fig1

Figure 1. Flowchart of patient selection and enrollment. Patients admitted with suspected fulminant myocarditis (FM) between January 2020 and January 2025 were screened at two tertiary centers (n = 404). Sequential exclusions were age < 18 years (n = 4), admission left ventricular ejection fraction (LVEF) > 50% (n = 18), pre-existing myocardial disease (n = 5), acute coronary syndrome (n = 31), sepsis-related myocardial injury (n = 14), and hypovolemic shock or unstable hemodynamics attributable to an alternative cause (n = 16). The final cohort comprised 316 adults, including 184 IVIG-treated and 132 non-IVIG-treated patients.