Effectiveness and safety of automatic capture management via remote monitoring system in left bundle branch area pacing

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: His-bundle pacing (HBP) and left bundle branch area pacing (LBBAP) have been popular as physiological pacing procedures and, according to previous reports, both can decrease heart failure admission and preserve left ventricular ejection fraction compared to right ventricular pacing. In general, the physiological pacing has different pacing thresholds (e.g. pacing thresholds of His-bundle or left bundle and myocardium), but automatic capture management cannot diagnose these multiple pacing thresholds and automatic adjustments of ventricular pacing output based on automatic ventricular threshold tests may not achieve the appropriate HBP or LBBAP. Especially in HBP, a fixed pacing output is likely to be recommended to ensure the definite HBP, since HBP thresholds tend to increase over the long term. PURPOSE: It has been reported that LBBAP thresholds are maintained lower than HBP thresholds. The aim of this study is to evaluate the safety and appropriateness of automatic capture management via a remote monitoring system in LBBAP patients. METHODS: Patients who underwent LBBAP from July 2019 to July 2022 were enrolled. The ventricular capture management used a 2x safety margin above the automatic ventricular pacing thresholds and a minimum pacing output of 2 V at 0.4 ms. Pacing thresholds were monitored using telemonitoring every month and pacing waveforms were evaluated during outpatient visits. RESULTS: Ninety patients with successful LBBAP were enrolled. LBBAP thresholds, R-wave amplitudes, and pacing impedances at implantation were 0.71±0.17 V at 0.4 ms, 16.4±6.7 mV, and 568±87.6 Ω, respectively, and the pacing QRS width was 128.8±16.8 ms. There was no significant difference between the pacing thresholds at the time of manual measurement during the outpatient visits and automatic measurement during the telemonitoring immediately before those visits, and all differences in pacing thresholds were less than 0.5 V at 0.4 ms. The median observation period was 481 days (range 215.75-685.5 days), and pacing thresholds, pacing outputs, and pacing QRS width at the last follow-up were 0.87 ± 0.30 V at 0.4 ms, 2.06 ± 0.21 V at 0.4 ms, and 129.3 ± 18.1 ms, respectively. One patient of lead dislodgement was detected 17 months after implantation and lead revision was performed. Another patient had a pacing threshold increase of more than 1V, but the function of automatic pacing output adjustment prevented pacing failure and LBBAP was maintained as well. CONCLUSIONS: Automatic capture managements in LBBAP could be accurately and safety managed with a remote monitoring system.