SPC365

Desmoplakin cardiomyopathy: a rare new entity mimicking recurrent acute myocarditis

Session: Casos Clínicos: Insuficiência Cardíaca e Cuidados Intensivos Cardíacos
Speaker: Inês Gomes Campos

Congress: CPC 2024
Topic: D. Heart Failure
Theme: 10. Chronic Heart Failure
Subtheme: 10.6 Chronic Heart Failure - Clinical
Session Type: Sessão de Casos Clínicos
FP Number: ---
Authors: Inês Gomes Campos; Isabel Cruz; Bruno Bragança; Rafaela G. Lopes; Mauro Moreira; Adriana Pereira; Inês Gonçalves; Aurora Andrade

<p style="text-align:justify"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000"><strong><span style="font-family:Arial,sans-serif">Introduction</span></strong></span></span></span></p>

<p style="text-align:justify"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000"><span style="font-family:Arial,sans-serif">Desmoplakin (DSP) cardiomyopathy is a recently described form of arrhythmogenic cardiomyopathy, characterized by episodes of acute myocardial injury, left ventricular involvement with extensive fibrosis and high arrhythmic risk.</span></span></span></span></p>

<p style="text-align:start"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000"><strong><span style="font-family:Arial,sans-serif">Case report</span></strong></span></span></span></p>

<p style="text-align:justify"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000"><span style="font-family:Arial,sans-serif">In January 2020, a 19-year-old woman is admitted in the emergency department due to rest chest pain exacerbated when breathing deeply, with a 4-hour duration. Serial electrocardiogram showed sinus rhythm with no dynamic ST segment alterations. High sensitivity troponin was 4282pg/mL with negative inflammatory parameters. Transthoracic echocardiography revealed preserved biventricular systolic function with normal segmental contractility and no pericardial effusion. Coronary angiogram excluded coronary artery anomalies and disease. A probable acute myocarditis was assumed. She evolved favorably with no heart failure signs and no dysrhythmic events. Ambulatory cardiac magnetic resonance imaging (cMRI) later revealed inflammation and fibrosis in the subepicardial lateral wall. </span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000"><span style="font-family:Arial,sans-serif">In July and December 2020, January 2021 and March, August and October 2022, she had recurrent episodes of acute myocardial injury. Etiological study was relevant for positive antinuclear and smooth-muscle antibodies, thus leading to immunosuppressive therapy initiation in the suspicion of an auto-immune etiology. cMRI revealed extensive subepicardial left ventricular (LV) late gadolinium enhancement (LGE) in a ring-like pattern. Endomyocardial biopsy showed a first segment of adipose tissue and a second with interstitial fibrosis, with no evidence of inflammation. Cardiotropic viruses assay was negative.</span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000"><span style="font-family:Arial,sans-serif">Given the repetitive episodes of myocardial injury and the extensive pattern of fibrosis, genetic test for arrhythmogenic LV cardiomyopathy was requested, later revealing an heterozygotic variant of unknown significance in the DSP gene.</span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000"><span style="font-family:Arial,sans-serif">She is currently under outpatient follow-up with no recurrence of events in a 15-month period. </span></span></span></span></p>

<p style="text-align:start"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000"><strong><span style="font-family:Arial,sans-serif">Discussion</span></strong></span></span></span></p>

<p style="text-align:start"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000"><span style="font-family:Arial,sans-serif">In this case report, the occurrence of myocarditis-like episodes, combined with the extensive subepicardial LV LGE and the identified genetic variant in the DSP gene (despite being of unknown significance to date), makes the diagnosis of DSP cardiomyopathy extremely likely. First degree relatives will be genetically evaluated for segregation analysis. Having a high index of suspicion is of paramount importance, given the associated high risk of ventricular arrhythmias (reported to be ~30%). Dedicated tools to predict risk and guide cardioverter-defibrillator implantation remain an unmet need in the management of these patients. </span></span></span></span></p>