Lupus myocarditis: a single center experience and a comparative analysis of observational cohort studies.

Background Lupus myocarditis (LM) is reported in 3-9% of patients with systemic lupus erythematosus (SLE) but limited evidence exists regarding optimal treatment and prognosis. This study aims to describe LM in a defined lupus cohort as compared with the existing literature. Patients and methods Patients with LM were identified from the University of Toronto Lupus Clinic database. Diagnosis was based on clinical manifestations and electrocardiographic, imaging, and biochemical criteria. Demographic, clinical, diagnostic and therapeutic variables and outcomes were collected in a standardized data retrieval form. A literature review was performed to identify cohort studies reporting on LM treatment and outcome. A comparative analysis was conducted between our patients and the combined cohort of the existing studies. Results Thirty patients were diagnosed with LM (prevalence 1.6%) and compared with a cumulative cohort of 117 patients from five distinct studies. No significant differences were found regarding the age at diagnosis (32.6 ± 13.4 years) and SLE duration (2.5 years median). Concomitant lupus activity from other organ systems was observed in 97% of the patients. Chest pain was more frequently reported in our cohort whereas dyspnea was more prominent in the other studies. Diagnostic criteria were similar across studies. Therapeutic approach was comparable and consisted of glucocorticosteroids (96.6%) and immunosuppressives (70%). Mortality was approximately 20% whereas another 20% of the patients achieved partial and 60% complete recovery. Conclusions LM usually occurs early in the disease course and in the context of generalized lupus activity. Despite aggressive therapy, approximately 40% of the patients died or had residual heart damage.