OBJECTIVETo evaluate the efficacy of catheter ablation in Chinese hypertrophic cardiomyopathy (HCM) patients with atrial fibrillation (AF), and to determine the risk factors of AF recurrence.

METHODSThis study enrolled 40 HCM patients with AF who underwent primary AF ablation at Beijing Anzhen Hospital from June 2005 to June 2013. Ablation strategy included bilateral pulmonary vein isolation (PVI) for paroxysmal AF (n = 27) and PVI plus left atrial roof, mitral isthmus and tricuspid isthmus linear ablations for persistent AF (n = 13). AF recurrence was followed-up by means of electrocardiography or Holter monitoring. Risk factors associated with AF recurrence were determined by a Cox regression model and the predictive power was evaluated by receiver operating characteristic (ROC) curve.

RESULTSAfter (34 ± 18) months follow-up, 30% (12/40) cases remained in sinus rhythm off antiarrhythmic drug, most AF recurrence (18/28, 64.3%) occurred within 1 year post ablation. Multivariate Cox regression demonstrated that left atrial dimension (LAD, HR = 1.124, 95% CI 1.051-1.202, P = 0.001) and female gender (HR = 3.304, 95% CI 1.397-7.817, P = 0.007) were independent risk factors of AF recurrence. The cut-off value of LAD at 43.5 mm predicted AF recurrence with sensitivity of 93.5% and specificity of 60.0%. Every 1 mm enlargement in LAD was associated with an increased risk of arrhythmia recurrence (HR = 1.095, 95% CI 1.031-1.163, P = 0.003).

CONCLUSIONSAF ablation in Chinese HCM patients is safe and feasible. However, sinus rhythm maintenance rate is low at long-time follow-up. Most of the recurrent AF occurs within 1 year post AF ablation procedure. Left atrial diameter and female gender are independent risk factors of AF recurrence.