Study of variables in the stratification of risk in acute myocarditis: results from a tertiary hospital cohort

Abstract Introduction Acute myocarditis is a heterogeneous pathology that has various clinical presentations and can be classified in different risk levels. The purpose of this study is to evaluate parameters that can contribute to a better risk stratification in patients with acute myocarditis in order to recognise upon first aseessment those at higher risk of worse come up and facilitate clinical decision making. Methods Descriptive study of a historic cohort of 19 patients admitted un the Cardiac Intensive Care Unit of a tertiary hospital in Spain with the diagnosis of intermediate or high-risk myocarditis (according to the 2025 ESC Guidelines for the management of myocarditis and pericarditis) between January 2023 and March 2025. We carried out a comparison between groups of clinical, analytical and echocardiographic variables using the Fisher exact test, chi squared test, or Mann-Whitney u test according to the type of variable. Furthermore, we analysed the troponin kinetic (TnIUs) between groups. Results High-risk patients were more frequently female, without significant differences on age with the intermediate-risk group. Shock index on hospital admission was significantly higher in high-risk patients. Moreover, these patients had experienced syncope and heart failure symptoms more frequently. Blood test did not show significant differences in Albumin and NT-proBNP levels, though we found that C reactive protein and Procalcitonin levels were significantly higher in the high-risk group. Focusing on troponin levels, there were no differences on its peak value, but we did find differences on the TnIUS kinetic: in the high-group patients, the peak was significantly later (median 3 days 0,5-3,5 vs 0 days 0-1) (Figure 1). Regarding other complementary test, high-risk patients had higher incidence of microvoltages on the electrocardiogram (EKG), as well as left ventricle (LV) oedema and right ventricle (RV) dysfunction, both measured on cardiac ultrasound upon admission. Median LVEF in high-risk patients was 12,5% 10-17,5% and, although average time to LVEF normalisation tends to be longer in the high-risk group, it did not reach statistical significance, likely due to insufficient statistical power. The analysis of all variables of our study are shown in Table 1. Conclusion Shock index, microvoltages on EKG, LV oedema and RV dysfunction might be useful parameters when identifying patients with high-risk myocarditis. Also, troponin kinetic could be a useful parameter to evaluate myocarditis severity; however, more studies are necessary to confirm our findings.Figure 1 Table 1