Preoperative Atrial Fibrillation And Risk Of Stroke After Noncardiac Surgery

Objective: To assess rates of postoperative stroke after elective noncardiac surgery in patients with atrial fibrillation (AF). Methods: We conducted a retrospective cohort study using all-payer administrative claims data on all non-federal hospitalizations and emergency department visits in 11 states between 2016 and 2018. We included patients hospitalized for elective noncardiac surgery, as defined by a surgical diagnosis related group and major diagnostic category codes. The exposure variable was preoperative AF. The outcome variable was ischemic stroke within 30 days of surgery. We performed survival analyses using Kaplan-Meier cumulative rates and Cox proportional hazards models. We stratified AF patients by their CHA 2 DS 2 -VASc score and tested its discrimination using the c-statistic. Results: We identified 1,301,709 patients undergoing elective noncardiac surgery, of whom 94,363 (7.3%) had preoperative AF. Patients with AF were older (mean age, 73 versus 62 years) and had higher CHA 2 DS 2 -VASc scores (mean score, 3.2 vs 2.2). We identified 2,893 patients with postoperative stroke. The cumulative rate of postoperative stroke was 0.65% (95% CI, 0.60-0.70%) in patients with AF vs 0.19% (95% CI, 0.18-0.20%) in patients without AF. After adjustment for demographics and vascular risk factors, AF was associated with a higher risk of postoperative stroke (HR, 1.7; 95% CI, 1.5-1.8). Among AF patients, the CHA 2 DS 2 -VASc score was a good predictor of postoperative stroke (AUC, 0.81; 95% CI, 0.79-0.83). Rates of postoperative stroke among AF patients ranged from <0.1% in those with a CHA 2 DS 2 -VASc score of 0-2 to 14% in those with a score of 8 (Figure). Conclusions: Patients with AF faced a heightened risk of postoperative stroke and this risk varied in proportion to the CHA 2 DS 2 -VASc score.