INFLUENCE OF CORONARY-ARTERY BYPASS AND AGE ON CLINICAL-PERFORMANCE AFTER AORTIC AND MITRAL-VALVE REPLACEMENT WITH BIOLOGICAL AND MECHANICAL PROSTHESES

The influence of prosthetic type, age, and coronary artery bypass graf ting (CABG) on valve-related complications by valve position was evalu ated in a population of 2353 bioprosthesis patients (mean age, 66.5 ye ars; range, 13 to 89 years) and in a population of 1112 mechanical pro sthesis patients (mean age, 59.1 years; range, 13 to 91 years). The fo llow-up was complete to 96% and 98%, respectively, for the bioprosthes is and mechanical prosthesis groups. The patient groups were evaluated by actuarial assessment of survival and valve complications and compo sites. Preoperative factors were evaluated for determination of signif icant independent predictors by multivariate; proportional-hazard regr ession analysis. CABG was an influential factor in the actuarial analy sis. Survival was superior for aortic mechanical replacements without CABG and for mitral replacements, both biological and mechanical, with out CABG (P<.05). The freedom from thromboembolism (TE) and antithromb oembolic hemorrhage (ATH) was greater for biological prostheses with a nd without CABG for aortic replacements (P<.05) but not for mitral rep lacements (P=NS). The freedom from valve-related mortality was not inf luenced by CABG for either position (P=NS). The freedom from valve-rel ated reoperation was greater for biological prostheses with CABG than without CABG for both aortic and mitral replacements (P<.05). The eval uation of covariates as independent predictors revealed CABG to be a n onpredictor for aortic valve replacement (AVR) (P=NS) but a predictor of survival and valve-related reoperation for mitral valve replacement (MVR) (P<.05). With AVR, biological prostheses predicted greater free dom from valve-related mortality and TE and ATH (P<.05) and for MVR fo r TE and ATH (P<.05). Valve position was not a predictor otherwise (P= NS). Advancing age was a significant covariate for AVR for all areas o f assessment. Advancing age for MVR provided a lower rate of survival and greater freedom from valve-related mortality and reoperation (P<.0 5). The clinical performance of valvular prostheses is influenced to a greater degree by valve type and age than by CABG.