SPC365

Hypertrophic cardiomyopathy in a pediatric population

Session: CO 21 - Miocardiopatias
Speaker: Maria Inês

Congress: CPC 2021
Topic: K. Cardiovascular Disease In Special Populations
Theme: 30. Cardiovascular Disease in Special Populations
Subtheme: 30.3 Cardiovascular Disease in Special Populations: Pediatric Cardiology
Session Type: Comunicações Orais
FP Number: ---
Authors: Inês Araújo Oliveira; Isabel sá; Cláudia Falcão-Reis; Mariana Magalhães; Filipa Vila Cova; Marília Loureiro; Sílvia Álvares

<p style="text-align:justify"><span style="font-size:11pt"><span style="background-color:white"><span style="font-family:Calibri,sans-serif"><strong><span style="font-size:10.0pt"><span style="color:black">Introduction: </span></span></strong><span style="font-size:10.0pt"><span style="color:black">Hypertrophic cardiomyopathy (HCM), defined by an increased left ventricle wall thickness not solely explained by abnormal loading conditions, represents a heterogeneous group of disorders with a diversity that is more apparent in childhood than any other age. It can result from mutations in sarcomeric protein-coding genes, metabolic or neuromuscular diseases, drugs or chromosomal/monogenic syndromes. It can be associated with myocardial dysfunction, thromboembolic events and arrhythmias and is the main cause of sudden death (SD) in children.</span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="background-color:white"><span style="font-family:Calibri,sans-serif"><strong><span style="font-size:10.0pt"><span style="color:black">Aim: </span></span></strong><span style="font-size:10.0pt"><span style="color:black">To characterize the clinical evolution and outcome of the pediatric population with HCM followed in a tertiary hospital.</span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="background-color:white"><span style="font-family:Calibri,sans-serif"><strong><span style="font-size:10.0pt"><span style="color:black">Methods: </span></span></strong><span style="font-size:10.0pt"><span style="color:black">Retrospective review of patients&rsquo; records for clinical history, underlying conditions, risk factors, genetic tests, family history and evolution.</span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="background-color:white"><span style="font-family:Calibri,sans-serif"><strong><span style="font-size:10.0pt"><span style="color:black">Results: </span></span></strong><span style="font-size:10.0pt"><span style="color:black">Forty patients were included, 55% male. First evaluation was at a median age of 6,7 years. Echocardiography was performed in all patients and cardiac magnetic resonance in 50%. The most common cause was sarcomeric mutation (52,5%) and 71.4% were familial. The HCM was part of a syndromic etiology (Noonan, Opitz-Frias, Arthrogryposis) in 25%, of a metabolic disorder in 12,5% (mitochondrial cytopathy, Congenital disorder of glycosylation and Pompe disease), of Friedreich ataxia in 2,5%, and drug-induced in 2,5%. One patient had no identifiable cause for HCM. Bicuspid aortic valve (2.5%) and dysrhythmia were seen in patients with sarcomeric HCM. The most frequently mutated genes were </span></span><em><span style="font-size:10.0pt"><span style="color:black">MYBPC3</span></span></em><span style="font-size:10.0pt"><span style="color:black">, <em>MYH7</em>, <em>TNNT2</em>, <em>TNNI3</em>, <em>TPM1</em> and <em>MYL3</em>. </span></span><span style="font-size:10.0pt"><span style="color:black">One patient had a mutation related to left ventricular </span></span><span style="font-size:10.0pt"><span style="background-color:white"><span style="color:black">noncompaction</span></span></span><span style="font-size:10.0pt"><span style="color:black">. During follow-up, 72,5% of patients were under beta-blocker therapy, 15% required an implantable cardioverter-defibrillator, 5% had cardiac surgery and 2,5% had cardiac transplant. Five patients died: one SD with sarcomeric HCM, 4 with </span><span style="font-family:&quot;Calibri&quot;,sans-serif"><span style="color:black">HCM phenocopies</span></span><span style="color:black">. Mortality was greater when diagnosis occurred in the first year of life.</span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong><span style="font-size:10.0pt">Conclusions:</span></strong><span style="font-size:10.0pt"> HCM in children is a heterogeneous disease. The early diagnosis allows an adequate follow-up and identifies those at risk of adverse events. HCM associated to genetic syndromes or systemic diseases have poor prognosis. SD is rare. The clinical utility of defining the genotype in children with familial CMP exceeds that at other ages. Management of children requires special and individualized considerations. Genetic counselling is recommended and genetic and clinical screening of relatives should be offered. </span></span></span></p>