Pulmonary vein encirclement using an Ablation Index-guided point-by-point workflow: cardiovascular magnetic resonance assessment of left atrial scar formation.

Louisa O’Neill,Steven E Williams,Orod Razeghi,Iain Sim,Matthew Wright,Rahul K Mukherjee,John Whitaker,Tevfik Ismail,James Harrison,Rashed Karim,Mark D O’Neill,Steven Niederer

doi:10.1093/europace/euz226

Louisa O’Neill, Steven E Williams + Show 10 more

Open Access

https://doi.org/10.1093/europace/euz226

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Abstract

Aims A point-by-point workflow for pulmonary vein isolation (PVI) targeting pre-defined Ablation Index values (a composite of contact force, time, and power) and minimizing interlesion distance may optimize the creation of contiguous ablation lesions whilst minimizing scar formation. We aimed to compare ablation scar formation in patients undergoing PVI using this workflow to patients undergoing a continuous catheter drag workflow.Methods and resultsPost-ablation cardiovascular magnetic resonance imaging was performed in patients undergoing 1st-time PVI using a parameter-guided point-by-point workflow (n = 26). Total left atrial scar burden and the width and continuity of the pulmonary vein encirclement were determined on analysis of atrial late gadolinium enhancement sequences. Comparison was made with a cohort of patients (n = 20) undergoing PVI using continuous drag lesions. Mean post-ablation scar burden and scar width were significantly lower in the point-by-point group than in the control group (6.6 ± 6.8% vs. 9.6 ± 5.0%, P = 0.03 and 7.9 ± 3.6 mm vs. 10.7 ± 2.3 mm, P = 0.003). More complete bilateral pulmonary vein encirclements were seen in the point-by-point group (P = 0.038). All patients achieved acute PVI.ConclusionPulmonary vein isolation using a point-by-point workflow is feasible and results in a lower scar burden and scar width with more complete pulmonary vein encirclements than a conventional drag lesion approach.

Highlights

Despite ongoing technological advances in catheter ablation for atrial fibrillation (AF), single procedure success rates remain modest
Post-ablation cardiovascular magnetic resonance imaging was performed in patients undergoing 1st-time pulmonary vein isolation (PVI) using a and results parameter-guided point-by-point workflow (n = 26)
Total left atrial scar burden and the width and continuity of the pulmonary vein encirclement were determined on analysis of atrial late gadolinium enhancement sequences

Summary

Introduction

Despite ongoing technological advances in catheter ablation for atrial fibrillation (AF), single procedure success rates remain modest. Conducting gaps in the pulmonary vein encirclement are consistently identified as a cause of arrhythmia recurrence[1] and ablation lesion transmurality and contiguity are major determinants of electrically conducting gaps.[2,3] The Ablation Index Webster) is a real-time lesion assessment index incorporating contact force (CF), time, and power in a weighted formula. Ablation Index has been shown in canine studies to predict lesion depth[4] and in humans to identify sites of pulmonary vein reconnection at repeat.

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