Associations between new-onset postoperative atrial fibrillation and long-term outcome in patients undergoing surgical aortic valve replacement.

OBJECTIVES: Data on prognostic implications of new-onset postoperative atrial fibrillation (POAF) after surgical aortic valve replacement (SAVR) is limited. We sought to explore associations between POAF, early-initiated oral anticoagulation (OAC), and long-term outcome after SAVR and combined SAVR+CABG.

METHODS: This is a retrospective, population-based study including all isolated SAVR (n = 7038) and combined SAVR and CABG patients (n = 3854) without a history of preoperative atrial fibrillation in Sweden 2007-2017. Individual patient data was merged from four nationwide registries. Inverse Probability of Treatment Weighting (IPTW) adjusted Cox regression models were employed separately in SAVR and SAVR+CABG patients. Median follow-up time was 4.7 years (range 0-10 years).

RESULTS: POAF occurred in 44.5% and 50.7% of SAVR and SAVR+CABG patients, respectively. In SAVR patients, POAF was associated with increased long-term risk of death [adjusted hazard ratio (aHR) 1.21 (95% confidence interval 1.06-1.37)], ischaemic stroke [aHR 1.32 (1.08-1.59)], any thromboembolism, heart failure hospitalization, and recurrent atrial fibrillation. In SAVR+CABG, POAF was associated with death [aHR 1.31 (1.14-1.51)], recurrent atrial fibrillation, and heart failure, but not with ischaemic stroke [aHR 1.04 (0.84-1.29)] or thromboembolism. OAC was dispensed within 30 days after discharge to 67.0% and 65.9% respectively of SAVR and SAVR+CABG patients with POAF. Early initiated OAC was not associated with reduced risk of death, ischaemic stroke or thromboembolism in any group of patients.

CONCLUSIONS: POAF after SAVR is associated with an increased risk of long-term mortality and morbidity. Further studies are warranted to clarify the role of OAC in SAVR patients with POAF.