Carpentier-Edwards porcine bioprostheses: Clinical performance assessed byactual analysis

Background and aim of the study: The clinical performance of porcine biopro stheses for valve replacement has been evaluated for over three decades by actuarial analysis as the standard for reporting time-related results. Actu al or cumulative incidence analysis provides a complementary method to dete rmine the manifestations of valve-related complications due primarily to st ructural valve deterioration. Valve-related mortality and reoperation of po rcine bioprostheses for aortic and mitral valve replacement was compared by actuarial and actual methodology. Methods: The Carpentier-Edwards porcine bioprostheses were implanted betwee n 1975 and 1995 as 2,237 aortic valve replacements (AVR) and 1,582 mitral v alve replacements (MVR). Coronary artery bypass was performed in 36.4% of A VR, and 30.6% of MVR. Fatal valve-related complications occurred in 7.6% of AVR and 11.3% of MVR. The cumulative follow up was 14,810 patient-years (m ean 6.6 years) for AVR and 9,718 patient-years (mean 6.1 years) for MVR. Results: Patient survival, and actuarial and actual freedom from valve-rela ted mortality and valve-related reoperation was reported at 15 years. For A VR, survival in the 61-70 years age group was 30.9%, freedom from valve-rel ated mortality was 79.3% and 86.9% respectively, and freedom from valve-rel ated reoperation 79.0% and 88.1% respectively. For AVR, survival in the >70 years age group was 18.1%, freedom from valve-related mortality 72.8% and 84.9% respectively, and freedom from reoperation 86.3% and 96.1% respective ly. For MVR, survival in the 61-70 years age group was 16.1% at 15 years, f reedom from valve-related mortality was 59.5% and 79.5% respectively, and f reedom from valve-related reoperation 32.6% and 71.0% respectively. For MVR , survival in the >70 years age group was 2.8% at 15 years, valve-related m ortality was 26.1% and 82.0% respectively, and freedom from valve-related r eoperation 83.4% and 93.3% respectively. Conclusion: The actual freedom from valve-related mortality and valve-relat ed reoperation (primarily from structural valve deterioration), provides fu rther evidence to consider porcine bioprostheses for AVR in patients aged > 60 years, and for MVR in patients aged >70 years. The freedom from valve-re lated mortality supports the use of porcine bioprostheses for MVR in patien ts aged 61-70 years. Patient survival is influenced to the greatest extent by factors other than valve-related mortality.