One-year Prognostic Impact of Microcirculation Assessed by NH IMR Angio in Patients Hospitalized for Acute Myocarditis

Inclusion criteria

• Male or female patients over the age of 18.
• Patients hospitalized between June 2015 and July 2025.
• Patients who presented with chest pain and at least 1 diagnostic criterion; or, in the absence of chest pain, at least 2 of the following diagnostic criteria:

• Electrocardiographic abnormalities (ST-segment elevation or depression, T-wave inversions, conduction disturbances such as type 3 atrioventricular block),
• Elevated troponin levels,
• Abnormal kinematics on echocardiography.
• Associated with MRI findings of ≥2 tissue abnormalities (edema, hyperemia, myocardial fibrosis).
• Coronary angiography performed during the initial hospitalization
• Patient enrolled in or eligible for a social security program.
• Patient who has expressed consent to participate.

Exclusion criteria

• Absence of coronary artery disease confirmed by coronary angiography
• Myocarditis secondary to immunotherapy
• Presence of documented coronary artery disease (coronary angiography or cardiac CT)
• Presence of cardiomyopathy (hypertrophic cardiomyopathy, dilated cardiomyopathy)
• Infiltrative heart disease (sarcoidosis or cardiac amyloidosis)
• Severe valvular heart disease
• Takotsubo syndrome
• Constrictive or chronic pericarditis
• Loeffler's endocarditis
• Left ventricular noncompaction
• Cardiac tumor
• Pulmonary embolism
• Coronary spasm
• Patients covered by Articles L1121-5 through L1121-8 of the Public Health Code (pregnant women, women in labor, and breastfeeding women; persons deprived of their liberty by judicial or administrative decision; adults under guardianship)