SPC365

Non-conventional versus Conventional Pacing in Cardiac Amyloidosis: Impact on Clinical, Electrical, and Functional Outcomes

Session: SESSÃO DE POSTERS 06 - AMILOIDOSE CARDÍACA
Speaker: Maria Rita Lima

Congress: CPC 2025
Topic: F. Valvular, Myocardial, Pericardial, Pulmonary, Congenital Heart Disease
Theme: 17. Myocardial Disease
Subtheme: 17.4 Myocardial Disease – Treatment
Session Type: Cartazes
FP Number: ---
Authors: Maria Rita Giestas Lima; Rita Carvalho; Francisco Moscoso Costa; Sérgio Maltês; Gustavo Rodrigues; Pedro Galvão Santos; Pedro Carmo; Isabel Santos; Bruno Rocha; Carlos Aguiar; Diogo Cavaco; Pedro Adragão

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos,sans-serif"><strong><span style="font-family:&quot;Times New Roman&quot;,serif">Introduction</span></strong></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Times New Roman&quot;,serif">Cardiac amyloidosis (CA) is linked to conduction disturbances requiring pacing therapy, which includes conventional permanent pacemaker (PPM) or cardiac resynchronization therapy (CRT). Left bundle branch area pacing (LBBAP) is an alternative, offering physiological pacing. Limited evidence compares the outcomes of conventional (PPM) vs. non-conventional pacing (CRT or LBBAP) in CA. Thus, we aimed to evaluate these modalities of pacing in these patients. </span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos,sans-serif"><strong><span style="font-family:&quot;Times New Roman&quot;,serif">Methods</span></strong></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Times New Roman&quot;,serif">Single-centre retrospective study of consecutive CA patients who had a pacemaker implantation and classified as conventional (PPM group) and non-conventional pacing (CRT and LBBAP groups). Baseline clinical, laboratory, and echocardiographic data were collected pre- and post-implantation and differences were evaluated between groups. Basal ECG on routine ambulatory evaluation was used to measure baseline QRS intervals.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos,sans-serif"><strong><span style="font-family:&quot;Times New Roman&quot;,serif">Results</span></strong></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Times New Roman&quot;,serif">Among 312 CA patients, 50 (16%) received a device implantation (mean age 84&plusmn;6 years, 80% male, mean left ventricle ejection fraction [LVEF] 46&plusmn;13%): 32 (64%) underwent PPM, 12 (24%) CRT and 6 (12%) LBBAP. The primary indication for PPM was complete heart block (n=22), while CRT was primarily indicated for complete heart block and LVEF&lt;50% (n=5) and LBBAP for complete heart block (n=3). At baseline, CRT and LBBAP patients were more likely to have more symptoms of heart failure (p=0.049), complete LBBB (p=0.028), wider QRS (127&plusmn;25 <em>vs</em>. 156&plusmn;24 <em>vs.</em> 132 [104-147]ms for PPM/CRT/LBBAP, respectively; p=0.003) and more intraventricular desynchrony (p=0.001). Following implantation, pacing dependency was similar across all three groups during the follow-up (pacing percentage of 76&plusmn;31 <em>vs</em>. 98&plusmn;1 <em>vs</em>. 88&plusmn;9% for PPM/CRT/LBBAP, respectively; p=0.054). At a median follow-up of 24 months, CRT and LBBAP patients had more pronounced improvement in NYHA (p=0.005) (Figure 1A) and less intraventricular desynchrony (p=0.004). CRT patients had a greater reduction in QRS <span style="color:black">(+27 vs. </span>&ndash;<span style="color:black">8 vs. +24ms </span>for PPM, CRT and LBBAP, respectively; p=0.002) (Figure 1B). No significant differences were noted in NT-proBNP, LVEF or LV global longitudinal strain (Figure 1C-D). </span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos,sans-serif"><strong><span style="font-family:&quot;Times New Roman&quot;,serif">Conclusions</span></strong></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Times New Roman&quot;,serif">In a real-world cohort of patients with CA, the different pacing modalities were mostly applied according to guidelines recommendations. Accordingly, baseline features differed between groups, with patients undergoing CRT and LBBAP displaying markers of more severe disease. CRT was associated with an improvement in symptoms and LV desynchrony. LBBAP was associated with an increase in QRS duration similar to that observed in PPM, likely due to the infiltrative nature of CA and septal thickening, which may </span></span><span style="font-family:Calibri,sans-serif"><span style="font-family:&quot;Times New Roman&quot;,serif">compromise the LBBAP&nbsp;results.</span></span></span></p>