Atrial fibrillation ablation in patients with hypertrophic cardiomyopathy: Findings and outcomes of repeat ablation procedures.

BACKGROUND: Patients with atrial fibrillation (AF) and hypertrophic cardiomyopathy (HCM) commonly require repeat catheter ablation procedures for AF management. The mechanisms underlying the increased AF recurrence rates are poorly defined. OBJECTIVE: We aimed to explore mapping findings and ablation outcomes among patients with HCM undergoing repeat AF ablation. METHODS: In this single-center study, 45 patients with HCM underwent repeat AF ablation procedures (2015-2023). Patients were age- and sex-matched 1:1 to control patients without HCM undergoing repeat AF ablation. Details from comprehensive electroanatomic mapping were compared. Univariate and multivariate Cox regression analyses were used to evaluate prognostic factors for recurrent AF in HCM. RESULTS: The mean age in the HCM group was 57.5 ± 13.2 and 71% were male. The most common finding at repeat ablation was pulmonary vein (PV) reconnection (86.7% in the HCM group vs 75.5% in the control group, P = .34). Patients were followed for a median of 456 days (interquartile range 127-1148). 26 patients (57.8%) in the HCM group experienced recurrent AF during the follow-up period, compared with 23 patients (51.1%) in the control group (P = .52). No significant difference in AF recurrence was found between the 2 groups (log-rank P = .33). Left atrial volume index and early AF recurrence during the blanking period were both associated with AF recurrence in univariate analyses; however, these were not significant in multivariate analysis. CONCLUSION: PV reconnection is commonly observed in patients with HCM undergoing repeat AF ablation. Repeat AF ablation outcomes in patients with HCM were comparable to those in patients without HCM.