Post-COVID-19 Vaccination Myocarditis: A Histopathologic Study on a Monocentric Series of Six Cases

Hyo-Suk Ahn; Yuran Ahn; Jaehyuk Jang; Seonghyun Bu; Sungmin Lim; Chanjoon Kim; Jong-Min Lee; Kyungji Lee; Kyung-Jin Seo

doi:10.3390/diagnostics14020219

Post-COVID-19 Vaccination Myocarditis: A Histopathologic Study on a Monocentric Series of Six Cases

Diagnostics (Basel). 2024 Jan 19;14(2):219. doi: 10.3390/diagnostics14020219.

Authors

Hyo-Suk Ahn^{1

2}, Yuran Ahn^{1

2}, Jaehyuk Jang^{1

2}, Seonghyun Bu^{1

2}, Sungmin Lim^{1

2}, Chanjoon Kim^{1

2}, Jong-Min Lee^{1

2}, Kyungji Lee³, Kyung-Jin Seo⁴

Affiliations

¹ Division of Cardiology, Department of Internal Medicine, Uijeongbu St. Mary's Hospital, The Catholic University of Korea, Seoul 06591, Republic of Korea.
² Catholic Research Institute for Intractable Cardiovascular Disease (CRID), College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea.
³ Midwest International Research Institute, Midwest University, 851 Parr Rd., Wentzville, MO 63385, USA.
⁴ Department of Hospital Pathology, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea.

Abstract

Many reports on the development of myocarditis following coronavirus disease 2019 (COVID-19) vaccination (PCVM) have emerged. However, only a few case studies have investigated endomyocardial biopsy (EMB) results. This study describes the clinicopathologic features of PCVM. We surveyed all hospitalized patients in a single university hospital in Korea and identified six cases of PCVM. All six patients underwent EMB, five of whom were men aged 15-85 years. All patients developed cardiac dysfunction. Among these patients, two had mild disease without sequelae, whereas the other four had dilated cardiomyopathy with depressed cardiac function. All six cases demonstrated lymphohistiocytic myocarditis. Two of our cases fulfilled the criterion of CD3+ T lymphocytes > 7 cells/mm² (Case nos. 3 and 6), while the remaining four cases did not fulfill the Dallas criteria. In conclusion, most PCVM cases showed mild degree inflammation histopathologically, and some cases could not fulfill the Dallas criteria and were classified as borderline myocarditis.

Keywords: COVID-19 vaccination; endomyocardial biopsy; myocarditis.

Grants and funding

This research was partly supported by the Catholic University of Korea, Uijeongbu St. Mary’s Hospital Clinical Research Laboratory Foundation, in the program year 2023 (5-2023-B0001-00253); Korean Heart Failure Registry III funded by the Korean Society of Heart Failure; and the Material Parts Technology Development Program funded by the Ministry of Trade, Industry & Energy (MOTIE), Korea (No. 20023097).