LAUSR

Background: Atrial fibrillation catheter ablation (AFCA) success rates vary across different phenotypes of hypertrophic cardiomyopathy (HCM). Therefore, we compared long-term outcomes between apical (aHCM) and septal (sHCM) subtypes of HCM. Methods: This retrospective study analyzed patients with HCM who underwent AFCA at the First Affiliated Hospital of Nanjing Medical University between January 2010 and December 2020. Results: A total of 36 patients with aHCM and 80 patients with sHCM were enrolled. During a median follow-up of 42 months (interquartile range (IQR) 18–83), the overall atrial tachyarrhythmia (ATa) recurrence rate after a single ablation was 42.2% (49/116). The aHCM patients had a higher ATa recurrence rate than the sHCM patients (58.3% vs. 35.0%; χ2 = 5.54; p = 0.019). The ATa recurrence risk increased by 94% in patients with aHCM (hazard ratio (HR) 1.94, 95% confidence interval (CI) 1.10–3.43; log-rank p = 0.021). Subgroup analysis demonstrated pronounced risk elevation in paroxysmal atrial fibrillation (AF) patients (HR 2.85, 95% CI 1.44–5.67; p = 0.003), while no intergroup difference was observed in patients with persistent AF (HR 0.90, 95% CI 0.31–2.62; p = 0.853) (interaction p = 0.080). Multivariate Cox regression analysis identified antiarrhythmic drug (AAD) use (HR 0.22, 95% CI 0.08–0.59; p = 0.003), hypertension comorbidity (HR 2.50, 95% CI 1.21–5.19; p = 0.014), persistent AF type (HR 0.41, 95% CI 0.17–1.00; p = 0.049), and left atrial diameter ≥45 mm (HR 2.55, 95% CI 1.11–5.85; p = 0.028) as independent predictors of postoperative recurrence. Conclusions: An aHCM subtype predicts higher ATa recurrence after a single ablation versus sHCM. Hypertension, a left atrial enlargement ≥45 mm, and no AAD use are independent predictors of recurrence. Meanwhile, optimizing blood pressure and AAD therapy may improve outcomes.