High efficacy single catheter standardized workflow for radiofrequency ablation of atrial fibrillation in the high-power short-duration era

Abstract

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Dr. Valeriano and Dr. Fabbricatore have been supported by a research grant provided by the Cardiopath PhD program (University of Naples Federico II) Background Recent developments in radiofrequency (RF) ablation technologies have improved the efficacy of pulmonary vein isolation (PVI). The combination of the ablation index, lesion tags, and optimized inter-lesion distance (CLOSE protocol) has further reduced the incidence of gaps along the ablation lines. This high acute success rate challenged the use of conventional circular mapping catheters and prompted a single catheter-approach ablation strategy. Modulating the relationship between resistive and conductive heating, high-power short-duration (HPSD) ablation technology can potentially increase lesion-to-lesion consistency. A novel catheter with optimized temperature control and microelectrodes has been recently designed to further improve workflow efficiency. Purpose: This study aimed to assess the efficacy and efficiency of HPSD ablation in a standardized single-catheter workflow for PVI. Methods: Data on consecutive AF ablations performed with HPSD catheter from December 2020 to December 2021 at a single tertiary-care center were prospectively collected. The workflow consisted of a procedure sequence including single transeptal access with a bidirectional steerable sheath, 3D modeling with 3D rotational angiography, assessment of PV potentials with microelectrodes in each vein (figure 1), followed by radiofrequency encircling of the PVs using a high-power setting of 50W in a temperature- and flow-controlled mode with CLOSE-guided protocol. Isolation was validated by reassessing the previously observed PV potentials and by pacing within the lesion set. Results: A total of 73 consecutive AF patients (67% paroxysmal, 33% persistent) were included. All patients received PVI, 15 underwent additional cavotricuspid isthmus ablation and 6 received additional treatments (table 1). Mean procedure time was 68±27 min with minimal fluoroscopy time and dose (3.2±2.1 min; 4.7±3.9 Gycm2). Complications were infrequent with 1 cardiac tamponade and 1 pericarditis. First-pass isolation was achieved in 91% of the circles and validation by microelectrodes successfully identified the residual gaps with 100% of acute procedural success. In a selected cohort of 20 patients with paroxysmal AF undergoing PVI-only procedure performed by an expert operator, the ablation time was 22.8±5.1 min with a skin-to-skin time of 47.3±7.1 min (table 2). The median follow-up duration was 397 days (IQR: 367-462). AT/AF free survival rate was 90% at 12 months. Conclusions: HPSD ablation using a standardized single-catheter workflow improved the procedural efficiency of PVI and resulted in a high rate of first-pass isolation with a low recurrence rate at 12-month follow-up.