Fluoroless Workflow for Pulsed Field Ablation of Atrial Fibrillation Using the Sphere-9 and VARIPULSE Catheters

Vollständiger Abstract

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Background: Catheter ablation is the most effective rhythm-control strategy for symptomatic atrial fibrillation (AF). A fluoroless approach eliminates ionizing radiation exposure for patients, operators, and laboratory staff and removes the ergonomic burden of leaded protective garments. Pulsed field ablation (PFA) is a predominantly non-thermal energy modality with a distinct safety profile, now addressed in dedicated international consensus documents. Several PFA catheters are natively integrated with three-dimensional electroanatomical mapping (3D EAM) platforms and are therefore well suited to fluoroscopy-free workflows. This review is confined to two of them—Sphere-9 (Affera/Medtronic) and VARIPULSE (Biosense Webster)—with which the authors have direct procedural experience. Objective: This study seeks to describe a practical, expert- and experience-based approach to zero-fluoroscopy AF ablation with these two catheters, to review the harms of radiation exposure, and to synthesize the currently available and still limited evidence for fluoroless PFA. The workflow presented is explicitly not an evidence-validated or broadly generalizable algorithm, and each procedural step is labeled according to whether it rests on comparative data, device-specific studies or instructions for use, or institutional practice and expert opinion. Methods: This is a structured narrative review. PubMed/MEDLINE was searched to 30 June 2026 (final search 30 June 2026), with no lower date restriction, using controlled vocabulary and free-text terms for atrial fibrillation, catheter ablation, zero or minimal fluoroscopy, pulsed field ablation, Sphere-9, Affera, and VARIPULSE. English-language randomized trials, cohorts, registries, systematic reviews, and society documents reporting procedural or clinical outcomes were eligible; reference lists were hand-searched. Conference abstracts, preprints, and non-peer-reviewed manufacturer reports were excluded from all numerical statements. Results: Four meta-analyses report comparable acute success, arrhythmia recurrence, and complication rates between zero-fluoroscopy and fluoroscopy-guided AF ablation, with procedural feasibility of 95.1% and a crossover rate of 1.26%. These are pooled observational comparisons without pre-specified non-inferiority designs or margins, and they should not be read as establishing formal non-inferiority. Differences between them reflect ablation technology, imaging strategy, study period, operator experience, and heterogeneous definitions of “zero fluoroscopy”. Randomized evidence comparing PFA with thermal ablation shows comparable 12-month efficacy and major complication rates and shorter procedure duration but no consistent reduction in fluoroscopy time—a finding that bears directly on the present topic. Sheath visualization is the decisive enabler: in a randomized trial of 100 patients, left atrial fluoroscopy time was 0 s (IQR 0–0) with a visualizable steerable sheath. In a nonrandomized subgroup analysis of the AdmIRE trial, 12-month freedom from AF was similar across zero- (72.1%), low- (75.4%) and conventional-fluoroscopy (73.6%) strategies. Conclusions: Integration of PFA with 3D EAM and intracardiac echocardiography makes a fluoroless workflow practical in experienced hands. The supporting evidence remains predominantly observational; no randomized trial has compared zero-fluoroscopy with fluoroscopy-guided PFA, and the approach described here should be regarded as expert practice rather than a standard of care. Patient safety, not the absolute avoidance of fluoroscopy, must remain the governing principle.