Author(s): Francone M, Chimenti C, Galea N, Scopelliti F, Verardo R,
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Abstract OBJECTIVES: The aim of this study was to determine whether clinical presentation and type of cell death in acute myocarditis might contribute to cardiac magnetic resonance (CMR) sensitivity. BACKGROUND: Growing evidence indicates CMR is the reference noninvasive tool for the diagnosis of acute myocarditis. However, factors affecting CMR sensitivity are still unclear. METHODS: We retrospectively evaluated 57 consecutive patients with a diagnosis of acute myocarditis made on the basis of clinical history (≤3 months) and endomyocardial biopsy evidence of lymphocytic infiltrates (≥14 infiltrating leukocytes/mm(2) at immunohistochemistry) in association with damage of the adjacent myocytes and absence or minimal evidence of myocardial fibrosis. CMR acquisition protocol included T2-weighted (edema), early (hyperemia), and late (fibrosis/necrosis) gadolinium enhancement sequences. Presence of ≥2 CMR criteria denoted myocarditis. Type of cell death was evaluated by using in situ ligation with hairpin probes. RESULTS: Three clinical myocarditis patterns were recognized: infarct-like (pattern 1, n = 21), cardiomyopathic (pattern 2, n = 21), and arrhythmic (pattern 3, n = 15). Tissue edema was observed in 81\% of pattern 1, 28\% of pattern 2, and 27\% of pattern 3. Early enhancement was evident in 71\% of pattern 1, 67\% of pattern 2, and 40\% of pattern 3. Late gadolinium enhancement was documented in 71\% of pattern 1, 57\% of pattern 2, and 47\% of pattern 3. CMR sensitivity was significantly higher in pattern 1 (80\%) compared with pattern 2 (57\%) and pattern 3 (40\%) (p < 0.05). Cell necrosis was the prevalent mechanism of death in pattern 1 compared with pattern 2 (p < 0.001) and pattern 3 (p < 0.05), whereas apoptosis prevailed in pattern 2 (p < 0.001 vs. pattern 1 and p < 0.05 vs. pattern 3). CONCLUSIONS: In acute myocarditis, CMR sensitivity is high for infarct-like, low for cardiomyopathic, and very low for arrhythmic clinical presentation; it correlates with the extent of cell necrosis-promoting expansion of interstitial space. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
This article was published in JACC Cardiovasc Imaging
and referenced in Journal of Clinical Case Reports