Acute Kidney Injury and Postoperative Atrial Fibrillation In Patients Undergoing Cardiac Surgery

Objective: To test the hypothesis that acute kidney injury (AKI) in the postoperative period could be an additional risk factor for the development of atrial fibrillation (AF) and to examine the risk factors for postoperative AF in the authors’ cohort of patients. Design: A retrospective observational study. Setting: Large regional cardiothoracic surgical center in the UK. Participants: Patients undergoing elective cardiac surgery at the authors’ institution between July 1, 2013, and December 31, 2018. Interventions: None. Measurements and Main Results: A total of 5,588 patients were included in the study. The incidence of postoperative AF was 1,384 (24.8%), and postoperative AKI occurred in 686 patients (12.3%). Postoperative AKI was significantly associated with postoperative AF after adjustment for preoperative variables (adjusted odds ratio = 1.572; 95% confidence interval = 1.295-1.908; p < 0.001). Other factors associated with postoperative AF were increasing age; increasing body mass index; New York Heart Association class ≥III; previous congestive heart failure; and recent myocardial infarction, coronary artery bypass graft with valve surgery, and aortic surgery (all p < 0.05). Conclusions: This analysis of a large, contemporary cohort of patients identifies postoperative AKI as an associated risk factor for postoperative AF, along with other perioperative variables. Early identification of this patient cohort would allow targeted preventative treatment to reduce the incidence of postoperative AF.