Coronary artery bypass grafting in patients with severe chronic kidney disease: A propensity score-weighted analysis on the impact of on-pump versus off-pump strategies

Abstract

OBJECTIVES: The optimal surgical strategy regarding the use of cardiopulmonary bypass during coronary artery bypass grafting in patients with severe chronic kidney disease remains controversial. METHODS: Between 1997 and 2015, we identified 321 consecutive patients with severe chronic kidney disease (Stage 4 or 5) based on the National Kidney Foundation Classification (estimated glomerular filtration rate < 30 ml/min/1.73 m2). Of these, on-pump and off-pump coronary artery bypass grafting were performed in 118 and 203 patients, respectively. Surgical outcomes between the 2 groups were analysed after adjustment with propensity scores based on 30 baseline covariates. RESULTS: Early mortality occurred in 11 (9.3%) and 2 (1.0%) patients in the on- and off-pump groups, respectively (P = 0.001). The offpump group had fewer distal anastomoses than the on-pump group (3.1 ± 0.9 vs 2.8 ± 1.0; P = 0.003). After adjustment, the off-pump group showed a significantly lower risk of early death (P = 0.002), sternal wound infection (P = 0.002) and prolonged ventilation ( > 24 h) (P < 0.001). During the study period, 186 patients died, and the off-pump strategy was associated with a reduced risk of overall mortality (hazard ratio 0.61, 95% confidence interval 0.46-0.81; P < 0.001). On landmark analysis, however, cardiopulmonary bypass use was found to be unassociated with an increased risk of mortality after 1 year (P = 0.198). CONCLUSIONS: The on-pump strategy for patients with severe chronic kidney disease was associated with a significantly higher risk of mortality and morbidities, which is particularly attributable to a greater risk of cardiopulmonary bypass use in the early postoperative period. The study result suggests that the off-pump strategy might be beneficial in performing coronary artery bypass grafting, despite potentially incomplete revascularization in this high-risk cohort.