RANDOMIZED, PROSPECTIVE ASSESSMENT OF BIOPROSTHETIC VALVE DURABILITY - HANCOCK VERSUS CARPENTIER-EDWARDS VALVES

Background. Although the major limitation of porcine valves is their f inite durability, no controlled clinical data exist regarding the rela tive durability of the two porcine bioprostheses implanted most common ly today, the Carpentier-Edwards (C-E) and Medtronic Hancock I (H) val ves. Methods and Results. To assess this question, 174 patients underg oing aortic (AVR) or mitral (MVR) valve replacement with a bioprosthes is between March 1980 and March 1982 were randomized to receive either a C-E or a H valve. There were 102 AVRs (54 C-E and 48 H) and 74 MVRs (39 C-E and 35 H). For both the AVR and MVR cohorts, the average pati ent age was 58+/-14 years (+/-SD). The male/female ratio was 2.2:1 for AVR and 0.57:1 for MVR. Clinical follow-up was undertaken periodicall y; the most recent follow-up closing interval was July through October 1992, and current follow-up was 96% complete. Cumulative follow-up to taled 1369 patient-years (mean, 7.7+/-3.6 years; median, 9.1 years; ma ximum, 12.0 years). The main focus of this analysis was bioprosthetic durability, using the AATS/STS guidelines defining ''Structural Valve Deterioration'' (SVD). Multivariate analysis revealed that (younger) a ge was the only significant (P=.024) independent predictor of SVD. Val ve manufacturer (C-E versus H) and valve site (aortic versus mitral) d id not emerge as significant independent risk factors for SVD. Actuari al rates (Cutler-Ederer) expressed as percent free of SVD (+/-SEM) at 10 years (n=number of patients remaining at risk) were 71+/-7% and 59/-9% for the C-E (n=26) and H (n=17) groups, respectively, for the AVR cohort; for the MVR cohort, these estimates were 60+/-10% (n=12) and 72+/-10% (n=11), respectively, but these differences were not statisti cally significant (P=NS, Lee-Desu). Conclusions. After 10 years, there was no statistically significant difference in durability or other va lve-related complications between the H and C-E aortic or mitral valve s. Based on current information, the choice of a porcine bioprosthesis should be based on factors other than durability, including ease of i mplantation, hemodynamic performance, and cost.