Postoperative atrial fibrillation as a marker of atrial myopathy in aortic stenosis: a prospective surgical cohort analysis
L Cristin, J Porterie, F Dagenais, N Ouidadi, V Stanova, C Laurin, M A Clavel, L TastetAbstract
Background
Postoperative atrial fibrillation (POAF) is frequent after cardiac surgery and is associated with adverse outcomes 1. After surgical aortic valve replacement (SAVR) for aortic stenosis, POAF may be particularly common, potentially reflecting an aortic stenosis-related atrial substrate beyond perioperative triggers alone 2. We compared the incidence, predictors, and prognostic implications of new-onset POAF after SAVR versus coronary artery bypass grafting (CABG).
Purpose
To (i) quantify the incidence and independent predictors of new-onset POAF after SAVR ±CABG using isolated CABG as comparator, and (ii) evaluate the association between POAF and long-term survival after each surgery.
Methods
In this prospective cohort study, consecutive adults undergoing cardiac surgery at a tertiary center (2013-2021) were screened (n=6,181). Patients with preoperative atrial fibrillation ([AF]; n=898), severe aortic regurgitation (n=281), or concomitant non-SAVR/non-CABG procedures (n=714) were excluded. The final cohort included 4,288 patients: SAVR group (n=1,830; isolated SAVR n=821; SAVR+CABG n=1,009) and isolated CABG (n=2,458). POAF was defined as new-onset AF or flutter within 30 days post intervention. Predictors were assessed by multivariable logistic regression. Long-term survival was evaluated by Kaplan-Meier and surgery-specific Cox proportional hazards model.
Results
Median age was 72 (66-77) years in the SAVR group (28% women) and 68 (61-64) years in the CABG group (22% women). POAF occurred in 1,881 (44%) patients and was more frequent after isolated SAVR (47.7%) and SAVR+CABG (52.7%) than isolated CABG (38.9%; p<0.001. Compared with CABG, SAVR remained independently associated with higher POAF risk (isolated SAVR: odds ratio [OR] 1.28, 95% CI 1.04-1.57, p=0.01; SAVR+CABG: OR 1.30, 95% CI 1.10-1.53, p=0.02). Additional predictors included age (OR 1.05 per year, 95% CI 1.04-1.06, p<0.001), female sex (OR 0.80; 95% CI 0.68-0.93, p=0.003), and red blood cell (RBC) transfusion (OR 1.05 per unit, 95% CI 1.00-1.09, p=0.03). POAF was associated with an increased risk of mortality in all groups (p<0.01). After adjustment for age, sex, EuroSCORE II, CHA2DS2-VA and perioperative RBC transfusion, POAF remained significantly associated with mortality in SAVR (isolated SAVR: hazards ratio [HR] 1.58; 95% CI 1.04-2.40, p=0.03 ; AVR+CABG: HR 1.46; 95% CI 1.10-1.94, p=0.008), but not after isolated CABG (HR 1.27, 95% CI 0.96-1.47; p=0.07).
Conclusions
In this study, SAVR conferred higher risk of new-onset POAF compared to isolated CABG, consistent with an intrinsic atrial susceptibility beyond shared perioperative stressors. POAF was independently associated with mortality after SAVR while not after isolated CABG. These findings support POAF as a marker for aortic stenosis-related atrial myopathy and suggest that intensified prevention and long-term surveillance, particularly after SAVR.Figure 1Figure 2