Key Points
- Evidence suggests that catheter ablation for atrial fibrillation (AF) is associated with improved cardiovascular outcomes compared to medical therapy in patients with heart failure (HF). However, its use in a population exclusively with end-stage HF eligible for heart transplant is unknown.
- The CASTLE-HTx trial demonstrated a significant decrease in a composite end-point of all-cause mortality, worsening of HF requiring a high urgent transplantation, or implantation of a ventricular assist device as bridge to transplantation therapy with atrial fibrillation ablation compared to medical therapy.
The case for catheter ablation for patients with advanced HF and AF was bolstered by the results of CASTLE-HTx, which were presented at the European Society of Cardiology 2023 annual conference with simultaneous publication in New England Journal of Medicine.
CASTLE-HTx was a single center, open-label trial conducted in Germany. Patients were randomized in a 1:1 ratio to undergo ablation or medical therapy (which included rate and rhythm control). This study evaluated whether ablation for AF was superior to medical therapy in patients with a left ventricular ejection fraction (LVEF) ≤ 35%, New York Heart Association Class 2 or greater, and eligible for heart transplant due to end-stage HF. The primary endpoint was the composite of all-cause mortality, worsening of HF requiring a high urgent transplantation, or implantation of a ventricular assist device as bridge to transplantation therapy.
A total of 97 patients were assigned to the ablation group and 97 to the medical therapy group. The trial was stopped for efficacy by the data and safety monitoring board 1 year after randomization was completed. The mean age was 64 years and 19% were female. Patients with both paroxysmal (30%) and persistent AF (56%) were included and approximately 56% patients had dual-chamber ICDs to assist in rhythm monitoring. Catheter ablation was performed in 81 of 97 patients (84%) in the ablation group and in 16 of 97 patients (16%) in the medical-therapy group. After a median follow-up of 18 months, the primary end-point event occurred in 8% of the ablation group and in 30% of the medical-therapy group (HR, 0.24; 95%, CI 0.11 to 0.52; P<0.001). Death from any cause was lower in the ablation group compared to medical therapy (HR, 0.09, 95%, CI 0.01-0.70; p<0.005).
The results of this trial align with the findings of the CASTLE-AF trial, published in 2018, which found that catheter ablation led to a significant reduction in death or hospitalization when compared to medical therapy in patients with AF and LVEF ≤ 35%.1 Dr. Christian Sohns from the Heart and Diabetes Center North Rhine-Westphalia (NRW) shared the results of the trial, summarizing that AF ablation should be considered part of the standard treatment for advanced HF patients awaiting transplant.
- Marrouche NF, Brachmann J, Andresen D, Siebels J, Boersma L, Jordaens L, Merkely B, Pokushalov E, Sanders P, Proff J, Schunkert H, Christ H, Vogt J, Bänsch D; CASTLE-AF Investigators. Catheter Ablation for Atrial Fibrillation with Heart Failure. N Engl J Med. 2018 Feb 1;378(5):417-427. doi: 10.1056/NEJMoa1707855. PMID: 29385358.