Postoperative Atrial Fibrillation Following Noncardiac Surgery Increases Risk of Stroke

Background: New-onset postoperative atrial fibrillation is well recognized to be an adverse prognostic marker in patients undergoing noncardiac surgery. Whether postoperative atrial fibrillation confers an increased risk of stroke remains unclear. Methods: A systematic review and meta-analysis was performed to assess the risk of stroke after postoperative atrial fibrillation in noncardiac surgery. MEDLINE, Cochrane, and EMBASE databases were searched for articles published up to May 2019 for studies of patients undergoing noncardiac surgery that reported incidence of new atrial fibrillation and stroke. Event rates from individual studies were pooled and risk ratios (RR) were pooled using a random-effects model. Results: Fourteen studies of 3,536,291 patients undergoing noncardiac surgery were included in the quantitative analysis (mean follow-up 1.4 ± 1 year). New atrial fibrillation occurred in 26,046 (0.74%), patients with a higher incidence following thoracic surgery. Stroke occurred in 279 (1.5%) and 6199 (0.4%) patients with and without postoperative atrial fibrillation, respectively. On pooled analysis, postoperative atrial fibrillation was associated with a significantly increased risk of stroke (RR 2.51; 95% confidence interval, 1.76-3.59), with moderate heterogeneity. The stroke risk was significantly higher with atrial fibrillation following nonthoracic, compared with thoracic, surgery (RR 3.09 vs RR 1.95; P =. 01). Conclusion: New postoperative atrial fibrillation following noncardiac surgery was associated with a 2.5-fold increase in the risk of stroke. This risk was highest among patients undergoing nonthoracic noncardiac surgery. Given the documented efficacy of newer anticoagulants, randomized controlled trials are warranted to assess whether they can reduce the risk of stroke in these patients.