Safety and feasibility of a novel multielectrode array catheter in mapping atrial and ventricular arrhythmias with high density: results from the multicenter OPTIMUM study

Abstract

The OPTRELL (Biosense Webster) multielectrode array mapping catheter includes 48 electrodes symmetrically distributed on 6 splines. A unique feature is an additional unipolar reference electrode (TRUERef, Biosense Webster) located in the distal end of the irrigation lumen, serving as an internal close unipolar reference electrode to reduce far-field unipolar signals. The catheter provides visualiza-tion of real-time conduction vectors for better understanding of beat-by-beat wave propagation over the catheter surface, showing the direction of most significant change in local activation times and highlighting areas of slow conduction and scarring. An enhanced bipolar mapping module enables selection of the measurement either along or across the splines, whichever best conforms with wave propagation. Studies in a swine model demonstrated the ability of this catheter to provide high-density and high-resolution mapping in complex substrates [1, 2]. We aimed to assess the safety and mapping performance of the catheter and navigation system for mapping the atria and ventricles in patients with various complex arrhythmias. The OPTIMUM study (ClinicalTrials.gov Identifier: NCT04983797) was a prospective, a multicenter, a single-arm, and an open-label study. Participants with scar-related atrial tachycardia (AT), paroxysmal or persistent atrial fibrillation (PAF or PsAF), ventricular tachycardia (VT), or premature ventricular complexes (PVCs) underwent preab-lation mapping with the study catheter (Fig. 1), followed by standard-of-care ablation. Primary safety endpoint was 7-day incidence of device-related serious adverse events (SAEs), and primary effectiveness endpoint was completion of protocol-required fast activation and electro anatomical preablation mapping without resort to nonstudy mapping catheter(s). Physicians' assessment of deployment, maneuverability , and signal quality were obtained from a post-procedure survey using a 1-7 Likert scale (1 = poor and 7 = excellent). Between August 25 and October 26, 2021, 31 participants were enrolled and mapped (9 for scar-related AT, 12 for PAF, 1 for PsAF, 6 for VT, and 3 for PVC). Mean ± standard deviation (SD) age was 59.8 ± 14.4 years and 71% were male. Mean ± SD duration of preablation mapping was 29.9 ± 17.8, 20.0 ± 20.0, and 26.7 ± 8.8 min for AT, PsAF, and PAF, respectively, and 122.2 ± 43.9 and 51.3 ± 28.3 min for VT and PVC, respectively; mean total procedural time was 101.2 ± 32.5, 170.0, 102.5 ± 24.9, 223.7 ± 53.1, and 185.0 ± 25.5 min, respectively. Fast anatomical mapping was performed for all participants. Voltage mapping was performed in all redo-PAF, PsAF, and VT procedures and most AT and PVC procedures. Local activation-time mapping was most often performed for AT, VT, and PVC procedures. No SAEs were related to the study catheter. Three participants reported 4 SAEs unrelated to the study catheter (pseudoaneurysm, hematoma, bladder catheter site injury, and anemia). All participants recovered or resolved at follow up. There were no occurrences of cardiac perforation, thromboembolic events, catheter entanglement with cardiac structure, or device malfunction. Primary effectiveness end-point was achieved in 100% of participants. Almost all operators rated highly (≥ 5) on noise reduction in bipolar maps (30/31 operators) and short learning curve (27/31 operators). Operators rated the study catheter highly