On-Pump and Off-Pump Coronary Artery Bypass Grafting in Patients With Left Main Stem Disease: A Propensity Score Analysis

Study Questions:

What is the comparative safety and efficacy between off-pump coronary artery bypass grafting (OPCAB), and conventional on-pump coronary artery bypass grafting (CCAB) in patients with left main stem disease?


In a retrospective, observational, cohort study of prospectively collected data on 2,375 consecutive patients with left main stem disease undergoing isolated CABG (1,297 OPCAB, 1,078 CCAB) between April 1996 and December 2009 at the Bristol Heart Institute, 548 patients undergoing OPCAB were matched with 548 patients undergoing CCAB by propensity score.


After propensity matching, groups were comparable in preoperative characteristics. Relative to CCAB, OPCAB was associated with lower in-hospital mortality (0.5% vs. 2.9%; p = 0.001), incidence of stroke (0% vs. 0.9%; p = 0.02), postoperative renal dysfunction (4.9% vs. 10.8%; p = 0.001), pulmonary complications (10.2% vs. 16.6%; p = 0.002), and infectious complications (3.5% vs. 6.2%; p = 0.03). The OPCAB group received fewer grafts than did the CCAB group (2.7 ± 0.7 vs. 3 ± 0.7; p = 0.001) and had a lower rate of complete revascularization (88.3% vs. 92%; p = 0.04). In multivariable analysis, cardiopulmonary bypass was confirmed to be an independent predictor of in-hospital mortality (odds ratio, 5.74; p = 0.001). Survivals at 1, 5, and 10 years were similar between groups (OPCAB, 96.8%, 87.3%, and 71.7%; CCAB, 96.8%, 88.6%, and 69.8%).


The authors concluded that OPCAB in patients with left main stem disease is a safe procedure with reduced early morbidity and mortality, and similar long-term survival to conventional on-pump revascularization.


This study suggests that OPCAB is safe for patients with left main stem coronary artery disease, and is associated with improved early morbidity and mortality, and similar long-term survival at 10 years with respect to CCAB. It is possible that a longer follow-up period might reveal a decreased long-term survival associated with incomplete revascularization in OPCAB. Also, it is important to note that when comparing the entire cohort study population, OPCAB was associated with a higher incidence of incomplete revascularization. A prospective study with longer follow-up is required to understand the effects of incomplete revascularization in this subset of patients.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Atherosclerotic Disease (CAD/PAD), Interventions and Coronary Artery Disease

Keywords: Survivors, Incidence, Coronary Artery Disease, Stroke, Follow-Up Studies, Hospital Mortality, Morphine Derivatives, Coronary Artery Bypass, Off-Pump, Cardiopulmonary Bypass

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