AB1159 Virus-negative lymphocytic myocarditis: clinical and diagnostic features from a monocentric italian cohort
Authors: S. Sartorelli, C. Campochiaro, G. De Luca, C. Candela, G. Cavalli, L. Dagna
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Virus-negative lymphocytic myocarditis (VNLM) is defined by endomyocardial biopsy (EMB) established histological, immunological and immune-histochemical criteria; it may occur as a distinct disease or in the context of systemic autoimmune or inflammatory disorders. <h3>Objectives</h3> To describe the demographic, clinical, histological and immune-histochemical features of VNLM from a monocentric Italian cohort. <h3>Methods</h3> 42 patients (mean age 45.57±14.9 years; male to female ratio 1:1) were diagnosed with EMB-proven VNLM at our Centre from January 2015 to December 2017. In all patients, comprehensive demographic, clinical and histological data were collected. <h3>Results</h3> The most common initial clinical feature was chest pain (40.5%), followed by palpitations (26.2%) and syncope (23.8%). Aborted sudden cardiac death (SCD) was the first manifestation in 3 cases, while arrhythmias were overall present in 47.6% of patients, being life-threatening in 10 of them. Interestingly, 4 patients had only few constitutional symptoms and 2 patients were completely asymptomatic. The distribution of traditional cardiovascular risk factor reflected that of the general population, apart for a more common familiarity for SCD (31.7%) and for autoimmunity (31.7%). Serum levels of troponin T and NT-proBNP were increased in 40.5% and 30.9%, respectively. Both echocardiography and standard ECG were unremarkable in half of the patients, while nearly all patients (92.5%) had at least one Lake-Louise criterion at cardiac magnetic resonance (CMR) evaluation. The most common CMR finding was delayed enhancement in 90% of cases, while T2-oedema was found in 21 patients (50%). Left ventricular ejection fraction was reduced in 50% of patients; a concomitant pericardial effusion was detected in 22.5% of cases. Abnormalities on 24h-ECG-Holter tape were overall detectable in 20 patients (47.6%), with ventricular ectopic beats and non-sustained ventricular tachycardia being the most common findings. Despite positivity for ANA in 42.8% patients, only 4 patients could be diagnosed with a systemic autoimmune disease. Anti-heart antibodies (AHA) and anti-intercalated disks antibodies (AIDA) were positive in 21 patients (50%) and 12 (28.6%) patients, respectively. On EMB, myocarditis was classified as active in 23 cases (54.8%) and as chronic in 18 (42.3%), while 7 patients (16.7%) had evidence of both features. CD3 +T-lymphocytes&gt;7/mm<sup>2</sup> were detectable in 27 patients (64.3%), necrosis in 20 patients (47.6%), oedema in 28 patients (66.7%), while only 4 patients showed signs of vasculitis or thrombotic microangiopathy. At time of diagnosis, myocardial fibrosis was evident in 73.8% of EMBs and dilated cardiomyopathy in 6 patients (14.3%). All patients were treated with steroids and azathioprine as first line therapy, and 17 patients (40.5%) were initially referred for device implantation. <h3>Conclusions</h3> VNLM is an overlooked disease characterised by a broad spectrum of clinical features and peculiar immune-mediated hallmarks. The early recognition of myocarditis, allowing a prompt therapeutic intervention, should be a major goal for rheumatologists. <h3>Disclosure of Interest</h3> S. Sartorelli: None declared, C. Campochiaro: None declared, G. De Luca: None declared, C. Candela: None declared, G. Cavalli: None declared, L. Dagna Grant/research support from: The Unit has received unrestricted educational grants from Abbvie, BMS, Celgene, Mundipharma, Novartis, MSD, Pfizer, Roche, and SOBI.