SPC365

Low-activity alerts as a prognostic marker in ICD/CRT

Session: Sessão de Posters 20 - Gestão moderna de arritmias: do mapeamento à monitorização
Speaker: Inês Barroso Almeida

Congress: CPC 2026
Topic: C. Arrhythmias and Device Therapy
Theme: 09. Device Therapy
Subtheme: 09.4 Home and Remote Patient Monitoring
Session Type: Posters Eletrónicos
FP Number: ---
Authors: Inês Almeida; Margarida Câmara Farinha; Inês Coutinho dos Santos; Maria Inês Barradas; Fabiana Duarte; Luís Oliveira; Carina Machado; André Viveiros Monteiro; António Fontes; Nuno Pelicano; Miguel Pacheco; Emília Santos

<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-family:Calibri,sans-serif"><span style="color:black">Introduction: </span></span></strong><span style="font-family:Calibri,sans-serif"><span style="color:black">Remote monitoring of ICD/CRT devices allows continuous quantification of daily physical activity. Sustained reductions in activity (&ldquo;low burden activity&rdquo;) have been associated with worse outcomes, but national evidence remains scarce.</span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#000000"><strong><span style="font-family:Calibri,sans-serif"><span style="color:black"><span style="font-size:16px">Objective:</span> </span></span></strong><span style="font-family:Calibri,sans-serif"><span style="color:black"><span style="font-size:medium">To evaluate the association between low activity and a composite endpoint (urgent HF visit, HF hospitalization, stroke, ACS, and all-cause mortality) in ICD/CRT patients under remote monitoring</span><span style="font-size:x-small">.</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"><strong><span style="font-family:Calibri,sans-serif"><span style="color:black">Methods: </span></span></strong><span style="color:#000000; font-family:Calibri,sans-serif"><span style="color:black">We conducted a single-center cohort retrospective</span></span><span style="color:#000000; font-size:8pt">&nbsp;</span><span style="color:#000000; font-family:Calibri,sans-serif"><span style="color:black"> study of <strong>130</strong>&nbsp;<strong>patients</strong>. Low activity was defined as &lt;1 hour/day of physical activity; patients were divided into&nbsp;<strong>Group 1</strong>&nbsp;(low-activity alerts) and&nbsp;<strong>Group 2</strong>&nbsp;(no alerts). Proportional hazards were evaluated using a Cox model adjusted for age, sex, chronic kidney disease (CKD</span></span><span style="font-family:Calibri,sans-serif"><span style="color:black">), and device type (reference: transvenous ICD; comparators: CRT-P, CRT-D, and subcutaneous ICD). Due to missing data in some covariates, the multivariable analysis followed a complete-case approach (<strong>N=95</strong>).&nbsp;</span><span style="color:#000000">The mean follow-up was 8 years.</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-family:Calibri,sans-serif"><span style="color:black">Results: </span></span></strong><span style="font-family:Calibri,sans-serif"><span style="color:black">A total of 130 ICD/CRT patients were included, 63 with low-activity alerts and 64 controls. Most baseline characteristics were similar between groups, with no significant differences in sex, atrial fibrillation, coronary disease, hypertension, dyslipidemia, obesity, sleep apnea, psychiatric disease, malignancy, or smoking. Low-activity patients were older (72 vs. 62 years; p&lt;0.01) and had a higher prevalence of chronic kidney disease (30% vs. 10%; p&lt;0.01). Diabetes and prior malignancy were more common in this group but did not reach significance (both p&asymp;0.07). Device type differed between groups (p=0.04), with more CRT-P/CRT-D devices among low-activity patients and more transvenous ICDs in controls. NYHA class, LVEF, and other comorbidities were similar.</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"><span style="font-family:Calibri,sans-serif"><span style="color:black">Low activity was associated with a higher cumulative incidence of events (log-rank p=0.043). In the adjusted Cox model, low activity remained independently associated with the endpoint (<strong>HR 3.20; 95%CI 1.61&ndash;6.35; p=0.001</strong>). Female sex showed a borderline protective effect (<strong>HR 0.44; 95%CI 0.19&ndash;1.00; p=0.050</strong>). Among device types, CRT-D was independently protective (<strong>HR 0.33; 95%CI 0.15&ndash;0.72; p=0.006</strong>), while CRT-P and subcutaneous ICD were not significant. The overall model was significant (LRT &chi;&sup2;=28.3; df=7; p&lt;0.001), with a concordance statistic of&nbsp;<strong>0.696</strong>.</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-family:Calibri,sans-serif"><span style="color:black">Conclusion: </span></span></strong><span style="font-family:Calibri,sans-serif"><span style="color:black">A device-derived measure of &lt;1 hour/day of physical activity identifies ICD/CRT patients at higher risk of major cardiovascular events, even after multivariable adjustment. Remote monitoring may serve as an effective tool for early risk stratification and more targeted follow-up.</span></span></span></span></span></p>