LEAP2: A first-in-human evaluation of a chronically implanted novel leadless pacemaker for conduction system pacing

In a first-in-human acute "pass-pull" study, we previously demonstrated that a novel leadless pacemaker (LP) for conduction system pacing (CSP) could acutely pace the deep interventricular septum (IVS).

This study aimed to evaluate the safety and efficacy of chronically implanted LP_CSP.

In this study, pacemaker-indicated patients received the Aveir-CSP leadless pacemaker (LP_CSP) as either a standalone ventricular pacemaker or as a dual-chamber system paired with an atrial LP. Introduced via the right internal jugular vein, the LP_CSP was implanted under fluoroscopic and intra-cardiac echocardiography guidance. The primary safety end point was complications at 1-month. Electrical performance (capture threshold at 0.4 ms, R-wave amplitude, impedance) and capture type (left bundle branch pacing [LBBP] vs left ventricular septal pacing [LVSP] vs deep septal pacing [DSP]) were assessed at implant and at 1 month.

Among 20 enrolled patients, 1 was withdrawn for challenging anatomy. LP_CSP implantation was successful in 18 of 19 patients: 4 ventricular-only and 14 dual-chamber. At implant, capture thresholds, R-wave amplitudes, and impedance were acceptable, and at 1 month, they were 1.3 ± 0.6 V, 13.1 ± 4.0 mV, and 490 ± 72 Ω, respectively. The capture type at implant was LBBP in 9, LVSP in 5, and DSP in 4 patients, but changed in 6 patients by 1-month follow-up. In addition, 3 patients had dislodgements. For dual-chamber implants, implant-to-implant communication was stable through 1-month. The 1-month LP_CSP complication-free-rate was 73.7%; 5 patients experienced complications, including internal jugular-access hematoma, LP_CSP dislodgements, and dislocation.

This first-in-human evaluation demonstrated the feasibility of leadless CSP, but improvements in LP_CSP stability fixation require further evaluation.