Carpentier-Edwards porcine bioprostheses: clinical performance assessed by actual analysis

The clinical performance of porcine bioprostheses for valve replacement has been evaluated for over three decades by actuarial analysis as the standard for reporting time-related results. Actual or cumulative incidence analysis provides a complementary method to determine the manifestations of valve-related complications due primarily to structural valve deterioration. Valve-related mortality and reoperation of porcine bioprostheses for aortic and mitral valve replacement was compared by actuarial and actual methodology.

The Carpentier-Edwards porcine bioprostheses were implanted between 1975 and 1995 as 2,237 aortic valve replacements (AVR) and 1,582 mitral valve replacements (MVR). Coronary artery bypass was performed in 36.4% of AVR, 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 (mean 6.6 years) for AVR and 9,718 patient-years (mean 6.1 years) for MVR.

Patient survival, and actuarial and actual freedom from valve-related mortality and valve-related reoperation was reported at 15 years. For AVR, survival in the 61-70 years age group was 30.9%, freedom from valve-related mortality was 79.3% and 86.9% respectively, and freedom from valve-related 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% respectively. For MVR, survival in the 61-70 years age group was 16.1% at 15 years, freedom from valve-related mortality was 59.5% and 79.5% respectively, and freedom 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 mortality was 26.1% and 82.0% respectively, and freedom from valve-related reoperation 83.4% and 93.3% respectively.

The actual freedom from valve-related mortality and valve-related reoperation (primarily from structural valve deterioration), provides further evidence to consider porcine bioprostheses for AVR in patients aged >60 years, and for MVR in patients aged >70 years. The freedom from valve-related mortality supports the use of porcine bioprostheses for MVR in patients aged 61-70 years. Patient survival is influenced to the greatest extent by factors other than valve-related mortality.