Ablation of accessory pathways in different anatomic locations using focal pulsed field ablation.

BACKGROUND: Ablation of accessory pathways (APs) is the cornerstone for treatment of patients with Wolff-Parkinson-White syndrome and manifestation of atrioventricular reentrant tachycardia. Pulsed field ablation (PFA) is a new type of nonthermal energy source delivered to the underlying tissue via the ablation catheter and used for ablation of arrhythmic substrates. OBJECTIVE: The purpose of this study was to determine the efficiency and long-term outcome of ablation of APs of different localizations using a focal pulsed electrical field. METHODS: Electrophysiological study was performed in patients with indication for AP ablation. An ablation catheter was used to map the position of AP insertion. Pulsed electric field was delivered through a standard ablation catheter. In left-sided APs, the first ablation attempt was within the coronary sinus (CS). Patient follow-up was scheduled 1-3 months after the ablation. Additional check-up was performed after 6 and 12 months. RESULTS: Fourteen 14 patients (3 pediatric) were treated. Termination of AP conduction was achieved in all procedures. The cohort consisted of 3 right free wall, 3 posteroseptal, and 8 left-sided APs. Ablation through CS was successfully used in 7 of 8 patients with left-sided APs. No complications were reported. Median follow-up was 5.5 months. Conduction recurrence through AP was documented in 1 patient. CONCLUSION: Focal PFA for AP shows promising results in terms of efficacy and safety. A high rate of successful termination of left-sided APs by ablation within CS may represent a new standard approach. The safety and efficacy profile of PFA seems to be transferable to the pediatric population.

Diagnostic and therapeutic pathways for the malignant left atrial appendage: European Heart Rhythm Association physician survey.

AIMS: Patients with atrial fibrillation who despite taking oral anti-coagulant therapy (OAT) suffer a stroke or systemic embolism (SSE) without vascular cause or who develop left atrial appendage (LAA) thrombus (LAAT) should be considered as having malignant LAA. The optimal treatment strategy to reduce SSE risk in such patients is unknown. The aim of the study is to investigate the diagnostic and therapeutic pathways for malignant LAA practiced in European cardiac centres. METHODS AND RESULTS: An 18-item online questionnaire on malignant LAA was disseminated by the European Heart Rhythm Association (EHRA) Scientific Initiatives Committee. A total of 196 physicians participated in the survey. There seems to be high confidence in transoesophageal echocardiography (TEE) imaging, considering LAAT diagnosis. Switching to another direct oral anti-coagulant (DOAC) is the preferred initial step for the treatment of malignant LAA followed by a switch to vitamin K antagonist (VKA), low-molecular-weight heparin, or continued/optimized DOAC dosage, whereas LAA closure is the last option. Left atrial appendage closure is a viable option in patients with embolic stroke despite OAT and no evidence of thrombus at TEE (empty LAA) after comprehensive diagnostic measures to exclude other sources of embolism. CONCLUSION: This EHRA survey provides a snapshot of the contemporary management of patients diagnosed with malignant LAA. Currently, the majority of patients are treated on an outpatient basis with either shifting from VKA to DOAC or from one DOAC to another. Left atrial appendage closure in this population seems to be reserved for patients with higher bleeding risk or complications of malignant LAA, such as stroke.

Pulsed field ablation using focal contact force-sensing catheters for treatment of atrial fibrillation: acute and 90-day invasive remapping results.

AIMS: Pulsed field ablation (PFA) has emerged as a promising alternative to thermal ablation for treatment of atrial fibrillation (AF). We report performance and safety using the CENTAURI™ System (Galvanize Therapeutics) with three commercial, focal ablation catheters. METHODS AND RESULTS: ECLIPSE AF (NCT04523545) was a prospective, single-arm, multi-centre study evaluating safety and acute and chronic pulmonary vein isolation (PVI) durability using the CENTAURI System in conjunction with the TactiCath SE, StablePoint, and ThermoCool ST ablation catheters. Patients with paroxysmal or persistent AF were treated at two centres. Patients were analysed in five cohorts based upon ablation settings, catheter, and mapping system. Pulsed field ablation was performed in 82 patients (74% male, 42 paroxysmal AF). Pulmonary vein isolation was achieved in 100% of pulmonary veins (322/322) with first-pass isolation in 92.2% (297/322). There were four serious adverse events of interest (three vascular access complications and one lacunar stroke). Eighty patients (98%) underwent invasive remapping. Pulsed field ablation development Cohorts 1 and 2 showed a per-patient isolation rate of 38% and 26% and a per-PV isolation rate of 47% and 53%, respectively. Optimized PFA Cohorts 3-5 showed a per-patient isolation rate of 60%, 73%, and 81% and a per-PV isolation rate of 84%, 90%, and 92%, respectively. CONCLUSION: ECLIPSE AF demonstrated that optimized PFA using the CENTAURI System with three commercial, contact force-sensing, solid-tip focal ablation catheters resulted in transmural lesion formation and high proportion of durable PVI with a favourable safety profile, thus providing a viable treatment option for AF that integrates with contemporary focal ablation workflows.