On-pump versus off-pump coronary artery bypass surgery in patients with preoperative anemia

The study objective was to evaluate the effects on early outcome and midterm survival of performing coronary artery bypass grafting with the off-pump technique in comparison with cardiopulmonary bypass (on-pump) in patients with preoperative anemia.

Consecutive adult anemic patients (preoperative hemoglobin <13.0 g/dL in men and <12.0 g/dL in women) resident in Puglia region who underwent isolated coronary artery bypass grafting between January 2011 and November 2013 were considered. Vital status was ascertained from the date of surgery to December 31, 2013. Odds ratio and hazard ratio (HR) were estimated. Propensity score methods were used to control for confounders.

Of 939 anemic patients (234 female, aged 71 ± 9 years), 361 underwent operation with the off-pump technique and 578 underwent operation with the on-pump technique. Patients undergoing off-pump coronary artery bypass had a shorter intensive care unit length of stay, lower blood transfusion rate, and postoperative reduction in creatinine clearance. During a median follow-up of 18 months, 126 patients died: 46 in hospital (35 on-pump) and 80 after discharge (33 on-pump). In comparison with the off-pump technique, the on-pump technique had greater hospital mortality (odds ratio, 2.57; P = .028) and 30-day incidence of fatal events (HR, 2.67; P = .026). After a period without risk differences between groups (1-6 months; HR, 0.79; P = .618), a lower mortality in those undergoing the on-pump technique was detected (after 6 months HR, 0.35; P = .014). All results were confirmed in the 157 pairs of patients matched for propensity score, anemia grade, and surgery center.

In patients with low levels of preoperative hemoglobin, off-pump coronary artery bypass was associated with lower early morbidity and mortality but a greater risk of mortality during follow-up compared with on-pump coronary artery bypass.