Association of cardiopulmonary bypass with acute kidney injury in patients undergoing coronary artery bypass grafting:a retrospective cohort study

To the Editor:Acute kidney injury(AKI)is a frequent complication of both cardiac and major non-cardiac surgeries.Cardiopulmonary bypass(CPB)-assisted cardiac surgery was associated with a higher incidence of AKI than other surgeries without CPB,suggesting that CPB might be a risk factor for cardiac surgery-associated AKI(CSA-AKI).[1]However,previous studies have demonstrated conflicting results regarding the association of CPB and CSA-AKI,as the diagnosis of AKI has been made according to different criteria.[2-5]The most recent definition of AKI from an AKI Work Group,Kidney Disease:Improving Global Outcomes(KDIGO),allows for the determination of AKI based on a decline in the glomerular filtration rate(GFR)with subsequent increase in serum creatinine or a period of oliguria.[6]We performed a retrospective cohort study to evaluate the association of CPB and postoperative AKI,using the KDIGO definition among patients undergoing on-pump or off-pump coronary artery bypass graft(CABG).