Off-pump and on-pump coronary revascularization in patients with low ejection fraction: a report from the society of thoracic surgeons national database

Abstract

Background: The purpose of this study was to evaluate outcomes of patients with low ejection fraction who underwent surgical coronary revascularization with or without cardiopulmonary bypass (CPB).

Methods: The Society of Thoracic Surgeons National Database was queried from January 1, 2008, to June 30, 2011 for patients with an ejection fraction of less than 0.30 who underwent primary, nonemergent coronary artery bypass (CAB) grafting. The entire cohort of 25,667 patients was divided into those who underwent revascularization with (ONCAB, n = 20,509) and without (OPCAB, n = 5,158) CPB. OPCAB patients who were converted to CPB intraoperatively were counted as intended OPCAB and were included in the OPCAB group. Propensity scores were estimated using 32 covariates, and multivariate logistic regression was used to compare risk-adjusted outcomes between groups.

Results: Patients undergoing planned OPCAB were older, more frequently female, and had a lower body mass index than those who underwent ONCAB. The OPCAB cohort also had higher rates of prior stroke, peripheral vascular disease, and chronic lung disease. The predicted mortality risk was 2.3% for the OPCAB cohort vs 2.1% for the ONCAB group (p < 0.0001). Of the 5,158 patients who underwent OPCAB, unplanned conversion to CPB occurred in 270 (5.2%). OPCAB was associated with significantly lower adjusted risk of death (odds ratio [OR], 0.82), stroke (OR, 0.67), major adverse cardiac events (OR, 0.75), and prolonged intubation (OR, 0.78). Postoperative transfusion rates were significantly lower in the OPCAB group (44.8% vs 51.6%, p < 0.001). There were no adverse outcomes that occurred more commonly in OPCAB patients. The advantage associated with OPCAB was found in the entire Society of Thoracic Surgeons National Database and among high-volume and low-volume OPCAB centers.

Conclusions: In The Society of Thoracic Surgeons National Database, OPCAB is associated with significantly reduced adjusted risk of early morbidity and mortality for patients having coronary bypass grafting with an ejection fraction of less than 0.30.