Impacts of incomplete revascularization following off-pump coronary artery bypass grafting on clinical outcomes of patients with triple-vessel lesions: insights from a single-center study of propensity-matched data

Background: Although complete revascularization (CR) has been a goal of surgical revascularization, comorbidities and anatomical variables often conspire against a successful surgical CR. Currently, incomplete revascularization (IR) has been also considered as an acceptable strategy of surgical revascularization in some categories of patients. In the past decade, off-pump coronary artery bypass grafting (CABG) became one of the mainstream procedures of CABG due to its low incidence of perioperative complications. However, the magnitude of the impacts of off-pump IR on clinical outcomes of patients with triple-vessel disease remained unclear. Methods: Eligible patients who received isolated off-pump CABG with left internal mammary artery (LIMA) grafting to the left anterior descending coronary artery (LAD) in our institute from January 2011 to December 2013 were entered into an IR group or a CR group. The incidence of off-pump IR was investigated. In-hospital and follow-up outcomes were also evaluated by adjusting baseline characteristics using propensity score matching (1:1). Results: A total of 1,349 patients (268 in the IR group and 1,081 in the CR group) were analyzed. The off-pump IR rate was 19.9%. Using matching propensity scores, 234 pairs were successfully established in a 1:1 manner. The two matched groups had similar surgical mortality and major postoperative morbidity. Multivariate Cox regression analysis showed that IR was not an independent predictor of cardiac death at follow-up (HR=1.215; 95% CI, 0.883-2.164; P=0.371). The two matched groups received a similar cumulative survival freedom from repeat revascularization in Kaplan-Meier curves (chi(2)=2.120, log-rank P=0.145). Conclusions: CR can be achieved in the majority of off-pump CABG cases. Compared with off-pump CR, off-pump IR with the LIMA grafting to the LAD was associated with acceptable clinical outcomes.