# Clinical implications and recurrence rates of first-time catheter ablation for atrial fibrillation in hypertrophic cardiomyopathy: a nationwide cohort study

## TL;DR

This study finds that patients with hypertrophic cardiomyopathy have higher atrial fibrillation recurrence rates after catheter ablation compared to non-HCM patients, despite similar stroke and mortality rates.

## Contribution

The study provides real-world evidence on the effectiveness of catheter ablation for AF in HCM patients using a nationwide cohort.

## Key findings

- HCM patients had a 40% AF recurrence rate after 1 year compared to 30% in non-HCM patients.
- Heart failure risk was significantly higher in HCM patients (HR 2.45) after ablation.
- No significant differences in stroke or mortality rates were observed between HCM and non-HCM groups.

## Abstract

Catheter ablation (CA) for atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM) poses unique challenges due to structural and electrical remodelling. This study examines AF recurrence and complication rates following CA in HCM patients compared to a matched AF non-HCM cohort.

A retrospective cohort study of Danish nationwide registries from 2010 to 2022 was conducted. Rates of AF recurrence, heart failure, ischaemic stroke, and death were analysed using propensity score matching and Cox regression models. Among 28 231 patients undergoing first-time CA for AF, 299 had a confirmed diagnosis of HCM. Patients with HCM demonstrated significantly higher rates of AF recurrence compared to a matched non-HCM cohort, with 40% experiencing recurrence vs. 30% in the non-HCM group after 1 year and 67% vs. 58% after 5 years [hazard ratio (HR) 1.41, P < 0.001]. Despite the elevated recurrence rates, no significant differences were observed in the incidence of ischaemic stroke (HR 0.99, P & 0.9) or all-cause mortality (HR 1.18, P & 0.3). However, the risk of heart failure was significantly increased (HR 2.45, P & <0.001).

HCM patients experience higher AF recurrence rates post-CA as well as a higher risk of heart failure. These findings highlight the need for tailored strategies to improve outcomes in this high-risk group.