Abstract 4138230: Incidence of Worsening Tricuspid Regurgitation Following Implantation of Leadless versus Dual-Chamber Pacemakers

Introduction: Cardiac implantable electronic devices (CIED) may result in or worsen tricuspid regurgitation (TR), which is associated with a higher risk of morbidity and mortality ( Figure 1 ). However, the incidence of TR following implantation of leadless pacemakers versus dual-chamber pacemakers (DC-PPM) is not well described. Hypothesis: Micra leadless pacemakers will have a lower incidence of worsening TR relative to standard DC-PPMs. Aims: To evaluate the incidence of worsening TR after implantation of leadless and DC-PPMs. Methods: We performed a retrospective study of all patients who underwent Micra leadless pacemaker or DC-PPM implantation at the University of California, San Diego from 2/2019-2/2024. The primary outcome was incidence of worsening TR. Results: A total of 476 patients underwent CIED implantation with both pre- and post-echocardiograms completed, of which 26.9% (n=128) had a Micra leadless pacemaker implanted and 73.1% (n=348) had a DC-PPM implanted. The average time to first post-implantation echocardiogram was 359 days in the Micra group and 510 days in the DC-PPM group (p=0.004). Worsening TR post-CIED implantation occurred in 21.9% (n=28) of patients who had a Micra and 25.9% (n=90) of patients who had a DC-PPM (p=0.192). The TR worsened by an average of 0.88 ± 0.32 grades in the Micra group versus 0.98 ± 0.33 grades in the DC-PPM group (p=0.08). Conclusion: In this analysis, leadless pacemaker implantation was associated with a statistically insignificant trend towards less TR. However, the degree of worsening TR following leadless pacemaker or DC-PPM implantation is relatively mild and of unclear clinical significance.