Long-Term Outcome of Catheter Ablation for Atrial Fibrillation in Patients With Apical Hypertrophic Cardiomyopathy.

Abstract

Atrial fibrillation (AF) is a common manifestation in cases of hypertrophic cardiomyopathy (HCM). Catheter ablation (CA) for AF in patients with asymmetric septal HCM (SeHCM) is selectively effective and often needs a repeat procedure. Apical HCM (ApHCM) has a better prognosis than SeHCM. However, the outcome of CA for AF in patients with ApHCM is unclear. Eighteen patients with ApHCM (ApHCM group) and 13 SeHCM patients (SeHCM group) underwent CA for AF. Ninety sex-, age-, and AF type-matched non-HCM patients who underwent CA for AF were selected as controls (5 controls for each ApHCM patient). During a median follow-up of 44.7 ± 30.8 months, 50% of the patients remained free from AF/atrial tachycardia (AT) in the ApHCM group. The ApHCM patients displayed enlarged left atrial (LA) diameter (47.1 ± 6.0 mm vs.42.4 ± 5.5 mm, P = 0.006) and increased E/Ea ratio (13.5 ± 4.4 vs. 9.1 ± 3.1, P < 0.001) as compared to the control group. In contrast, the mean LA diameter and E/Ea ratio of the ApHCM group were not different than those of the SeHCM group. The overall freedom from AF/AT in the ApHCM group was significantly worse than in the control group (log rank P = 0.028), but there was no difference between the ApHCM and SeHCM groups (P = 0.831). High LA diameter index ≥25 mm/m(2) (HR 12.8, 95% CI [1.2-142.1]; P = 0.037) was an independent predictor of AF/AT recurrence among patients with ApHCM. Long-term outcome of CA for AF was worse in patients with ApHCM, as compared to controls, but was similar to patients with SeHCM.