Coronary Bypass Surgery Performed off Pump versus on Pump - Coronary Bypass Surgery Performed off Pump versus on Pump


The goal of the trial was to compare outcomes of coronary-artery bypass surgery without cardiopulmonary bypass (CPB) ("off pump") versus conventional "on-pump" surgery.

Study Design

Study Design:

Patients Screened: 933
Patients Enrolled: 300
Mean Follow Up: hospital discharge
Mean Patient Age: mean age 63 years
Female: 20
Mean Ejection Fraction: EF >50% at baseline was 84.7% in the on-pump group and 86.7% in the off-pump group (p=NS).

Patient Populations:

Need for CABG surgery


Emergency procedure (requiring immediate surgery), concomitant major cardiac procedures, ejection fraction <30%, and reoperation.

Drug/Procedures Used:

Patients requiring coronary artery bypass graft (CABG) surgery were randomized to have the procedure performed with CPB (i.e., on-pump; n=150) or on the beating heart (i.e., off-pump; n=150). Randomization was done intraoperatively after evaluating the coronary anatomy to ensure either procedure could be performed safely. The study was conducted at a single center with 6 participating surgeons.

Principal Findings:

20 patients crossed over from on-pump to off-pump CABG. Triple vessel disease was present in 74.0% of patients in the on-pump group and 67.3% in the off-pump group (p=0.18). The mean number of grafts done was 3.0 in the on-pump group and 2.8 in the off-pump group (p=0.06). Complete arterial revascularization of grafts was similar in both groups (64% vs 68%, p=0.46).

There was no difference in in-hospital mortality between groups (0.7% vs 1.3%, p=1.0) but the overall number of deaths was small (n=3). There was also no difference in other clinical events, including perioperative myocardial infarction (0.7% vs 2.7%; p=0.37), permanent stroke (0% vs 1.3%; p=0.50), new atrial fibrillation (32% vs 25%; p=0.20), and deep sternal wound infection (0.7% vs 0%; p=1.0), or the composite of death/IABP/MI/stroke/long ventilation (4.0% vs 6.0%, p=0.43). The transfusion rate did not differ between groups (8.7% vs 9.3%, p=0.84). Median length of hospitalization was 5 days in both groups (p=0.84), and median ICU length of stay was 22 hours in both groups (p=0.97).


Among patients undergoing CABG surgery, use of off-pump surgery was not associated with differences in clinical events or length of stay compared with on-pump surgery. Previous studies have examined the issue of on-pump vs off-pump CABG surgery but many have been small, non-randomized or single center studies and results have been mixed. The present study is the largest of the 3 randomized trials to date, and patients enrolled in the trial were relatively high risk (71% had 3-vessel disease, 33% diabetic).


Légaré JF, et al. Coronary Bypass Surgery Performed off Pump Does Not Result in Lower In-Hospital Morbidity Than Coronary Artery Bypass Grafting Performed on Pump. Circulation. 2004;109:887-892.

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

Keywords: Coronary Artery Disease, Myocardial Infarction, Stroke, Hospital Mortality, Wound Infection, Cardiopulmonary Bypass, Coronary Artery Bypass, Diabetes Mellitus, Length of Stay

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