Off-pump versus on-pump coronary bypass. Comparison of patient characteristics and early outcomes

This clinical report details a comparison between the conventional on-pump and beating heart off-pump techniques with particular attention to patient characteristics, perioperative variables and early outcomes.

We collected prospectively a comprehensive data body from 1131 consecutive patients who underwent isolated CABG in Tampere University Hospital. The morbidity, mortality and length of stay data from the secondary referral hospitals were also collected. One thousand and sixteen (89.8%) patients underwent bypass grafting with cardiopulmonary bypass (CPB, on-pump) and 115 (10.2%) patients without the CPB (off-pump).

Thirty-day mortality rates were 4.0% (on-pump) and 2.6% (off-pump, p=0.5). The total postoperative length of stay was 12 (on-pump) and 10 (off-pump) days as the medians (p<0.001). Adverse outcome events among the on-pump and off-pump patients were as follows: postoperative stroke, 2.5% and 0.9% (p=0.3); perioperative myocardial infarction, 7.0% and 7.8% (p=0.7); impaired renal function, 9.5% and 4.3% (p=0.3); re-sternotomy for bleeding or low output, 5.3% and 4.3% (p=0.2); new-onset atrial fibrillation, 38.9% and 24.6% (p=0.002) and the need for red cell transfusions in ICU, 50.3% and 22.6% (p<0.001). Eighty-three percent of the on-pump and 85.2% of the off-pump patients (p=0.5) had a favorable outcome without a major complication.

Considering the limitations with a nonrandomized study design, we conclude that off-pump CABG is a safe and comparable method of myocardial revascularization in terms of early outcomes. Overall length of stay shorter by 2 days, over a third shorter ventilation time, fewer red cell transfusions and lower frequency of postoperative atrial fibrillation favor off-pump surgery.