The utility of delayed-enhancement magnetic resonance imaging for identifying nonischemic myocardial fibrosis in asymptomatic patients with biopsy-proven systemic sarcoidosis.

BACKGROUND The pathophysiology of sarcoidosis includes infiltrative inflammatory injury, as well as interstitial fibrosis formation. Delayed-enhancement (DE) magnetic resonance imaging (MRI) techniques have been shown to identify fibrotic tissue as areas of hyperenhancement. To test the hypothesis that DE-MRI can be used to identify myocardial fibrosis resulting from cardiac sarcoidosis, we assessed this method in asymptomatic patients with biopsy-proven systemic sarcoidosis. METHODS Thirty-one patients with biopsy-confirmed systemic sarcoidosis and no known history of heart disease or sarcoid cardiac involvement underwent DE-MRI after gadolinium-chelate administration. The location and extent of DE were quantified by 2 radiologists experienced at evaluating cardiovascular MRI images. RESULTS According to DE-MRI, 8 (26%) of the 31 patients had nonischemic fibrosis, as evidenced by abnormal DE patterns. Unlike characteristic ischemic injuries, most of the fibrosis was mid-myocardial, extending to the adjacent endocardium, epicardium, or both. The most frequent site of fibrosis was the basal inferoseptum, followed by the basal inferolateral wall. CONCLUSIONS In asymptomatic patients with systemic sarcoidosis, DE-MRI may provide a novel, noninvasive method for the early identification of myocardial fibrosis.