Objectives: Coronary artery revascularization with cardiopulmonary bypass (ONCAB) has been reported to carry several risks for patients with poor left ventricular (LV) function (ejection fraction <30%). Off-pump CABG (OPCAB) has been proposed to result in a better outcome, but mid- and long-term survival rates have never been compared. The aim of this study is to assess the effect of cardiopulmonary bypass on this group of patients.
Methods: In a 10-year period, a total of 934 patients with poor LV function undergoing isolated first-time coronary artery bypass graft were studied. They were divided into two groups, the ONCAB group, with 528 patients, and the OPCAB group with 406 patients. The EuroSCORE was significantly higher in the OPCAB group (P=0.049). After adjusting for the preoperative characteristics, postoperative complications, in-hospital mortality, mid-term survival rate (five years), and long-term survival rate (10 years) were compared.
Results: The average number of grafts was 3.7 in the ONCAB group and 3.1 in the OPCAB group (P<0.001). Postoperative complications of ONCAB and OPCAB groups such as; atrial fibrillation (29.6% vs. 28.6%), renal failure (9.3% vs. 9.6%), stroke (2.3% vs. 0.7%), and perioperative myocardial infarction (MI) (3.8% vs. 2.0%), were comparable between groups. Length of intensive care unit stay, hospital stay and ventilation time were considerably shorter in the OPCAB group (P<0.05). The incidence of wound infection was also lower in the OPCAB patients (P<0.05). After adjusting for the preoperative characteristics the incidence of most postoperative complications remained the same between the two groups, except for MI, which was lower in the OPCABs (P<0.04). Despite a lower number of proximal anastomoses in the OPCAB patients, the rate of stroke remained the same between the OPCAB and ONCAB patients (0.09% vs. 1.6%). In-hospital mortality was higher in ONCAB compared to OPCAB (7.8% vs. 5.7%), but this difference did not reach statistical significance (P=0.21). Likewise, mid-term and long-term survival rates were similar even with matched preoperative characteristics. However, re-intervention rate was found to be higher in the OPCABs (P<0.001).
Conclusions: Despite the reported benefits of OPCAB, there was no significant influence on the in-hospital mortality, mid-term survival or long-term survival in patients with LV dysfunction. With adequate myocardial protection in ONCAB and complete revascularization in OPCAB, similar results are achievable.