Outcome of New-Onset Postoperative Atrial Fibrillation After Cardiac Surgery in Adults With Congenital Heart Disease

Background: Postoperative atrial fibrillation (POAF) is one of the most common complications after cardiac surgery. POAF is associated with a longer hospital stay, higher healthcare resource utilization, and higher risk of morbidity and mortality. As a result, the American and European guidelines recommend the use of beta-blockers and amiodarone for the prevention of POAF, and in turn, avoid the complications associated with POAF. Objectives: The purpose of this study was to determine the incidence, risk factors, and prognostic implications of new-onset POAF after cardiac surgery in adults with congenital heart disease (CHD). Methods: A retrospective study was conducted among adults with CHD who underwent cardiac surgery (2003-2019). POAF and late-onset atrial fibrillation (AF) were defined as AF occurring within and after 30 days postoperatively, respectively. Results: Of 1,598 patients (mean age 39 ± 13 years, 51% men), 335 (21%) developed POAF. Risk factors associated with POAF were older age, hypertension, left atrial (LA) reservoir strain and right atrial (RA) dysfunction, and nonsystemic atrioventricular valve regurgitation. Of 1,291 patients (81%) with follow-up ≥12 months, the annual incidence of late-onset AF was 1.5% and was higher in patients with POAF compared with those without POAF (5.9% vs 0.4%; P < 0.001). Risk factors associated with late-onset AF were POAF, older age, severe CHD, and LA and RA dysfunction. Of the 1,291 patients, 63 (5%) died during follow-up, and the risk factors associated with all-cause mortality were older age, severe CHD, hypertension, left ventricular systolic dysfunction, and LA and RA dysfunction. POAF was not associated with all-cause mortality. Conclusions: POAF was common in adults with CHD and was associated with late-onset AF but not all-cause mortality. Atrial dysfunction was independently associated with POAF, late-onset AF, and all-cause mortality. These risk factors can be used to identify patients at risk for POAF and provide a foundation for prospective studies assessing the efficacy of prophylactic therapies in this population.