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

Background And 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 post-ablation are summarised here.

Methods: Patients with symptomatic paroxysmal atrial fibrillation underwent pulmonary vein isolation (PVI) 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-hour 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 utilisation was assessed as hospitalisation for cardiovascular events and antiarrhythmic drug (AAD) use.

Results: 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; 2 cardiac tamponades, 2 pulmonary vein stenosis, 1 anaphylactic shock). At 12 months, the overall AFEQT score increased by a median 26.9 points versus baseline. Cardiovascular hospitalisation rate reduced from 20.1% to 11.9% during the 12 months before versus after ablation, respectively. The use of Class I/III AAD decreased from 60.3% at baseline to 23.9% at 6 to 12 months post-ablation. 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 the 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.