SPC365

Real-world performance of current sudden cardiac death risk models in Hypertrophic Cardiomyopathy: a single-centre study

Session: Sessão de Posters 18 - Miocardiopatia hipertrófica: genética, fenótipo e desfechos
Speaker: Helena Santos Moreira

Congress: CPC 2026
Topic: F. Valvular, Myocardial, Pericardial, Pulmonary, Congenital Heart Disease
Theme: 17. Myocardial Disease
Subtheme: 17.5 Myocardial Disease – Prevention
Session Type: Posters Eletrónicos
FP Number: ---
Authors: Helena Sofia Santos Moreira; Pedro Mangas Palma; Miguel Rocha; Catarina Marques; Mariana Vasconcelos; Elisabete Martins; Rui André Rodrigues; Ana Lebreiro

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Aptos,sans-serif"><strong><span style="font-size:11.0pt">Background: </span></strong><span style="font-size:11.0pt">Sudden cardiac death (SCD) risk stratification in hypertrophic cardiomyopathy (HCM) remains a cornerstone of disease management. However, currently available risk</span><span style="font-size:11.0pt"><span style="font-family:&quot;Cambria Math&quot;,serif">-</span></span><span style="font-size:11.0pt">prediction tools require refinement to balance the risks and benefits of implantable cardioverter-defibrillator (ICD) therapy.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Aptos,sans-serif"><strong><span style="font-size:11.0pt">Purpose: </span></strong><span style="font-size:11.0pt">To assess SCD risk and compare the performance of contemporary stratification strategies - namely the 2023 European Society of Cardiology (ESC) and 2024 American College of Cardiology/American Heart Association (ACC/AHA) flow-charts -&nbsp;in a real-world HCM population.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Aptos,sans-serif"><strong><span style="font-size:11.0pt">Methods: </span></strong><span style="font-size:11.0pt">Single-centre retrospective study of patients (pts) followed in a dedicated cardiomyopathy clinic with confirmed HCM. Pts with&nbsp;HCM mimics were excluded. Primary composite endpoint consisted of SCD, sustained ventricular arrhythmias and/or appropriate ICD therapies. Data was extracted from medical records.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Aptos,sans-serif"><strong><span style="font-size:11.0pt">Results: </span></strong><span style="font-size:11.0pt">A total of 130 HCM pts were included; 53.1% (n=69) were male, with mean age 62 &plusmn; 17 years. Obstructive phenotype was present in 22.3% (n=29), and pathogenic/likely pathogenic variants were identified in 33.8% (n=44). Based on clinician judgement and guideline-based risk stratification, 17.7% (n=23) received an ICD, predominantly for primary prevention (n = 19, 82.6%). </span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Aptos,sans-serif"><span style="font-size:11.0pt">At a median follow-up of 6 (IQR 8) years,&nbsp;6 pts (4.6%) reached the primary endpoint &ndash; 5 pts due to appropriate ICD shocks (of which, 3 pts where&nbsp;ICD carriers in a primary prevention setting with an estimated HCM-SCD risk score &gt; 6%) and 1 pt due to SCD. No inappropriate shocks in ICD-carriers&nbsp;were reported.&nbsp;</span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Aptos,sans-serif"><span style="font-size:11.0pt">When applied, the ESC 5-year HCM-SCD risk model was a significant predictor of events in Cox regression (HR 1.72; 95% CI 1.15&ndash;2.57; p = 0.009) and&nbsp; receiver operating characteristic (ROC) curve analysis yielded modest discrimination (AUC 0.623; 95% CI 0.309&ndash;0.937) &ndash; figure 1. </span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Aptos,sans-serif"><span style="font-size:11.0pt">In contrast, the ACC/AHA risk-marker&ndash;based algorithm did not differentiate event-free survival (log-rank p = 0.453), demonstrating limited discriminatory ability in our low-event-rate cohort.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Aptos,sans-serif"><strong><span style="font-size:11.0pt">Conclusions: </span></strong><span style="font-size:11.0pt">In our real-world HCM population, the ESC model demonstrated superior predictive performance and clinical utility compared with the ACC/AHA risk-marker approach, which was underpowered&nbsp;to detect differences in a population with predominantly low event rates. These findings underscore the need for improved and individualized SCD risk-prediction strategies in HCM.</span></span></span></p>