Abstract 12783: Postoperative Cardioversions for New-onset Atrial Fibrillation in Cardiac Surgery

Abstract

Introduction: New-onset postoperative atrial fibrillation (AF) is a frequent complication after open-heart surgery and cardioversions (CV) are often performed to restore sinus rhythm in this setting. Thromboembolic risk related to early postoperative CV and the recurrence of AF in the long-term follow-up, however, remain largely unknown. Hypothesis: The FIN-bioAVR study sought to assess the rate of strokes and transient ischemic attacks (TIA) shortly after CV for AF in patients who underwent isolated aortic valve replacement with bioprosthesis. Methods: Between 2002 and 2014, 784 patients underwent isolated aortic valve replacement with a bioprosthesis in four Finnish University Hospitals. Results: During postoperative hospitalization when patients with prior chronic AF were excluded, 368/685 (53.7%) of patients had at least one new-onset paroxysm of AF (median time to diagnosis 3 [3] days), and early CV was performed in 122/368 (33.2%) of them. Baseline characteristics were comparable except that patients with CV had more often prior diagnosis of heart failure and less often chronic lung disease compared to those without CV. Hospital stay was significantly shorter, but at two-weeks follow-up, the rate of stroke/TIAs was 3.3% vs. 0.4% (p=0.05) in those with vs. without CV, respectively. Strikingly, early CV was associated with a trend of increased risk of two-week stroke/TIA rate compared to patients without CV (OR 7.66 (95%-CI 0.85-69.3, p=0.07)). In the median follow-up of 1682 [1514] days patients with early CV had more often recurrences of clinical AF (57% vs. 39%, p<0.01). Conclusions: In this large real-world population of patients undergoing aortic valve bioprosthesis operation, the rate of new-onset in-hospital AF was over 50%. Nearly third of them had a CV and these patients had over 7-fold risk for thromboembolisms related to CV.