EMBO-ABL: Cryoballoon non-inferior to radiofrequency catheter ablation for AF for silent cerebral events

By Lucas Marinacci on

Key Points:

  • Among AF patients undergoing catheter ablation, cryoballoon was non-inferior compared to radiofrequency for the primary endpoint of silent cerebral embolic events detected on MRI.

Catheter ablation (CA) for atrial fibrillation (AF) is associated with up to a 1% risk for thromboembolism and as high as 40% rate of silent cerebral embolism (SCE) detected on post-procedural imaging. There are two energy sources for CA: cryoballoon (CB) and radiofrequency (RF).  Whether the rates of embolic events differ by energy source is unknown.

On April 8, 2024, the principal results of the “A Multicenter Prospective Randomized Study Comparing the Incidence of Periprocedural Cerebral Embolisms Caused by Catheter Ablation of Atrial Fibrillation between Cryoballoon and Radiofrequency Ablation (Embo-Abl Study)” were presented at ACC Scientific Sessions 2024.  The purpose of this study was to compare the incidence of periprocedural cerebral embolism in CB vs RF ablation.

This prospective, open-label, non-inferior trial randomized patients planned for AF ablation to either CB or RF.  The primary endpoint was MRI-detected SCEs within 1 to 3 days of the procedure.  Of the 229 participants, the average age was 69, about 35% were female, and 8.7% in the CB group had  a previous stroke, compared to 2.6% in the RF group.  The rate of the primary endpoint of SCEs was 13.9% in the CB group and 9.7% in the RF group, with a risk difference of 4.18 (95% CI -4.18-12.5), and a p-value for non-inferiority of 0.02.  No other significant patient or procedural risk factors for SCEs were identified in this study.

Dr. Kengo Kusano of the National Cerebral and Cardiovascular Center, Japan, concluded: “In this prospective, multicenter, randomized, parallel-group, open-label study involving patients with AF who underwent CA, CB ablation demonstrated noninferiority to RF ablation in terms of the incidence of SCEs detected by brain DWI-MRI following the CA procedure.”