Dual energy for pulmonary vein isolation using focal ablation technology integrated with a three-dimensional mapping system: SmartfIRE 12-month results.

Aims: The multicentre, single-arm SmartfIRE study assessed the safety and effectiveness of the novel dual-energy THERMOCOOL SMARTTOUCH SF (DE STSF) contact-force sensing catheter with multimodality generator to deliver radiofrequency (RF) and unipolar biphasic pulsed field (PF) ablation. Three-month follow-up showed a 100% acute success rate with an acceptable safety profile. Results at 12 months postablation are summarized here.

Methods and results: Patients with symptomatic paroxysmal atrial fibrillation underwent pulmonary vein isolation with the recommendation of PF ablation at posterior/inferior and RF ablation at the anterior/ridge/carina segments. The 12-month effectiveness endpoint was freedom from documented symptomatic and asymptomatic atrial arrhythmia on or off antiarrhythmic therapy (assessed by electrocardiogram, remote arrhythmia monitoring, and 24-h Holter), including acute procedural failures. Safety was assessed as the incidence of serious adverse events (SAEs) related to device and/or procedure. Quality of life was evaluated via Atrial Fibrillation Effect on Quality-of-Life (AFEQT) scores, and healthcare utilization was assessed as hospitalization for cardiovascular events and antiarrhythmic drug (AAD) use. Of 149 patients enrolled, 140 had the study catheter inserted (safety population analysis set), and 136 met the eligibility criteria and had ablation energy delivered (per-protocol analysis set). Freedom from symptomatic and asymptomatic atrial arrhythmia at 12 months was 71.5% (84.2% when using standard-of-care monitoring only). The clinical success rate (freedom from symptomatic arrhythmia) was 86.4%, and single procedural success was 81.0% (n = 136). The rate of device- and/or procedure-related SAEs was 3.6% (5/140 patients; two cardiac tamponades, two pulmonary vein stenosis, one anaphylactic shock). At 12 months, the overall AFEQT score increased by a median 26.9 points vs. baseline. Cardiovascular hospitalization rate reduced from 20.1 to 11.9% during the 12 months before vs. after ablation, respectively. The use of Class I/III AAD decreased from 60.3% at baseline to 23.9% at 6-12 months postablation. Post hoc analysis showed that patients with high adherence to recommended inter-tag distance and PF/RF index during ablation (n = 47) had a 12-month freedom from atrial arrhythmia recurrence of 86.9%, while the remaining patients (n = 88) had a rate of 64.0%.

Conclusion: The 12-month follow-up of the SmartfIRE study demonstrated the effectiveness, safety, and healthcare benefits of ablation using the DE STSF platform.

Clinical trial registration: ClinicalTrials.gov Identifier: NCT05752487(https://clinicaltrials.gov/study/NCT05752487).