Brief report: Antisynthetase syndrome-associated myocarditis

Background The antisynthetase (AS) syndrome is characterized by autoimmune myopathy, interstitial lung disease, cutaneous involvement, arthritis, fever, and antibody specificity. We describe 2 patients with AS syndrome who also developed myocarditis, depressed biventricular function, and congestive heart failure.

Methods and Results Both patients were diagnosed with AS syndrome based on clinical manifestations, detection of serum AS antibodies, and myositis confirmation with the use of skeletal muscle magnetic resonance imaging and skeletal muscle biopsy. In addition, myocarditis resulting in heart failure was confirmed with the use of cardiac magnetic resonance imaging and from endomyocardial biopsy findings. After treatment for presumed AS syndrome-associated myocarditis, one patient recovered and the other patient died.

Conclusions AS syndrome is a rare entity with morbidity and mortality typically attributed to myositis and lung involvement. This is the first report of AS syndrome-associated myocarditis leading to congestive heart failure in 2 patients. Given the potentially fatal consequences, myocarditis should be considered in patients with AS syndrome presenting with heart failure.