Incidence of systolic heart failure and need for implantable cardiac defibrillators in patients with atrial fibrillation who had catheter ablation versus antiarrhythmic medical therapy

Abstract Background The CASTLE-AF trial demonstrated that patients with atrial fibrillation (AF) and heart failure with reduced ejection fraction (HFrEF) who underwent catheter ablation (CA) showed improved patient outcomes. These outcomes included a reduction in all-cause mortality and heart failure hospitalizations along with an improvement in left ventricular ejection fraction, when compared to those receiving medical therapy alone. However, there is no data regarding development of novel HFrEF and the need for implantable cardiac defibrillator (ICD) in patients with AF who underwent CA vs. those on antiarrhythmic therapy (AAD). Purpose This study aims to assess if there is a difference in the development of HFrEF and the need for ICD intervention amongst AF patients who underwent CA vs. those on AAD. We hypothesize that patients with AF who underwent CA will have a decrease in the development of HFrEF and mitigation in the need for ICD intervention compared to AAD alone. Methods A large retrospective, multicentre database was utilized to identify patients aged 18-80 with AF from 2017-2023. Two cohorts were subsequently established based on treatment received: 1) CA vs. 2) AAD (amiodarone, flecainide, dronedarone, dofetilide, propafenone, sotalol). Patients with crossover between the groups were excluded. Student’s t-test was performed to compare baseline characteristics between cohorts. Relevant comorbidities, atrial fibrillation types, and cardiovascular medications were used for propensity matching. Kaplan Meier curves were calculated to compare outcomes at 5 years such as HFrEF development, ICD implantation, mortality, and hospitalizations. Results Patients that underwent CA (n=32,774) and AAD (n=345,882) were propensity matched yielding 32,670 patients per cohort. CA demonstrated a significantly decreased need for ICD intervention compared to AAD (1.69% vs. 3.28%; HR=0.559; 95% CI [0.503, 0.621], log rank p<0.0001). Secondary outcomes showed significant reduction in development of systolic heart failure (4.83% vs. 10.60%; HR=0.499; 95% CI [0.467, 0.533], log rank p<0.0001), overall hospitalizations (12.03% vs. 27.32%; HR=0.440; 95% CI [0.420, 0.461], log rank p<0.0001), and all-cause mortality (2.38% vs. 14.19%; HR=0.188; 95% CI [0.174, 0.203], log rank p<0.0001) with catheter ablation. Conclusions Patients that underwent CA had a significant reduction in development of systolic heart failure and mitigation in the need for ICD implantation when compared to those on AAD alone. Randomized clinical trials are needed to better understand this relationship and to further define which subpopulation of atrial fibrillation patients would derive the most benefit from CA.