POS0886 COULD BE INTERSTITIAL MYOCARDITIS A FEATURE OF THE ANTISYNTHETASE SYNDROME?
Authors: Gil-Vila A. , Burcet G. , Anton-Vicente A. , Gonzalez-Sans D. , Nuñez-Conde A. , Trallero-Araguás E. , Reyes-Juárez J. L. , Simeón-Aznar C. P. , Selva-O’callaghan A. 
Published: May 2021

Background:Antisynthetase syndrome (ASS) is characterized by inflammatory myopathy, interstitial lung disease, arthritis, mechanical hands and Raynaud phenomenon, among other features. Recent studies have shown that idiopathic inflammatory myopathies (IIM) may develop cardiac involvement, either ischemic (coronary artery disease) or inflammatory (myocarditis). We wonder if characteristic lung interstitial involvement (interstitial lung disease) that appears in patients with the ASS may also affect the myocardial interstitial tissue. New magnetic resonance mapping techniques could detect subclinical myocardial involvement, mainly as edema (increase extracellular volume in interstitium and extracellular matrix), even in the absence of visible late Gadolinium enhancement (LGE).Objectives:Our aim was to describe the presence of interstitial myocarditis in a group of patients with ASS.Methods:Cross-sectional, observational study performed in a tertiary care center. We included 13 patients diagnosed with ASS (7 male, 53%, mean (SD) age at diagnosis 56,8 years (±11,8)). The patients were consecutively selected from our outpatient myositis clinic. Myositis specific and associated antibodies were performed by means of line immunoblot (EUROIMMUN©). Cardiac magnetic resonance (CMR) was performed on all patients. The study protocol includes functional cine magnetic resonance and standard late gadolinium enhancement (LGE), as well as novel parametric T1 and T2 mapping sequences (modified look locker inversion recovery sequences - MOLLI) with extracellular volume (ECV) calculation 20 minutes after the injection of a gadolinium-based contrast material.Results:CMR could not be performed in one patient due to anxiety. All patients studied (12) had a normal biventricular function, without alteration of segmental contraction. A third (4 out of 12, 33%) of the studied patients showed elevated T2 myocardial values without focal LGE, half of them (2/4) with an elevated ECV, consistent with myocardial edema. Two patients with normal T2 values showed unspecific LGE focal patterns, one in the right ventricle union points and another with mild interventricular septum enhancement (Figure 1). None of the patients studied refer any cardiac symptomatology. All the four patients with T2 mapping alterations (100%) had interstitial lung involvement, but only 4 out of 8 (50%) of the rest ASS patients without T2 mapping positivity. The autoimmune profile was as follows: 10 anti-Jo1/Ro52, 1 anti-EJ/Ro52, 2 anti-PL12.Conclusion:Myocarditis, although subclinical, appears to be a feature in ASS patients. T1 and T2 mapping sequences might be valuable to detect and monitor subclinical cardiac involvement in these patients. The possibility that the same etiopathogenic mechanism may be involved in the interstitial tissue in lung and myocardium is raised. More studies must be done in order to assert the prevalence of myocarditis in ASS.References:[1]Dieval C et al. Myocarditis in Patients With Antisynthetase Syndrome: Prevalence, Presentation, and Outcomes. Medicine (Baltimore). 2015 Jul;94(26):e798.[2]Myhr KA, Pecini R. Management of Myocarditis in Myositis: Diagnosis and Treatment. Curr Rheumatol Rep. 2020 Jul 22; 22:49.[3]Sharma K, Orbai AM, Desai D, Cingolani OH, Halushka MK, Christopher-Stine L, Mammen AL, Wu KC, Zakaria S. Brief report: antisynthetase syndrome-associated myocarditis. J Card Fail. 2014 Dec;20(12):939-45.Figure 1.Cardiac magnetic resonance images from ASS patients.Disclosure of Interests:None declared