Postoperative Atrial Fibrillation Study

USA: Postoperative atrial fibrillation (AF) after noncardiac surgery is tied to a similar risk of thromboembolism versus nonoperative AF, researchers report in a study published in Annals of Internal Medicine.

Previous studies have shown that postoperative AF following noncardiac surgery confers increased risks for transient ischemic attack (TIA) and ischemic stroke. However, there is no information on how outcomes for postoperative AF after noncardiac surgery compare with those for AF occurring outside of the operative setting.

Against the above background, Konstantinos C. Siontis, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota, and colleagues aimed to compare the risks for ischemic stroke or TIA and other outcomes in patients with postoperative AF versus those with incident AF not associated with surgery in a cohort study.

The study included patients with incident atrial fibrillation between 2000 and 2013. They were categorized as having AF occurring within 30 days of a noncardiac surgery (postoperative AF) or having AF unrelated to surgery (nonoperative AF).

Findings of the Study

• Of 4231 patients with incident AF, 13% had postoperative AF as their first-ever documented AF presentation.
• Over a mean follow-up of 6.3 years, 486 patients had an ischemic stroke or TIA and 2462 had subsequent AF; a total of 2565 deaths occurred.
• The risk for stroke or TIA was similar between those with postoperative AF and nonoperative AF (absolute risk difference [ARD] at 5 years, 0.1%; hazard ratio [HR], 1.01).
• A lower risk for subsequent AF was seen for patients with postoperative AF (ARD at 5 years, −13.4%; HR, 0.68).
• No difference was seen for cardiovascular death or all-cause death between patients with postoperative AF and nonoperative AF.

The study is limited by the fact that the population consisted predominantly of White patients so caution should be used when extrapolating the results to more racially diverse populations.

The researchers conclude, "Our findings have potentially important implications for the early postsurgical and subsequent management of postoperative AF."

Reference

Siontis KC, Gersh BJ, Weston SA, Jiang R, Roger VL, Noseworthy PA, Chamberlain AM. Associations of Atrial Fibrillation After Noncardiac Surgery With Stroke, Subsequent Arrhythmia, and Death: A Cohort Study. Ann Intern Med. 2022 Jul 26. doi: 10.7326/M22-0434. Epub ahead of print. PMID: 35878404.