Jong-Chan Youn1, Hyo Sup Shim2, Jae Seok Lee3, Ah-Young Ji1, Jaewon Oh1, Namki Hong1, Hye Sun Lee4, Sungha Park1, Sang-Hak Lee1, Donghoon Choi1, Namsik Chung1, Seok-Min Kang5. 1. Division of Cardiology, Severance Cardiovascular Hospital and Cardiovascular Research Institute, Yonsei University College of Medicine, Seoul, Korea. 2. Department of Pathology, Yonsei University College of Medicine, Seoul, Korea. Electronic address: shimhs@yuhs.ac. 3. Department of Pathology, Yonsei University College of Medicine, Seoul, Korea. 4. Department of Biostatistics, Yonsei University College of Medicine, Seoul, Korea. 5. Division of Cardiology, Severance Cardiovascular Hospital and Cardiovascular Research Institute, Yonsei University College of Medicine, Seoul, Korea; Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea. Electronic address: smkang@yuhs.ac.
Abstract
BACKGROUND: The long-term prognosis of biopsy-proven myocarditis is not well known. We hypothesized that a detailed pathological examination of an endomyocardial biopsy (EMB) would reveal prognostic information in patients with acute myocarditis. METHODS: Fifty-four patients were diagnosed with acute myocarditis based on an EMB. Pathological diagnosis was categorized into lymphocytic dominant (29.6%), eosinophilic dominant (22.2%), and borderline myocarditis (48.1%). Masson's trichrome staining and further immunohistochemical staining for CD3, CD20, CD68, HLA-DR, TLR4, TLR8, enteroviral VP1, and caspase-3 expression were performed. The clinical outcomes were defined as all-cause and cardiovascular (CV) death. RESULTS: During the median 10.4 years of follow up (9.7±5.7 years), the overall all-cause mortality was 20.4% and the CV mortality was 14.8% in patients with acute myocarditis. Lymphocytic dominant myocarditis patients showed a poor clinical outcome when compared with eosinophilic dominant myocarditis patients for both all-cause (37.5% vs. 0%, p=0.015) and CV (31.2% vs. 0%, p=0.029) mortality. Among borderline myocarditis patients, the presence of fibrosis was linked with poor clinical outcomes in both all-cause (75.0% vs. 21.4%, p=0.045) and CV (100.0% vs. 25.0%, p=0.034) mortality. No significant associations between clinical outcome and all other immunohistochemical staining targets were observed. CONCLUSIONS: Detailed pathological evaluation on an EMB provides prognostic information in patients with acute myocarditis. EMB evaluation should be considered in patients with suspected myocarditis.
BACKGROUND: The long-term prognosis of biopsy-proven myocarditis is not well known. We hypothesized that a detailed pathological examination of an endomyocardial biopsy (EMB) would reveal prognostic information in patients with acute myocarditis. METHODS: Fifty-four patients were diagnosed with acute myocarditis based on an EMB. Pathological diagnosis was categorized into lymphocytic dominant (29.6%), eosinophilic dominant (22.2%), and borderline myocarditis (48.1%). Masson's trichrome staining and further immunohistochemical staining for CD3, CD20, CD68, HLA-DR, TLR4, TLR8, enteroviral VP1, and caspase-3 expression were performed. The clinical outcomes were defined as all-cause and cardiovascular (CV) death. RESULTS: During the median 10.4 years of follow up (9.7±5.7 years), the overall all-cause mortality was 20.4% and the CV mortality was 14.8% in patients with acute myocarditis. Lymphocytic dominant myocarditispatients showed a poor clinical outcome when compared with eosinophilic dominant myocarditispatients for both all-cause (37.5% vs. 0%, p=0.015) and CV (31.2% vs. 0%, p=0.029) mortality. Among borderline myocarditispatients, the presence of fibrosis was linked with poor clinical outcomes in both all-cause (75.0% vs. 21.4%, p=0.045) and CV (100.0% vs. 25.0%, p=0.034) mortality. No significant associations between clinical outcome and all other immunohistochemical staining targets were observed. CONCLUSIONS: Detailed pathological evaluation on an EMB provides prognostic information in patients with acute myocarditis. EMB evaluation should be considered in patients with suspected myocarditis.