Background: The clinical benefits of a concomitant mitral valve (MV) surgery in patients with moderate ischemic mitral regurgitation (iMR) undergoing coronary artery bypass grafting (CABG) remain controversial.
Methods: The study involved 710 patients (mean age, 65.0±8.9 years; 504 males) with moderate iMR undergoing CABG between 1990 and 2015. Of these, 116 (16.3%) patients underwent a concomitant MV surgery (MVS; replacement in 10, repair in 106) and 594 (83.7%) underwent CABG only. Clinical and echocardiographic outcomes were compared before and after adjustment with the use of propensity score (PS) analyses.
Results: Early mortality occurred in 22 (3.7%) and 13 (11.2%) patients in CABG-only and CABG with MVS group, respectively (P=0.001). After adjustment, CABG with MVS group showed significantly increased risks of early death (P<0.001), low cardiac output syndrome (LCOS) (P=0.001) and surgical bleeding (P=0.014). During a median follow-up of 78.0 months (quartile 1-3, 33.6-115.9 months), overall mortality occurred in 286 (40.3%) patients. The addition of an MV surgery showed an increased risk of overall mortality [hazard ratio (HR), 1.34; 95% confidence interval (CI), 0.99-1.80; P=0.055], which became comparable 1 year after surgery on landmark survival analysis (HR, 0.94; 95% CI, 0.64-1.39; P=0.772). Improved left ventricular (LV) ejection fraction and LV reverse remodeling were observed in both groups without significant intergroup differences.
Conclusions: The addition of a concomitant MV surgery increased the risk of early mortality and complications in patients with moderate iMR undergoing CABG. In long-term clinical and echocardiographic outcomes, a concomitant MV surgery seemed to confer no significant clinical benefits.
Keywords: Ischemic mitral regurgitation (iMR); coronary artery bypass grafting (CABG); mitral valve surgeryv.