title: CMR sensitivity varies with clinical presentation and extent of cell necrosis in biopsy-proven acute myocarditis.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Radiology, Oncology and Pathology, La Sapienza University, Rome, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Francone
authors.affiliation: Department of Cardiovascular, Respiratory, Nefrologic, Anestesiologic and Geriatric Sciences, La Sapienza University, Rome, Italy; IRCCS San Raffaele La Pisana, Rome, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Chimenti
authors.affiliation: Department of Radiology, Oncology and Pathology, La Sapienza University, Rome, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Galea
authors.affiliation: IRCCS L. Spallanzani, Rome, Italy.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Scopelliti
authors.affiliation: IRCCS L. Spallanzani, Rome, Italy.
authors.forename: Romina
authors.initials: R
authors.lastname: Verardo
authors.affiliation: Fondazione IRCSS Ospedale Maggiore Policlinico Università degli Studi di Milano, Rome, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Galea
authors.affiliation: Department of Radiology, Oncology and Pathology, La Sapienza University, Rome, Italy.
authors.forename: Iacopo
authors.initials: I
authors.lastname: Carbone
authors.affiliation: Department of Radiology, Oncology and Pathology, La Sapienza University, Rome, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Catalano
authors.affiliation: Department of Cardiovascular, Respiratory, Nefrologic, Anestesiologic and Geriatric Sciences, La Sapienza University, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Fedele
authors.affiliation: Department of Cardiovascular, Respiratory, Nefrologic, Anestesiologic and Geriatric Sciences, La Sapienza University, Rome, Italy; IRCCS L. Spallanzani, Rome, Italy. Electronic address: biocard@inmi.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Frustaci
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D017209:Apoptosis; D001706:Biopsy; D003287:Contrast Media; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009205:Myocarditis / Q000473:pathology*; D009206:Myocardium / Q000473:pathology*; D009336:Necrosis; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index
chemical_list: D003287:Contrast Media
keywords: acute myocarditis; apoptosis; cardiac magnetic resonance; necrosis; viruses