Recurrent myocarditis-like episodes in a patient with a rare variant in DES gene: an uncommon hot-phases cardiomyopathy

Genetic alterations in DES gene, encoding for desmin—a muscle-specific intermediate filament (IF) protein—are associated with a broad phenotypic spectrum including cardiomyopathies, conduction abnormalities, and skeletal myopathy.1 An association between DES variants and myocardial inflammation has not been clearly established. Acute myocarditis and hot-phase cardiomyopathies can mimic acute coronary syndromes (ACSs),2,3 and in such scenarios, cardiac magnetic resonance (CMR) plays a crucial role in differential diagnosis, particularly in distinguishing ischaemic from non-ischaemic causes, such as Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA) and Takotsubo syndrome. Genetic testing is not mandatory in acute myocarditis but it may be warranted in selected cases.3 A 54-year-old Caucasian woman was referred to our centre after multiple episodes of MINOCA. Her medical history included subclinical hyperthyroidism, colonic diverticulosis, and a prior hysterectomy. She was a former smoker with no other cardiovascular risk factors. Her mother had a history of dilated cardiomyopathy (DCM), but there was no family history of sudden cardiac death (SCD) or malignant arrhythmias. The patient initially presented to a spoke centre in 2012 with acute-onset chest pain. Electrocardiogram (ECG) showed minimal repolarization abnormalities in leads DI and aVL. Troponin levels were elevated. Echocardiography revealed hypokinesis of the mid-basal anterior wall with preserved left ventricular ejection fraction (LVEF). Coronary angiography (CA) demonstrated normal coronary arteries, no invasive functional tests were performed. Cardiac magnetic resonance findings were consistent with myocardial inflammation in the basal and medial segments of the anterior and lateral walls (Figure 1). At the time, a presumptive diagnosis of MINOCA secondary to coronary vasospasm was made, and the patient was started on antiplatelet therapy, ranolazine, and a low dose of a statin and ACE inhibitor. She remained asymptomatic for the next 10 years, during this period she did not undergo follow-up CMR or cardiac enzyme monitoring. Cardiac magnetic resonance imaging during the acute phase of the first episode (2012). Basal short-axis and vertical long-axis T2-weighted sequences show signal hyperintensity in the basal and medial segments of the anterior and anterolateral walls (A). In the same segments LGE with a subepicardial and intramyocardial distribution is present, but it can be found also in the proximal and medial segments of the inferolateral and inferior walls. (B). These findings are consistent with myocardial oedema. 2018 Lake Louise Criteria for myocarditis are met. CMR, cardiac magnetic resonance; LGE, late gadolinium enhancement In April 2022, the patient re-presented with exertional chest pain. Electrocardiogram showed T-wave inversions in lateral leads (Figure 2). High-sensitivity troponin I (hs-TnI) measurements followed a curve peaking at 17 388 ng/l [normal values (n.v.)