Long-Term Effects of Postoperative Atrial Fibrillation following Mitral Valve Surgery

Background: New-onset postoperative atrial fibrillation (PoAF) is one of the most frequent yet serious complications following cardiac surgery. Long-term consequences have not been thoroughly investigated, and studies have included different cardiac operations. The objectives were to report the incidence and short- and long-term outcomes in patients with PoAF after mitral valve surgery. Methods: This is a retrospective cohort study of 1401 patients who underwent mitral valve surgery from 2009 to 2020. Patients were grouped according to the occurrence of PoAF (n = 236) and the nonoccurrence of PoAF (n = 1165). Long-term outcomes included mortality, heart failure rehospitalization, stroke, and mitral valve reinterventions. Results: The overall incidence of PoAF was 16.8%. PoAF was associated with higher rates of operative mortality (8.9% vs. 3.3%, p < 0.001), stroke (6.9% vs. 1.5%, p < 0.001), and dialysis (13.6% vs. 3.5%, p < 0.001). ICU and hospital stays were significantly longer in patients with PoAF (p < 0.001 for both). PoAF was significantly associated with an increased risk of mortality [HR: 1.613 (95% CI: 1.048–2.483); p = 0.03], heart failure rehospitalization [HR: 2.156 (95% CI: 1.276–3.642); p = 0.004], and stroke [HR: 2.722 (95% CI: 1.321–5.607); p = 0.007]. However, PoAF was not associated with increased mitral valve reinterventions [HR: 0.938 (95% CI: 0.422–2.087); p = 0.875]. Conclusions: Atrial fibrillation after mitral valve surgery is a common complication, with an increased risk of operative mortality. PoAF was associated with lower long-term survival, increased heart failure rehospitalization, and stroke risk. Future studies are needed to evaluate strategies that can be implemented to improve the outcomes of these patients.