Objectives: The purpose of this study was to describe clinical phenotype and treatment outcomes in lupus myocarditis (LM), an uncommon but serious manifestation of systemic lupus erythematosus (SLE).
Methods: The study involved a 10-year retrospective case series of hospitalized patients with LM, with a search of a diagnosis database using systemic lupus erythematosus and either myocarditis, cardiomyopathy, or congestive heart failure, and of a pathology database for biopsy-proved LM.
Results: Twenty-four patients met the study criteria, with 79% female and 82% white (age: mean (SD), 47.6 (20.4) years; follow-up: mean (SD), 9.2 (6.1) months). The frequency of antibodies SS-A (69%) and anti-RNP (62%) was greater than in published lupus populations (25%-40%). On echocardiography, the mean initial left ventricular ejection fraction was 33.8%, improving to 49.5% after a mean of 7.2 months. All patients received immunosuppression, most with high-dose corticosteroid treatment and subsequent corticosteroid taper. One patient died of cardiogenic shock during hospitalization; two patients died within one year posthospitalization.
Conclusions: A high index of suspicion is necessary in suspected LM. Higher frequency of elevated SS-A and anti-RNP antibody levels in our series than in the literature is suggestive of an LM association. Echocardiography is a useful initial investigation for LM, but patients should be referred early for cardiac magnetic resonance imaging or endomyocardial biopsy to confirm diagnosis if it is clinically indicated in difficult cases.