Po-05-027 incidence of pacing-induced cardiomyopathy and need for cardiac resynchronization therapy upgrade in patients with leadless pacemaker: long term follow-up of 75 patients

Excessive right ventricular (RV) pacing with traditional pacemaker has been associated with a 17-25% risk of pacing-induced cardiomyopathy (PICM), defined as a decrease of left ventricular ejection fraction by 10% or more. The risk of PICM with more septally placed leadless pacemaker is unknown. We aimed to report the incidence of PICM in patients with leadless pacemaker and the need for cardiac resynchronization therapy (CRT) upgrade. We performed a single-center analysis of patients who underwent leadless pacemaker implantation between January 1, 2014 and April 1, 2022. Patient echocardiogram result pre and post implantation were collected. The outcomes of this study included the incidence of PICM in leadless pacemaker implant patient, the rate of CRT upgrade, RV pacing percentage, total RV pacing time and follow up duration. The definition of total RV pacing time was the duration from pacemaker to last follow up multiplied by RV pacing percentage. A total 75 patients underwent leadless-pacemaker implantation were included in this study. The mean age was 80 ± 8.5 year-old. Indications for single chamber leadless implantation include sick sinus syndrome and bradycardia. Mean duration of follow up was 14.6 months. The RV pacing percentage was 64.4 ± 38.58 %.The mean RV pacing time was 9.2 ± 1.4 months, PICM was found in 32 patients (44%), 10 patients (13.5%) required CRT upgrade due to congestive heart failure symptoms. The mean duration between implantation of leadless pacemaker to upgrade CRT was 372 ± 489.8 days. The incidence of PICM in leadless pacemaker patients was 44% and 13.5 % of patients required CRT upgrade within 2 years after the leadless pacemaker implant in the majority of the patients. Further studies are necessary to confirm these findings.