Association between preoperative aspirin and acute kidney injury following coronary artery bypass grafting.

Objective: To test the hypothesis that preoperative aspirin administered within 24 hours before coronary artery bypass grafting (CABG) could reduce the incidence of postoperative acute kidney injury (AKI) following CABG.

Methods: In this retrospective study, 696 patients were assigned to groups according to the time interval between their last aspirin dose administration and the time of surgery. A total of 322 patients received aspirin ≤24 hours before CABG, and 374 patients received aspirin between 24 and 48 hours before CABG. The primary outcome was postoperative AKI of any stage as defined by the Kidney Disease Improving Global Outcomes criteria. Propensity score matching selected 274 pairs for the final comparison.

Results: Multivariable analysis showed that administration of aspirin within 24 hours of CABG was independently associated with reduction of AKI incidence by 36% (odds ratio, 0.64; 95% confidence interval, 0.45-0.91; P = .014). It was also noted that patients receiving their last aspirin dose ≤24 hours before CABG had a significantly higher glomerular filtration rate at discharge compared with patients who received aspirin between 24 and 48 hours before CABG. Propensity score matching analysis showed that patients receiving aspirin within 24 hours before CABG had a lower incidence of AKI compared with patients who discontinued aspirin between 24 and 48 hours before CABG (25.1% vs 36.8%; P = .004).

Conclusions: Continuation of aspirin until the day of surgery, with the last aspirin dose administered ≤24 hours before CABG, is associated with a significant reduction of postoperative AKI.