The Many Faces of Cardiac Sarcoidosis

Introduction Cardiac involvement by sarcoidosis, a disease characterized by nonnecrotizing granulomas of unknown etiology, is rare and affects up to 7% of sarcoidosis patients clinically, but with an autopsy prevalence of 15% to 90%. The clinical presentation, as well as macroscopic and microscopic findings in cardiac sarcoidosis patients, varies. Methods Retrospective clinical chart review and gross and microscopic examination of surgical specimen from two adult cardiac sarcoidosis patients with literature review were performed. Results Case 1: A 23-year-old woman with no past medical history presented with 2 months of heart failure symptoms following a viral gastrointestinal infection. Endomyocardial biopsy showed a dense chronic inflammatory infiltrate, without giant cells. Anterior mediastinal lymph node biopsy and left apical core showed effacement by nonnecrotizing granulomas with giant cells and multifocal calcification, supporting cardiac sarcoidosis. Twelve months later, she underwent cardiac transplantation. The explanted heart showed concentric ventricular scarring, which microscopically corresponded to myocardial fibrosis with scattered lymphocytic inflammation with no residual granulomas. Case 2: A 52-year-old man with a medical history significant for ischemic cardiomyopathy and cutaneous sarcoidosis with lung involvement presented with congestive heart failure. Endomyocardial biopsy and left apical core showed myocyte hypertrophy and scattered interstitial inflammation. Mediastinal lymph node showed nonnecrotizing granulomas, consistent with sarcoidosis. Eighteen months later, he underwent cardiac transplantation. The explanted heart showed biventricular dilatation with interstitial fibrosis. There was also mild diffuse inflammation and occasional granulomas with rare focal necrosis. Conclusion Though the gold standard for diagnosing cardiac sarcoidosis is demonstration of myocardial nonnecrotizing granulomas, the sensitivity of endomyocardial biopsy is low. This is due to sampling error and stage of disease. Chronic end-stage disease can lead to fibrous encasement of granulomas and end-stage heart failure, necessitating cardiac transplantation. Current guidelines employ a combination of clinical, radiologic, and histologic criteria for diagnosing cardiac sarcoidosis.