Preoperative Atrial Fibrillation and Cardiovascular Outcomes After Noncardiac Surgery

Background: The impact of pre-existing atrial fibrillation (AF) on outcomes after noncardiac surgery is not clear.

Objectives: We aimed to study the impact of AF on the risk of adverse outcomes after noncardiac surgery in a nationwide cohort.

Methods: We identified Medicare beneficiaries admitted for noncardiac surgery from 2015 to 2019 and divided the study cohort into 2 groups: with and without AF. Noncardiac surgery was classified into vascular, thoracic, general, genitourinary, gynecological, orthopedics and neurosurgery, breast, head and neck, and transplant. We used propensity score matching on exact age, sex, race, urgency and type of surgery, revised cardiac risk index (RCRI) and CHA₂DS₂-VASc score, and tight caliper on other comorbidities. The study outcomes were 30-day mortality, stroke, myocardial infarction, and heart failure. We examined the incremental utility of AF in addition to RCRI to predict adverse events after noncardiac surgery.

Results: The study cohort included 8,635,758 patients who underwent noncardiac surgery (16.4% with AF). Patients with AF were older, more likely to be men, and had higher prevalence of comorbidities. After propensity score matching, AF was associated with higher risk of mortality (OR: 1.31; 95% CI: 1.30-1.32), heart failure (OR: 1.31; 95% CI: 1.30-1.33), and stroke (OR: 1.40; 95% CI: 1.37-1.43) and lower risk of myocardial infarction (OR: 0.81; 95% CI: 0.79-0.82). Results were consistent in subgroup analysis by sex, race, type of surgery, and all strata of RCRI and CHA₂DS₂-VASc score. AF improved the discriminative ability of RCRI (C-statistic 0.73 to 0.76).

Conclusion: Pre-existing AF is independently associated with postoperative adverse outcomes after NCS.