Background: A novel QDOT MICRO (Biosense Webster, Inc., Irvine, CA) catheter with optimized temperature control and microelectrodes was designed to incorporate real-time temperature sensing with contact force detection and microelectrodes to streamline ablation workflow. The QDOT-MICRO feasibility study evaluated the workflow, performance, and safety of temperature-controlled catheter ablation in patients with symptomatic paroxysmal atrial fibrillation with conventional ablation setting. Methods: This was a non-randomized, single-arm, first-in-human study. The primary outcome was pulmonary vein isolation (PVI), confirmed by entrance block after adenosine and/or isoproterenol challenge. Safety outcomes included incidences of early-onset primary adverse events (AEs) and serious adverse device effects (SADEs). Device performance was evaluated via physician survey. Results: All evaluated patients (n = 42) displayed 100% PVI. Two primary AEs (4.8%) were reported: 1 pericarditis and 1 vascular pseudoaneurysm. An additional SADE of localized infection was reported in 1 patient. No stroke, patient deaths, or other unanticipated AEs were reported. Average power delivered was 32.1±4.1 W, with a mean temperature of 40.8°C±1.6°C. Mean procedure (including 20-minute wait), fluoroscopy, and radiofrequency application times were 129.8, 6.7, and 34.0 minutes, respectively. On device performance, physicians reported overall satisfactory performance with the new catheter, with highest scores for satisfaction and usefulness of the temperature indicator. Conclusions: Initial clinical experience with the novel catheter showed 100% acute PVI success and acceptable safety and device performance in temperature-controlled ablation mode. There were no deaths, stroke, or unanticipated AEs. Fluoroscopy and procedural times were short and similar or better than reported for prior generation catheters.

Department of Cardiology Aarhus University Hospital Palle Juul Jensens Boulevard 99 DK 8200 Aarhus N Denmark

Icahn School of Medicine at Mount Sinai 1 Gustave L Levy Pl New York NY 10029 USA

Institute for Clinical and Experimental Medicine Vídeňská 1958 9 140 21 Prague Czech Republic

Interventional Electrophysiology SCRIPPS Green Hospital San Diego CA 92037 USA

Jessa Ziekenhuis Virga Jesse Stadsomvaart 11 3500 Hasselt Belgium

Na Homolce Hospital Roentgenova 2 150 30 Prague 5 Czech Republic

OLV Hospital Cardiology Department Moorselbaan 164 9300 Aalst Belgium

Ospedale Generale Regionale F Miulli Strada Prov 127 70021 Acquaviva delle Fonti BA Italy

Texas Cardiac Arrhythmia Institute St David's Medical Center 3000 N IH 35 Suite 720 Austin TX 78705 USA

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