Pulsatile cardiopulmonary bypass using a centrifugal pump reduces acute kidney injury after cardiac surgery: a propensity score-matched analysis.

Objective: Acute kidney injury (AKI) affects approximately 30% of patients undergoing cardiac surgery with conventional non-pulsatile cardiopulmonary bypass (CPB). Pulsatile flow has long been proposed for mitigating this complication. While the 2019 EACTS guidelines recommend pulsatile perfusion for high-risk renal patients, most evidence is based on intra-aortic balloon pump (IABP) studies, with limited evidence for centrifugal pumps. We aimed to evaluate whether pulsatile CPB using a centrifugal pump reduces postoperative AKI in patients undergoing cardiac surgery.

Methods: This retrospective study analyzed 824 patients who underwent cardiac surgery between December 2008 and December 2023. The patients were divided into pulsatile perfusion (PP) and non-pulsatile perfusion (NP) groups. Propensity score matching was adjusted for the baseline characteristics, resulting in 265 matched pairs. The primary endpoint was postoperative AKI, defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Subgroup analyses were performed based on estimated glomerular filtration rate (eGFR).

Results: In the matched cohort, the PP group had a significantly lower incidence of AKI than the NP group (20.8 vs. 34.3%; odds ratio, 0.5; 95% confidence interval, 0.33-0.75; P < 0.001). A subgroup analysis showed that patients with a preoperative eGFR of 15-60 had a significantly lower incidence of AKI in the PP group (28.3 vs. 47.1%; P = 0.005). No significant differences were observed in secondary outcomes, including hemodialysis, cerebrovascular events, and in-hospital mortality.

Conclusions: Pulsatile CPB using a centrifugal pump significantly reduced the incidence of postoperative AKI in cardiac surgery patients, particularly in those with preoperative renal impairment.