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 grafting (CABG) on valve-related complications by valve position was evaluated in a population of 2353 bioprosthesis patients (mean age, 66.5 years; range, 13 to 89 years) and in a population of 1112 mechanical prosthesis patients (mean age, 59.1 years; range, 13 to 91 years). The follow-up was complete to 96% and 98%, respectively, for the bioprosthesis and mechanical prosthesis groups. The patient groups were evaluated by actuarial assessment of survival and valve complications and composites. Preoperative factors were evaluated for determination of significant independent predictors by multivariate proportional-hazard regression analysis. CABG was an influential factor in the actuarial analysis. Survival was superior for aortic mechanical replacements without CABG and for mitral replacements, both biological and mechanical, without CABG ( P <.05). The freedom from thromboembolism (TE) and antithromboembolic hemorrhage (ATH) was greater for biological prostheses with and without CABG for aortic replacements ( P <.05) but not for mitral replacements ( P =NS). The freedom from valve-related mortality was not influenced by CABG for either position ( P =NS). The freedom from valve-related reoperation was greater for biological prostheses with CABG than without CABG for both aortic and mitral replacements ( P <.05). The evaluation of covariates as independent predictors revealed CABG to be a nonpredictor 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 freedom from valve-related mortality and TE and ATH ( P <.05) and for MVR for 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 of assessment. Advancing age for MVR provided a lower rate of survival and greater freedom from valve-related mortality and reoperation ( P <.05). The clinical performance of valvular prostheses is influenced to a greater degree by valve type and age than by CABG.