Predictors of immediate and long-term outcomes of coronary bypass surgery in patients with left ventricular dysfunction

Despite encouraging improvements, outcomes of coronary artery bypass grafting (CABG) in the presence of left ventricular (LV) dysfunction remain poor. In the present study, the authors' experience on this subject was reviewed to establish the predictors of immediate and long-term results of surgery. Out of 4383 consecutive patients with multivessel coronary artery disease who underwent primary isolated CABG at the authors' institution from January 1999 throughout September 2014, 300 patients (mean age 66.1 ± 9.6 years) suffered preoperatively from LV dysfunction (defined as LV ejection fraction ≤35 %). The mean expected operative risk (EuroSCORE II) was 10.3 ± 13 %. Hospital deaths and perioperative complications were analyzed retrospectively. Outcomes were evaluated during a mean follow-up of 6.2 ± 4 years. None, one or both internal thoracic arteries (ITAs) were used in 6.3, 29 and 64.7 % of cases, respectively. There were 16 (5.3 %) hospital deaths. Prolonged invasive ventilation (17.7 %), acute kidney injury (14.7 %) and multiple blood transfusion (21.3 %) were the most frequent major postoperative complications. The 10-year non-parametric estimates of freedom from all-cause death, cardiac death, and major adverse cardiac and cerebrovascular events (MACCEs) were 47.8 [95 % confidence interval (CI) 44.1-51.5], 65.3 (95 % CI 61.4-69.2), and 42.3 % (95 % CI 38.3-46.3), respectively. Shared predictors of decreased late survival and MACCEs were old age (P < 0.04), chronic lung disease (P < 0.01), chronic dialysis (P < 0.0001) and extracardiac arteriopathy (P < 0.045). After adjustment for corresponding risk factors, freedom from cardiac death was higher when both ITAs were used but only for patients with significant increase of LV ejection fraction early after surgery (P = 0.04). In patients with LV dysfunction, CABG may be performed with acceptable hospital mortality and long-term survival. Late outcomes depend mainly on preoperative characteristics of the patients. The use of both ITAs for myocardial revascularization may give long-term survival benefits but only for patients whose LV function improves significantly early after surgery.