Impact of single atrial fibrillation catheter ablation onimplantable cardioverter defibrillator therapies in patients with ischaemic and non-ischaemic cardiomyopathies

Aims Atrial fibrillation (AF) is associated with frequent appropriate and inappropriate implantable cardioverter defibrillator (ICD) therapies. Catheter ablation of AF has been shown to reduce AF burden and improve left ventricular function in heart failure patients but the impact on ICD therapies has not yet been studied. The aim of this study was to test the hypothesis that AF ablation reduces ICD therapies in patients with cardiomyopathies. Methods and results In 73 consecutive patients (mean age 59 +/- 10 years, 85% male) with previously implanted ICD due to ischaemic (n = 30) or dilated cardiomyopathy (n = 43) undergoing AF ablation, the prevalence and frequency of ICD therapies before and after AF ablation were compared. During the total follow-up of 3.3 +/- 3 years prior to AF ablation, 5.1 +/- 14.7 therapies per patient-yearwere delivered as opposed to 1.8 +/- 10.9 in a period of 1.1 +/- 0.9 years after ablation (P = 0.002). Prior to AF ablation, 39 patients (53%) received at least one ICD therapy when compared with 15 patients (21%) after ablation. Atrial fibrillation ablation was associated with freedom from any therapy regardless of appropriateness (odds ratio, OR, 0.366, CI 0.164-0.816, P = 0.014, adjusted for follow-up). Appropriate shocks significantly decreased from 0.3 +/- 1.3 to 0.1 +/- 0.5 per patient-year (P = 0.030). While heart failure medication and use of antiarrhythmic drugs were comparable during the entire follow- up, a statistically significant improvement of left ventricular ejection fraction (LVEF) from 36.9 +/- 12.3% to 40.7 +/- 6.7% (P = 0.008) was observed after AF ablation. Conclusions In patients with ischaemic or dilated cardiomyopathy, catheter ablation of AF is associated with the reduction of inappropriate and appropriate ICD therapies and improvement of LVEF.