CMR-guided approach to localize and ablate gaps in repeat AF ablation procedure

Area of Science:

• Cardiology
• Medical Imaging
• Electrophysiology

Background:

• Atrial fibrillation (AF) recurrences after pulmonary vein isolation (PVI) can stem from gaps in ablation lines.
• Delayed-enhancement cardiac magnetic resonance (DE-CMR) imaging identifies these gaps, termed CMR gaps.

Purpose of the Study:

• To assess the feasibility and utility of a novel DE-CMR-guided strategy for ablating gaps during repeat AF ablation procedures.
• To compare the outcomes of DE-CMR-guided ablation with conventional methods.

Main Methods:

• Fifteen patients undergoing repeat AF ablations had pre-procedure 3D DE-CMR to create a detailed model.
• This DE-CMR model was used to guide ablation of identified CMR gaps, with operators blinded to electrical data.
• Conventional procedures in fifteen patients served as controls for procedural duration, radiofrequency, and fluoroscopy times.

Main Results:

• Sixty-seven CMR gaps were found around pulmonary veins and 9 at the roof line in the analyzed patients.
• A strong correlation was observed between electrically reconnected pulmonary veins and identified CMR gaps (79%).
• DE-CMR-guided ablation achieved reisolation in 95.6% of reconnected PVs and conduction block in all roof line cases, significantly reducing radiofrequency time compared to controls.

Conclusions:

• DE-CMR imaging is a feasible and effective tool for guiding repeat PVI procedures.
• The DE-CMR-guided approach accurately identifies and localizes gaps, potentially shortening procedure duration and radiofrequency application time.