Preoperative central nervous system stimulant exposure and atrial fibrillation after coronary artery bypass grafting: a propensity-matched federated cohort study

Background Postoperative atrial fibrillation is a common complication of coronary artery bypass grafting (CABG), and prescription stimulant use is increasing among adults. We evaluated the association between recorded preoperative stimulant exposure and atrial fibrillation or flutter after CABG. Methods Using the TriNetX Research Network, we compared patients with an order for 1 of 6 stimulants within 3 months before or on the date of CABG with patients without a recorded order. Patients with atrial fibrillation or flutter documented at least 1 day before CABG were excluded before matching. Cohorts were matched 1:1 on 43 characteristics. The primary outcome occurred during postoperative days 1 through 30. Results Among 1082 matched patients per group, atrial fibrillation or flutter occurred in 147 exposed patients (13.6%) and 115 controls (10.6%; risk ratio [RR] 1.28, 95% confidence interval [CI] 1.02–1.61; P = 0.035). The risk difference was 3.0 percentage points (95% CI 0.2–5.7) and the hazard ratio was 1.29 (95% CI 1.01–1.65). Sensitivity analyses remained above the null but varied in magnitude (RR range 1.28–2.47). Conclusions Recorded preoperative stimulant exposure was associated with a modestly higher rate of atrial fibrillation or flutter after CABG. The direction of association was consistent across sensitivity analyses, although the magnitude varied with cohort and outcome definitions. These observational data do not establish causality or support a specific perioperative medication strategy.