Barcelona, Spain saw the convergence of world leaders and thinkers in cardiology to discuss the latest topics in contemporary cardiovascular care. There were many studies addressing atrial fibrillation (AF) and some potential “game-changers” made their debut as well.
Among them was CASTLE-AF, presented at the hotline sessions. The study garnered some attention as the only randomized controlled trial of catheter ablation vs pharmacologic therapy in patients with heart failure (HF) and AF that actually found a benefit in terms of “hard” outcomes (eg, death, heart failure hospitalization).
CASTLE-AF is the only RCT of catheter ablation vs drug therapy in patients with AF and HF to find benefit as measured by hard endpoints.
AF and HF are common co-morbid conditions and exacerbation of one can often worsen the other. Physicians struggle with how to best reduce the burden of AF – with either catheter ablation or pharmacologic therapy. This randomized trial, although small (N=397), had important implications and took over 9 years from enrollment to completion and screened ~3000 patients. The study enrolled patients with symptomatic paroxysmal or persistent AF, LVEF ≤35%, ICD with home monitoring capacity, NYHA Class 2 or worse, and failure of or intolerance to/reluctance to take anti-arrhythmic medication. Subjects were randomized to either radiofrequency catheter ablation (RF-ablation) with pulmonary vein isolation or conventional AF medical therapy after a run-in period.
The trial was positive based on both its primary (composite of all-cause mortality and heart failure hospitalization) and secondary (individual endpoints of all cause mortality, heart failure hospitalization, cardiovascular death, cardiovascular hospitalization) outcomes, as displayed in the Table. In addition to these hard outcomes, there was also a significant reduction in AF burden and an improvement in LVEF of 8% in the ablation arm.
Anti-arrhythmic (control) Group n=184
|HR (95% CI), p-value|
|Primary endpoint (composite
of all-cause mortality, HF hospitalization)
|28.5%||44.6%||0.62 (0.43-0.87), p=0.007|
(K-M curves started separating
|13.4%||25%||0.53 (0.32-0.86), p=0.011|
(K-M curves started separating
|20.7%||35.9%||0.56 (0.37-0.83), p=0.0004|
Adverse outcomes were mostly procedure-related and mostly confined to the ablation arm and included pericardial effusion (n=3), severe acute bleeding (n=3), pulmonary vein stenosis (n=1), groin infection (n=1), worsening heart failure (n=1), stroke/TIA (n=7 in ablation arm vs 12 in the conventional arm)
- Marrouche NF, Brachmann J, on behalf of CASTLE-AF Investigators. Catheter ablation versus standard conventional treatment in patients with left ventricular dysfunction and atrial fibrillation: The CASTLE-AF trial. European Society of Cardiology 2017 Congress. August 27, 2017, Barcelona, Spain.
- Di Biase L, Mohanty P, Mohanty S, et al. Ablation versus amiodarone for treatment of persistent atrial fibrillation in patients with congestive heart failure and an implanted device: Results from the AATAC multicenter randomized trial. Circulation 2016; 133:1637-1644.