Leadless pacemaker performance short term outcomes
F Nascimento Ferreira, J Lopes, S Jacinto, R Bernardo, H Santos, G Portugal, B Valente, A Lousinha, P Osorio, P Silva Cunha, R Cruz Ferreira, M OliveiraAbstract
Introduction
Leadless pacemakers (LPM) have changed bradycardia management by eliminating transvenous leads and reducing device-related complications. A key determinant of procedural success and long-term device performance is the evolution of pacing capture thresholds, which should stabilize after implantation. Understanding the natural trajectory of LPM parameters and factors influencing their variation is essential to guide implantation strategy and follow-up management.
Objective
Evaluate the evolution of device parameters over time following implantation and assess which procedural factors influence threshold changes.
Methods
A retrospective cohort study included consecutive patients who underwent LPM implantation between 2016 and 2025 at a tertiary centre. Baseline clinical and procedural data were collected. Both parametric and non-parametric tests, including ANOVA and linear regression, were used to analyse threshold evolution and association with procedural variables. A p-value < 0.05 was considered statistically significant
Results
A total of 83 patients were included (mean age 74 ± 12 years, 33.7% female). Most procedures were performed in patients with atrial fibrillation (63%), and the majority were managed as outpatients (74.7%). All implantations were successful, predominantly located in the medium septum (60.2%) and apical septum (20.5%). There was one tamponade submitted to emergency surgery. The mean pacing threshold at implantation was 0.75V (range 0.20–3.25), which significantly decreased at the first interrogation [0.44 V (0.20–3.13), p = 0.005] and remained low at 1-month post-implantation [0.50 V (0.25–4.13), p = 0.003]. Impedance values declined over time (from 710 Ω to 570 Ω, p = 0.001), while sensing amplitude increased significantly (p = 0.003). No correlation was found between the presence of chronic kidney disease (CKD), implantation site, procedure duration or initial measured parameters and the evolution of device performance overtime.
Conclusion
LPM implantation demonstrated high procedural success with favourable electrical performance and a predictable decrease, followed by stability of pacing thresholds over time. The consistent trend toward threshold stabilization appeared independent of CKD, implantation site, procedure duration, or initial threshold, supporting the intrinsic maturation process at the electrode–myocardial interface.For image description, please refer to the figure legend and surrounding text.