POAF duration modifies long-term stroke prediction by the CHA2DS2-VASc score after cardiac surgery
A Taseva, M Klincheva, G Boshevska, E Idoski, N Hristov, Z MitrevAbstract
Background
Postoperative atrial fibrillation (POAF) is the most common arrhythmia after cardiac surgery and is associated with thromboembolic and bleeding complications. Whether POAF duration modifies the prognostic performance of the CHA2DS2-VASc score remains unclear.
Purpose
To compare the early (in-hospital) and late (post-discharge) predictive value of the CHA2DS2-VASc score in patients with POAF lasting ≤48 hours versus >48 hours.
Methods
We conducted a retrospective single-center cohort study including consecutive adults who developed POAF after cardiac surgery between January 2020 and December 2023. POAF was defined as new-onset atrial fibrillation lasting >1 hour and/or requiring treatment. Outcomes were assessed during hospitalization, within 6 weeks, and beyond 6 weeks postoperatively. The CHA2DS2-VASc score was calculated for each patient and analyzed in relation to stroke occurrence. Endpoints included stroke (in-hospital, ≤6 weeks, and >6 weeks), clinically relevant bleeding, AF recurrence, and length of stay.
Results
Among 2,419 cardiac surgeries, 378 patients (16%) developed POAF (≤48 h: n=193; >48 h: n=185). POAF >48 hours were associated with higher in-hospital stroke rates (5.41% vs 1.55%), increased bleeding risk (OR 2.29; 95% CI 1.19–4.43), and longer hospitalization (10.8±5.66 vs 8.86±4.65 days; p<0.001). Within 6 weeks, stroke incidence was low and AF recurrence occurred in 12.5%, without significant between-group differences. The CHA2DS2-VASc score did not predict in-hospital stroke (p=0.859; p=0.994) or 6-week stroke (p=0.531). Beyond 6 weeks, the score was not predictive in the ≤48 h group (p=0.066), but independently predicted stroke in the >48 h group (OR 4.53 per point; 95% CI 1.44–14.28; p=0.010).
Conclusions
POAF lasting >48 hours identify a higher-risk subgroup with greater perioperative morbidity and prolonged hospitalization. The CHA2DS2-VASc score predicts late stroke only in patients with POAF >48 hours, suggesting that arrhythmia duration should be incorporated into postoperative thromboembolic risk stratification.