Impact of mitral insufficiency on reoperative coronary artery surgery in ischemic cardiomyopathy patients?

Abstract

To determine the impact of mitral insufficiency on survival after reoperative coronary artery bypass grafting (CABG) in ischemic cardiomyopathy patients. We retrospectively studied 891 (Initial 708, Redo 183) consecutive CABG patients (1993-2002) with ejection fraction (EF) 35% or less. mean age=67.0+/-10.5 yrs, men=77.1%, EF=26.4+/-7.4%, mean CCS=3.47+/-0.73, mean NYHA=3.50+/-0.68. There were 180 (Initial 141, Redo 39) patients with 3/4+mitral regurgitation (MR). Late survival statistics of cohorts were compiled using National Death Index. At a mean follow-up period of 3 years, reoperative CABG with MR (Redo/MR+) survival was 41.7+/-9.2% (n=39), which was worse than reoperative CABG without MR (Redo/MR-) survival of 71.8+/-4.1% (n=144, P=0.0003), initial CABG with MR (Initial/MR+) survival of 68.5+/-4.2% (n=141, P=0.014) and initial CABG without MR (Initial/MR-) survival of 76.2+/-2.0% (n=567, P<0.0001). By multivariate analysis, congestive heart failure (P=0.029), 3/4+MR (P=0.044) were independent predictors of Redo late mortality. In contrast, renal failure on dialysis, stroke, no angina, age >65 yrs, absence of hypercholesterolemia, EF<26% but not 3/4+MR were independent predictors of Initial late mortality. In subset analysis, adverse impact of 3/4+MR on late survival was greatest in Redo with EF<26%. The 3- and 5-yr late survival were only 44.4 and 26.8% (P=0.041). Concomitant mitral valve repair (MVrep) was performed in 100 (Initial 75, Redo 25) patients. MVrep in Initial/MR+patients achieved similar late survival as Initial/MR- patients. MVrep did not produce the same late survival benefit in Redo/MR+ patients. (1) Mitral insufficiency has a greater survival impact on redo than initial CABG patients with ischemic cardiomyopathy. (2) Mitral insufficiency and congestive heart failure are the primary independent predictors of late survival following redo CABG. (3) Mitral repair has less neutralizing effect on late survival in redo than initial CABG patients.