SPC365

Leadless Pacemakers in Dialysis Patients: How Do They Perform?

Session: Sessão de Posters 29 - Pacing sem elétrodos e inovação em dispositivos
Speaker: Fernando Nascimento Ferreira

Congress: CPC 2026
Topic: C. Arrhythmias and Device Therapy
Theme: 09. Device Therapy
Subtheme: 09.6 Device Therapy - Other
Session Type: Posters Eletrónicos
FP Number: ---
Authors: Fernando Nascimento Ferreira; Margarida Câmara Farinha; Sofia Jacinto; Ricardo Bernardo; Guilherme Portugal; Bruno Valente; Sónia Oliveira; André Viveiros Monteiro; Ana Lousinha; Pedro Silva Cunha; Rui Cruz Ferreira; Mário Oliveira

<p style="text-align:justify">&nbsp;</p>

<p style="text-align:justify"><span style="font-size:medium"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#000000"><strong><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Introduction: </span></span></strong><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Leadless pacemakers represent a major advancement in cardiac pacing, particularly for patients in whom traditional transvenous systems pose higher procedural and long-term risks. Individuals with end-stage renal disease (ESRD) on dialysis are especially vulnerable due to limited vascular access, central venous stenosis, and increased infection risk. By eliminating transvenous leads and subcutaneous pockets, leadless pacemakers reduce these complications while preserving venous integrity. However, data on their long-term electrical performance in dialysis patients remain scarce. Evaluating the evolution of pacing parameters&mdash;sensing amplitude, impedance, and capture threshold&mdash;is essential to confirm their reliability in this high-risk group. </span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:medium"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#000000"><strong><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Objective:</span></span></strong><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"> Evaluate the evolution of pacing parameters during the first year after leadless pacemaker implantation in patients under dialysis.</span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:medium"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#000000"><strong><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Methods: </span></span></strong><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">We conducted a retrospective two-centre cohort study including consecutive patients who underwent leadless pacemaker implantation between 2016 and 2025 under dialysis. Baseline clinical and procedural data were collected. Pacing parameters (sensing amplitude, impedance, and capture threshold) were recorded at implantation and during follow-up interrogations. Linear mixed-effects models were used to assess changes in pacing parameters over time.</span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:medium"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#000000"><strong><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Results: </span></span></strong><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">A total of 36 patients (mean age 71.8 &plusmn; 10,2 years, 31% female) were included. The majority (58,3%) had atrial fibrillation. Implantation was most frequently in the mid-septum (56%) using Micra VR (53%). At implantation, mean sensing was 7,6 mV (range 3,0&ndash;20,0), impedance 695 &Omega; (341&ndash;1620), and threshold 1.00 V @ 0.24 ms (0.38&ndash;2.75).During follow-up (median 335 days, (1&ndash;2533)), mixed-effects analysis showed no significant change in sensing (&beta; = +0.001 mV/day; 95% CI &minus;0.001 to +0.004; p = 0.275) and in capture threshold (&beta; </span></span><span style="font-size:10pt"><span style="font-family:Calibri,sans-serif">&asymp;</span></span><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"> 0.000 V/day; 95% CI 0.000&ndash;0.0001; p = 0.185). Conversely, impedance decreased significantly over time (&beta; = &minus;0.178 &Omega;/day; 95% CI &minus;0.293 to &minus;0.064; p = 0.003), corresponding to approximately &minus;5.4 &Omega; per month.</span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:medium"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#000000"><strong><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Conclusions: </span></span></strong><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">In dialysis patients, leadless pacemaker performance remained stable during the first year of follow-up, with preserved sensing and capture thresholds and a mild, expected decrease in impedance. These findings support the procedural and functional safety of leadless pacing in this high-risk population, although larger studies with longer follow-up are warranted to confirm long-term device stability and performance.</span></span></span></span></span></p>