Table_1_Immunological response and temporal associations in myocarditis after COVID-19 vaccination using cardiac magnetic resonance imaging: An amplified T-cell response at the heart of it?.DOCX

IntroductionAlthough myocarditis after anti-SARS-CoV-2 vaccination is increasingly recognized, we have little data regarding the course of the disease and, consequently, the imaging findings, including the tissue-specific features. The purpose of this study is to describe the clinical, immunological, and cardiac magnetic resonance (CMR) features of myocarditis after COVID-19 immunization in the acute phase and during follow-up. We aimed to compare the trajectory of the disease to myocarditis cases unrelated to COVID-19.
MethodsWe assembled a CMR-based registry of potentially COVID-19 vaccination-related myocarditis cases. All patients who experienced new-onset chest pain and troponin elevation after COVID-19 vaccination and imaging confirming the clinical suspicion of acute myocarditis were enrolled in our study. Participants underwent routine laboratory testing and testing of their humoral and cellular immune response to COVID-19 vaccination. Clinical and CMR follow-up was performed after 3–6 months. We included two separate, sex- and age-matched control groups: (1) individuals with myocarditis unrelated to COVID-19 infection or vaccination confirmed by CMR and (2) volunteers with similar immunological exposure to SARS-CoV-2 compared to our group of interest (no difference in the number of doses, types and the time since anti-SARS-CoV-2 vaccination and no difference in anti-nucleocapsid levels).
ResultsWe report 16 CMR-confirmed cases of myocarditis presenting (mean ± SD) 4 ± 2 days after administration of the anti-SARS-CoV-2 vaccine (male patients, 22 ± 7 years), frequently with predisposing factors such as immune-mediated disease and previous myocarditis. We found that 75% received mRNA vaccines, and 25% received vector vaccines. During follow-up, CMR metrics depicting myocardial injury, including oedema and necrosis, decreased or completely disappeared. There was no difference regarding the CMR metrics between myocarditis after immunization and myocarditis unrelated to COVID-19. We found an increased T-cell response among myocarditis patients compared to matched controls (p < 0.01), while there was no difference in the humoral immune response.
ConclusionIn our cohort, myocarditis occurred after both mRNA and vector anti-SARS-CoV-2 vaccination, frequently in individuals with predisposing factors. Upon follow-up, the myocardial injury had healed. Notably, an amplified cellular immune response was found in acute myocarditis cases occurring 4 days after COVID-19 vaccination.

引言：尽管抗SARS-CoV-2疫苗接种后心肌炎的检出率日益升高，但目前关于该病的病程及相应影像学表现（包括组织特异性特征）的相关数据仍十分匮乏。本研究旨在描述新冠疫苗接种后心肌炎患者在急性期及随访过程中的临床、免疫学及心脏磁共振（cardiac magnetic resonance, CMR）特征，并将此类心肌炎的疾病进展轨迹与非新冠相关心肌炎病例进行对比。
方法：我们构建了一个基于CMR的新冠疫苗接种相关疑似心肌炎病例登记库。本研究纳入所有在新冠疫苗接种后出现新发胸痛、肌钙蛋白升高，且经影像学证实临床疑似急性心肌炎的患者。所有受试者均接受了常规实验室检测，以及针对新冠疫苗接种的体液免疫与细胞免疫应答检测。受试者在接种后3~6个月接受临床随访与CMR复查。本研究设置两个独立的性别与年龄匹配对照组：①经CMR证实为非新冠感染或疫苗接种相关的心肌炎患者；②与本研究目标队列免疫暴露情况相似的志愿者（两组在疫苗接种剂次、疫苗类型、接种后时长以及抗核衣壳抗体水平方面均无差异）。
结果：本研究共纳入16例经CMR证实的心肌炎病例，患者发病时间为接种抗SARS-CoV-2疫苗后4±2天（平均年龄22±7岁，均为男性），多数患者存在免疫介导性疾病、既往心肌炎等易感因素。其中75%的患者接种了mRNA疫苗，25%接种了病毒载体疫苗。随访期间，反映心肌损伤的CMR指标（包括水肿与坏死征象）均有所减轻或完全消失。疫苗相关心肌炎与非新冠相关心肌炎患者的CMR指标无显著差异。与匹配对照组相比，心肌炎患者的T细胞应答水平显著升高（p<0.01），而体液免疫应答无明显差异。
结论：在本研究队列中，mRNA疫苗与病毒载体疫苗接种后均可发生心肌炎，且此类病例多存在易感基础疾病。随访结果显示，心肌损伤可完全愈合。值得注意的是，在新冠疫苗接种后4天内发生的急性心肌炎患者中，可观察到显著增强的细胞免疫应答。