Data obtained recently demonstrates favourable effects on left ventricular ejection fraction (LVEF) and left ventricular dysfunction improvement following ablation for atrial fibrillation (AF) in patients with heart failure (HF). This study aimed to define the relationship between LVEF, and the endpoints of heart failure and mortality admissions in the CASTLE-AF study population.

The CASTLE-AF patients with juxtaposing AF (n=363) and HF were randomized in a multicenter prospective controlled fashion to pharmacological therapy (n=184) versus ablation (n=179). New York Heart Association class and left ventricular function and were evaluated at baseline and at each follow-up visit. In the ablation arm, a significantly higher number of patients experienced an improvement in their LVEF to >35% at the end of the study. Both ablation patient groups with moderate/severe or severe baseline LVEF had a lower number of cardiovascular hospitalizations, all-cause mortality, and composite endpoints. In the ablation group, NYHA I/II patients at the time of treatment had the most significant improvement in clinical outcomes.

In conclusion, AF ablation was associated with a significant improvement in LVEF as compared to pharmacological treatment; independent of the severity of left ventricular dysfunction. AF ablation should be performed at the early stages of the patient’s heart failure symptoms. HF populations with AF are highly heterogeneous, which can have a significant prognostic impact.