Dual-energy contact force-sensing focal ablation catheter for repeat ablation of persistent atrial fibrillation or atrial tachycardia after prior atrial fibrillation ablation
N Johner, F Notaristefano, J L Fitzgerald, M Tetreault-Langlois, G Ditac, K Vlachos, C Monaco, B Sacristan, J Charton, R Tixier, J Duchateau, F Sacher, P Jais, T Pambrun, N DervalAbstract
Background
A novel dual-energy contact force-sensing focal ablation catheter (DE-STSF) integrated with a three-dimensional mapping system was recently shown to be safe and effective for de novo pulmonary vein isolation (PVI) in paroxysmal atrial fibrillation (AF). There is, however, scarce clinical experience with repeat ablation, persistent AF and non-PV lesions.
Purpose
The objective was to describe our early experience with DE-STSF regarding the safety and acute efficacy of repeat ablation for persistent AF or atrial tachycardia (AT) following prior AF ablation.
Methods
A single-centre observational study was conducted on consecutive patients who underwent repeat ablation with DE-STSF for recurrent persistent AF or AT following prior AF ablation. Electroanatomical mapping was performed at baseline to identify gaps in previous linear lesions. The ablation strategy consisted in (redo) PVI combined with linear lesions targeting: the mitral isthmus (with vein of Marshall ethanol infusion), the posterior wall, the cavotricuspid isthmus (CTI) and, depending on previous lesions, box isolation of the posterior wall (roof and floor line), a partial anterior left atrial (LA) line anchored to the mitral annulus ("anterior hemi-line"), superior vena cava (SVC) isolation, and a bicaval line transecting the posteroseptal right atrium. Radiofrequency (RF) (35-45W, 10-20g, 7-25 sec) was preferentially delivered at anterior LA sites, the mitral isthmus and the CTI. Pulsed field ablation (PFA) (24 pulses, 10-20g) was preferentially delivered at posterior LA sites and non-CTI right atrial sites.
Results
A total of 22 patients (68% male, 65.1±18.3 years) were included. The median number of prior AF ablations was 2 (interquartile range 1-3). The recurrent arrhythmia was persistent AF in 14 (64%) patients and AT in 8 (36%). At baseline, 8/22 (36%) patients exhibited ≥1 PV reconnection. Among prior linear lesions, residual conduction was present across the roof line in 8/20 (40%) patients, the mitral line in 6/19 (31%), the floor line in 5/10 (50%), the CTI in 4/19 (21%) and the anterior hemi-line in 1/3 (33%). The table below summarizes the lesion set performed at repeat ablation and acute endpoints. PFA (alone or combined with RF) was used for all 8 redo PVIs (with 100% acute isolation), all 13 floor lines (92% acute block), all 7 bicaval lines (86% acute block) and all 4 SVC isolations (100% acute isolation). Notably, 3 patients showed RF-refractory floor line conduction at prior procedures; PFA-only ablation upon redo achieved first-pass block in all 3. Conscious sedation with midazolam and opioids was used in 15 (68%) patients with good tolerance. No major complications occurred.
Conclusion
The DE-STSF ablation catheter appears to be a safe, effective and versatile option for repeat procedures after prior AF ablation. PFA allowed to safely achieve redo PVI, floor line block, bicaval line and SVC isolation, with good tolerance under conscious sedation.