The goal of this observational study is to evaluate the association between post-coronary angiography IMR and medium-term clinical prognosis in patients with acute myocarditis. The main question it aims to answer is:

Is there a correlation between impaired microcirculation and the occurrence of serious clinical events in this population of patients?

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)

patients hospitalized in the cardiology department at CHUGA between 2015 and 2025 who had a diagnosis of myocarditis confirmed by cardiac MRI.