On-Pump versus Off-Pump Coronary Bypass Grafting in Patients with Non–Dialysis-Dependent Renal Impairment

Objectives: In patients who receive coronary artery bypass grafting (CABG), preoperative renal dysfunction is a strong predictor for postoperative acute kidney injury (AKI) and mortality. However, it remains controversial, whether waiving cardiopulmonary bypass (CPB) could reduce the risk for postoperative AKI. We therefore compared postoperative renal function in patients with preoperative renal dysfunction undergoing On- versus Off-pump CABG.

Methods: From January 2015 to May 2017, a total of 7,352 consecutive patients who underwent isolated CABG in 16 European centers were registered in the E-CABG database. Emergency patients, patients in preoperative critical state and patients with ejection fraction less than 21% were excluded from analysis. Of the remaining patients, 4,776 presented with mild or moderate renal dysfunction based on glomerular filtration rate (GFR) according to the chronic kidney disease (CKD) staging. Renal function and follow-up parameters were analyzed and compared between groups using logistic regression analysis.

Result: In this cohort, 3,776 (79.1%) patients underwent ONCAB and 1,000 (20.9%) received OPCAB procedures. OPCAB patients were significantly older than ONCAB patients (ONCAB: 69.9 ± 8.2, OPCAB: 71.5 ± 8.2; p < 0.001). Preoperatively, the OPCAB group showed a significantly reduced GFR compared with the ONCAB group (ONCAB: 69.95 ± 14.62 mL/min/1.73 m², OPCAB 66.97 ± 15.24 mL/min/1.73 m², p < 0.001). Adjusted logistic regression analysis revealed that OPCAB patients showed a higher rate of AKI (ONCAB 21.9% (n = 827), OPCAB 27.6% (n = 276), p < 0.017, OR 1.23) after the procedure. There was no statistically significant difference in the postoperative need for dialysis (ONCAB 1.3%, OPCAB 2.1%, p = 0.303). Furthermore, there were no differences between ONCAB and OPCAB groups with respect to 30-day or in-hospital mortality (1.7% = 63 vs. 1.5% = 15; p = 0.709) or in-hospital stay (9.9 ± 6.8 vs. 9.7 ± 6.0 d, p = 0.516). However, the incidence of postoperative stroke (ONCAB 1.4% (n = 53), OPCAB 0.2% (n = 2), p = 0.002) was significantly higher in the ONCAB group.

Conclusion: As we adjusted for preoperative differences between the groups (i.e., in age and preoperative renal function), logistic regression analysis revealed that waiving CPB is associated with a higher risk of postoperative AKI. However, this does not lead to a difference between the groups in the need for renal replacement therapy or in short-term survival.

Publication History

Article published online:
19 February 2021