Esophageal Safety of High and Very High Power Short Duration Pulmonary Vein Isolation: a Randomized Comparison of the 50W and 90W Power Settings The HPSD Esophagus study

Abstract Background Point-by-point radiofrequency catheter ablation is commonly used for pulmonary vein isolation (PVI) in atrial fibrillation (AF). Very high power short duration (vHPSD) technology offers similar efficacy to high power short duration (HPSD) with reduced procedure times. A major complication of thermal ablation is atrioesophageal fistula (AEF), with esophageal lesions and gastroparesis indicating increased risk. A direct comparison of HPSD and vHPSD regarding thermal safety is lacking. Objective This randomized, single-center study aimed to compare the thermal safety of vHPSD to HPSD and identify anatomical and biophysical predictors of thermal injury (ClinicalTrials.gov ID: NCT06617442). Methods Patients undergoing first-time PVI for AF were randomized to either HPSD (50W) or vHPSD (90W). The study followed a noninferiority design, with the primary endpoint being a composite of esophageal mucosal lesion and gastroparesis, assessed via endoscopy within 15 days post-procedure. Pre-procedural CT scans were analyzed for anatomical risk factors. Results Among 100 patients (50 per group), the primary endpoint occurred in 7 (14%) of the vHPSD group and 6 (12%) of the HPSD group (estimated mean difference -2%, lower bound of 1-sided 95% CI -0.13), confirming non-inferiority. A smaller inter-lesion distance on the posterior wall was associated with increased risk (3.76 mm vs. 4.16 mm, p = 0.042). Conclusion Pulmonary vein isolation using 90W (vHPSD) applications was non-inferior to the 50W (HPSD) power setting in terms of esophageal safety. A smaller inter-lesion distance on the posterior wall was predictive of esophageal injury.