Title: Derivation and validation of a VISITAG™-guided contact force ablation protocol for pulmonary vein isolation
Abstract: Abstract Aims Following radiofrequency (RF) pulmonary vein isolation (PVI), atrial fibrillation (AF) recurrence mediated by recovery of pulmonary vein (PV) conduction is common. I examined whether comparative VISITAG™ (Biosense Webster Inc.) data analysis at sites showing intra-procedural recovery of PV conduction versus acutely durable ablation could inform the derivation of a more effective VISITAG™-guided contact force (CF) PVI protocol. Methods and results Retrospective analysis of VISITAG™ Module annotated ablation site data in 10 consecutive patients undergoing CF-guided PVI without active VISITAG™ guidance. Employing 2mm positional stability range and lenient CF filter (force-over-time 10%, minimum 2g), inter-ablation site distance >10-12mm, adjacent 0g-minimum CF and short RF duration (3-5s) were associated with intra-procedural recovery of PV conduction. A VISITAG™-guided CF PVI protocol was derived employing ≤6mm inter-ablation site distances, minimum target ablation site duration ≥9s / force time integral (FTI) 100gs and 100% 1g-minimum CF filter. Seventy-two consecutive VISITAG™-guided CF PVI procedures were then undertaken using this protocol, with PVI achieved in all utilising 23.8[8.4] minutes total RF (30W, 48°C, 17ml/min, continuous RF application). Following protocol completion, acute intra-procedural spontaneous / dormant recovery of PV conduction requiring touch-up RF occurred in 1.4% / 1.8% of PVs, respectively. At 14[5] months’ follow-up in all 34 patients with paroxysmal AF ≥6 months’ post-ablation, 30 (88%) were free from atrial arrhythmia, off class I/III anti-arrhythmic medication. Conclusion VISITAG™ provides means to identify and then avoid factors associated with intra-procedural recovery of PV conduction. This VISITAG™ Module-guided CF PVI protocol demonstrated excellent intra-procedural and long-term efficacy. Condensed abstract Following CF-guided PVI, retrospective VISITAG™ Module analyses permitted the identification of ablation parameters associated with intra-procedural recovery of PV conduction. The derived VISITAG™ Module-guided CF PVI protocol employed short over RF duration yet proved efficient at achieving PVI acutely, with long-term follow-up demonstrating high clinical efficacy.