Postoperative atrial fibrillation is associated with long-term morbidity and mortality in older adults: Analysis from the SWEDEHEART Registry

Objectives: Postoperative atrial fibrillation (POAF) is the most common perioperative arrhythmia. The association of POAF with negative short-term outcomes after cardiac surgery is well understood; however, the association of POAF with long-term morbidity and mortality is not well described. We compared the risk of long-term clinical outcomes (up to 9 years postdischarge) in patients with and without POAF following open-chest cardiac surgery. Methods: This observational, retrospective cohort study used data from the Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies (SWEDEHEART) Swedish Cardiac Surgery Registry and National Board of Health and Welfare. Patients aged 55 to 90 years who underwent open-chest coronary artery bypass and/or valvular surgery between 2010 and 2019 were included. Clinical outcomes were adjusted for differences in baseline demographics and clinical history using multivariable Cox regression. Results: A total of 30,870 patients with a mean age of 69.2 years were included in the study (no POAF, n = 20,734; POAF, n = 10,136). The median follow-up was 4.6 years. After adjustment, POAF was associated with a significantly higher risk of recurrent atrial fibrillation (hazard ratio [HR], 2.30; 95% CI, 2.21-2.41), heart failure (HR, 1.17; 95% CI, 1.10-1.25), chronic kidney disease (HR, 1.15; 95% CI, 1.07-1.24), all-cause mortality (HR, 1.11; 95% CI, 1.04-1.18), and cardiovascular mortality (HR, 1.16; 95% CI, 1.06-1.26). POAF was also associated with a numerically higher risk of ischemic stroke and major bleed, but these findings were not statistically significant after adjustment. Conclusions: These data provide further insight into the long-term clinical outcomes associated with POAF in patients undergoing cardiac surgery.