Manka, Robert

Abstract Background and Aims Acute myocarditis (AM) is a T cell-mediated myocardial disease with clinical manifestations ranging from mild chest pain to cardiogenic shock. Reliable biomarkers to stratify patients and guide therapy are currently lacking. In particular, the extent of the dysregulation of inflammatory pathways, and the impact on myocardial dysfunction, remain elusive. Methods Serum analyses were performed in prospectively recruited AM patients (n = 103) from two independent cohorts. Multimodal data integration combining profiling of cytokine and chemokine dysregulation with clinical biomarkers was used to define clinical phenotypes with distinct inflammatory signatures. Machine-learning and regression models were applied to determine biomarkers that indicate clinical severity. Results Immuno-proteomic profiling revealed conserved inflammatory patterns across AM cohorts, dominated by T cell-related cytokines and chemokines. In addition, AM patients showed dysregulation of fibroblast-derived cytokines, including hepatocyte growth factor (HGF), bone morphogenic protein 4 (BMP4) and the BMP4 inhibitors Gremlin-1 (GREM1) and Gremlin-2 (GREM2). Data integration and unsupervised clustering revealed two immuno-clinical phenotypes, linking T cell activation and fibroblast dysregulation to disease severity. Machine learning-based analysis identified CXCL10, GREM2 and LVEF as critical parameters for stratifying disease severity. Conclusions These findings highlight a systemic T cell activation signature as diagnostic hallmark of AM. In addition, dysregulation of fibroblast-derived tissue cytokines serves as an indicator for distinct immuno-clinical phenotypes in myocardial inflammatory disease. Thus, the clinically relevant link between T cell-driven immune activation, myocardial inflammation and fibroblast-driven remodelling provides a versatile set of parameters to identify severe manifestations of AM. Graphical Abstract Key Question: Are serological immune signatures linked to clinical severity in acute myocarditis and do they enable patient stratification? Key Findings: T cell- and fibroblast associated proteomic signatures indicate disease severity in acute myocarditis. Novel immuno-clinical phenotypes stratify patients according to distinct immune responses and clinical manifestations. CXCL10, GREM2 and LVEF are the most important parameters to identify immuno-clinical phenotypes. Take Home Message: CXCL10, GREM2 and LVEF emerge as key determinants for a severe immuno-clinical phenotype in acute myocarditis, highlighting the role of T cell-fibroblast interaction in the disease process and linking T cell activation, fibroblastic tissue remodelling and impaired cardiac function.

Abstract Background Sports activities may promote arrhythmias in the setting of acute myocarditis. International cardiovascular society recommendations to return to sports activities following acute myocarditis are based on expert consensus in the absence of prospective studies. Purpose We sought to identify patients who may safely resume sports activities 3 months after acute myocarditis. Methods We prospectively enrolled 27 patients with newly diagnosed myocarditis based on clinical parameters, elevated high sensitive troponin (TnT-hs) and cardiac magnetic resonance imaging (CMR) with mildly reduced or preserved LVEF. Follow-up examination included laboratory findings, electrocardiogram (ECG), 48-hour-Holter ECG, echocardiography, exercise stress testing and CMR. Cessation of physical activity was recommended for 3 months. All patients were followed for cardiac events for 12 months. Results Average age was 35 (19–80) years with 73% male patients. All patients performed 3- and 6-month follow-up with above mentioned diagnostic tests. Eight patients did not present for 12-month follow-up, but were contacted by phone. No cardiac events occurred within the interval of 12 months. After 3 months, participants achieved an average of 92% of predicted maximum power on stress test. One case of non-sustained ventricular tachycardia was recorded during 48-hour-Holter ECG. Except for this case, all patients were allowed to resume physical exercise after 3 months. At 6- (n=26) and 12-month (n=19) follow-up no arrhythmias, recurrent myocarditis, worsening left ventricular ejection fraction (LVEF) or physical performance were recorded. TnT-hs, creatine kinase (CK), myoglobin (Mb), and C-reactive protein (CRP) normalized. Conclusion The risk of cardiac events and decreasing LVEF appears to be low after early resumption of exercise in asymptomatic patients who recover from acute myocarditis. Acknowledgement/Funding Forschungskredit of the University of Zurich,the Holcim Foundation, the Hartmann Müller Foundation, and the Walter and Gertrud Siegenthaler Foundation