Association of coronary artery calcium with atrial arrhythmia recurrence after catheter ablation according to atrial fibrillation type

Background Coronary artery calcium (CAC) reflects systemic atherosclerosis and inflammation and may contribute to atrial remodeling. Although CAC has been associated with atrial arrhythmia recurrence after catheter ablation for atrial fibrillation (AF), whether this association differs according to AF type remains unclear. Methods and results We retrospectively analyzed 202 consecutive patients who underwent first-time catheter ablation for AF and had coronary computed tomography between October 2019 and August 2024. CAC was quantified using the Agatston score. The primary outcome was atrial arrhythmia recurrence beyond a 90-day blanking period. Patients were stratified by AF type, and associations were assessed using Kaplan–Meier analysis and Cox proportional hazards models. Branch-specific CAC was also evaluated in exploratory analyses. During a median follow-up of 617 days (IQR, 457–808), atrial arrhythmia recurrence occurred in 19 of 96 patients with paroxysmal AF (PAF; 19.8%) and 39 of 106 patients with non-PAF (36.8%). In the overall cohort, CAC ≥100 was associated with atrial arrhythmia recurrence after adjustment for age, sex, hypertension, diabetes mellitus, chronic kidney disease, and left atrial volume index (adjusted HR, 2.03; 95% CI, 1.07–3.86; P=0.031). In age- and sex-adjusted analyses stratified by AF type, CAC ≥100 was associated with a higher risk of recurrence in patients with PAF (adjusted HR, 5.59; 95% CI, 2.05–15.27; P<0.001), whereas no significant association was observed in patients with non-PAF (adjusted HR, 1.19; 95% CI, 0.56–2.52; P=0.647). The interaction between CAC ≥100 and AF type was statistically significant in the age- and sex-adjusted model (P for interaction=0.011) and remained significant in the expanded clinically adjusted model including hypertension, diabetes mellitus, chronic kidney disease, and left atrial volume index (P for interaction=0.005). Conclusions CAC ≥100 was associated with atrial arrhythmia recurrence after AF ablation, and this association may differ according to AF type, with a stronger association observed in patients with PAF. Subgroup and interaction analyses were exploratory and limited by the small number of recurrence events. CAC may provide useful information for post-ablation recurrence risk stratification, although these findings require validation in larger prospective studies.