Pacing therapy for immune checkpoint inhibitors-associated atrioventricular block: a single-center cohort study.

Background: ICI-associated myocarditis is an uncommon yet potentially fatal condition, particularly when concomitant with atrioventricular block (AVB) necessitating pacing. The role of pacing therapy for ICI-associated AVB remains unknown.

Objectives: The aim of this study is to investigate the efficacy and safety of pacing therapy for ICI-associated AVB.

Methods: Patients with ICI-associated myocarditis admitted to Peking Union Medical College Hospital from May 1st 2019 to April 30th 2024 were consecutively screened and the patients with AVB requiring pacing therapy were retrospectively included. Baseline clinical characteristics and initial temporary pacing therapy were evaluated. Follow-up assessments were conducted to evaluate the survival rate and the recovery of atrioventricular conduction.

Results: A total of 43 patients with ICI-associated myocarditis were screened. Among them, a total of 11 (11/43, 25.6%) patients (mean age 64.5 ± 8.6 years, female 18.2%) were diagnosed with advanced or complete AVB and subsequently underwent pacing therapy. Short-term (within 90-days after procedure) survival rate was 72.7% (8/11). Atrioventricular conduction recovered in 4 (4/11, 36.4%) patients, without AVB recurrence after temporary pacemaker removal. For safety endpoints, right ventricular (RV) pacing parameters including pacing threshold, sensing amplitude and impedance were acceptable and no procedure-related complications occurred except RV temporary active fixation lead dislodgement in 1 patient (1/11, 9.1%). No pacing system related-infection occurred.

Conclusions: Pacing therapy for ICI-associated AVB demonstrates both safety and efficacy. ICI-associated AVB shows a high rate of recovery. Temporary pacemaker with active fixation lead may be a reasonable option for the initial pacing therapy.