PO-05-052 COMPARISON OF SIMULTANEOUS, MATCHED PROGRAMMING AMBULATORY RHYTHM DETECTION BETWEEN A NOVEL EXTRAVASCULAR AND STANDARD TRANSVENOUS ICD SYSTEMS

Abstract

A novel extravascular (EV) ICD lead (AtaCor Medical, San Clemente, CA) is under development for sensing and defibrillation of ventricular tachyarrhythmias (VF) using commercial DF-4 compatible ICD pulse generators (PG). The purpose of this analysis is to perform a within-patient comparison of sensing and detection of ambulatory spontaneous cardiac rhythms between a novel EV-ICD system and a simultaneously implanted standard transvenous (TV) ICD system. In the non-randomized, single-center SECURE EV Study (NCT05099289), human subjects (n=18) were implanted with two ICD systems: (1) the Research EV-ICD system and (2) a standard TV-ICD system. The Research EV-ICD Lead was implanted into the anterior mediastinum and fixated at the fascial plane along the left parasternum. The EV-ICD lead was then tunneled subcutaneously to a left lateral pocket. The TV-ICD was implanted in standard fashion along the left or right subclavian with endocardial lead placement. The ICD pulse generators were programmed with matched sensitivity, detection zones and discrimination features to compare appropriate and inappropriate ambulatory sensing function. The EV-ICD systems were implanted for up to 90-days and were left in a “recording only” mode to store events without therapy delivery. Each implant system was interrogated over the 90- day study period to compare adjudicated stored events between the two systems. Matched and unmatched stored electrograms of appropriate and inappropriate episodes were valuated. The prototype EV-ICD lead placement was successful in 16/18 (89%) subjects. The median follow-up duration for the EV ICD lead was 90 days (mean = 71 days). During the follow up, spontaneous tachycardia events were stored in 7 (44%) subjects (2 patients with 3 matched appropriate events (Figure 1) and 5 patients with matched and unmatched inappropriate events). Two EV ICD subjects had unmatched inappropriate sensing events due to noise caused by a broken anode cable and another due to oversensing diaphragm myopotentials not seen by the TV ICD. Early experience with a prototype left, anterior parasternal EV ICD lead is highly correlative in automatically sensing and detecting cardiac rhythms such as VF using commercially available ICD PGs. Further iterations of the EV ICD lead should improve specificity.