Postoperative Atrial Fibrillation Following Non-Cardiac Surgery: The Impact of Medical History and Surgical Type.

BACKGROUND: Postoperative atrial fibrillation (POAF) is well recognized after cardiac surgery; however, its incidence and clinical course following non-cardiac surgery (NCS) remain unclear. OBJECTIVES: To evaluate the association between POAF after NCS, patient co-morbidities, and type of surgery. METHODS: In this retrospective cohort study, patients who underwent NCS at a private hospital network between 2016 and 2023 were included. Patients with a history of atrial fibrillation (AF) were excluded. Patients who developed POAF within 24-48 hours were compared with those who did not. To address baseline differences, propensity score matching (1:10) and inverse probability weighting combined with Firth's penalized logistic regression were applied. Odds ratios with 95% confidence intervals were calculated. RESULTS: POAF developed in 174 patients within 24-48 hours postoperatively, compared with 391,329 controls. Older age, ischemic heart disease, diabetes, and prior stroke were associated with increased odds of POAF, although significance diminished after multivariable adjustment. Weighted regression confirmed these findings with narrower confidence intervals. Higher POAF risk was observed after laparoscopic pancreatectomy, hepatectomy, rectopexy, synovectomy, and gastrectomy. Total knee replacement was the most common procedure among POAF cases, representing 22% of cases and a fourfold increased risk. CONCLUSIONS: Advanced age and cardiovascular co-morbidities were associated with increased POAF risk after NCS, although attenuated after adjustment. Consistent findings across statistical models support the robustness of the results. Targeted monitoring in high-risk patients may improve postoperative outcomes.