Survival After Isolated Coronary Artery Bypass Grafting in Patients With Severe Left Ventricular Dysfunction

Background. The number of patients with severe left ventricular dysfunction referred for coronary artery bypass graft surgery (CABG) continues to increase. The aim of this study was to document the long-term survival in this group.

Methods. The 30-day mortality and long-term survival outcome of 162 patients with severely depressed left ventricular ejection fraction (LVEF [<30%]) who had consecutive isolated CABG between 1996 and 2005 were compared with 661 patients who had impaired LVEF (31% to 59%) and 1,231 patients with normal LVEF (>60%).

Results. The 30-day mortality for patients with severely depressed LVEF was 5.6%. The median survival for deceased patients was 3.4 years (interquartile range, 1.3 to 5.9). The risk of all-cause mortality attributable to severe left ventricular dysfunction was increased twofold compared with having normal LVEF (hazard ratio 2.28" 95% confidence interval: 1.64 to 3.18" p < 0.001). Among the covariates, older age, emergency surgery, mitral incompetence, smoking history, respiratory disease, diabetes mellitus, cerebrovascular disease, intensive care unit intubation for 24 hours or more, postoperative renal failure, postoperative pleural effusion, and nonuse of left internal mammary artery were detected as significant predictors of increased mortality risk.

Conclusions. The mortality rate among CABG patients with severely depressed LVEF was comparable to that reported in other series. Severe left ventricular dysfunction carried more than a twofold increased mortality risk compared with patients who had an impaired LVEF, adjusted for traditional risk factors. These data suggest that LVEF has an impact on long-term patient survival even after preoperative covariates and postoperative morbidity outcomes are considered.