR was 72.0+/-17.8% and 24.0+/-20.4%.
Conclusion: Over an 18-year follow up, the Hancock II bioprosthesis has shown satisfactory results, with a low incidence of valve-related complications, especially in elderly patients in the aortic position.