Colchicine Versus Placebo in Acute Myocarditis Patients

Inclusion Criteria:

• Symptom onset of 21 days or less,

• Chest pain and/or Heart failure symptoms and/or palpitations

• Troponins superior to 99 percentile of reference value,

• Myocarditis diagnostic confirmation (by Contrast-Enhanced Cardiac Magnetic Resonance (CMR), according to the Lake Louise criteria (2009 or later),

• No evidence for ischemic heart disease on coronary angiography or coronary computedtomography angiography for patients with age superior to 40-year-old with one ormore cardiovascular risk factor (hypertension, smoking, hypercholesterolemia,diabetes, personal or family history of coronary artery disease),

• Woman of child-bearing age with an effective contraception method according to theinvestigator for the duration of treatment and one month after,

• Man accepting effective contraception for the duration of treatment and one monthafter,

• Participant with affiliation to the French Health Care System "sécurité sociale",

• Written informed consent of the patient obtained.

Exclusion Criteria:

• Cardiogenic shock requiring inotropes or vasopressors (patients with inotropesdiscontinued for more than 24 hours can be enrolled)

• Giant cell myocarditis or eosinophilic myocarditis

• Acute coronary syndrome or known coronary stenosis superior to 50%

• Toxic cardiomyopathy

• Active chronic inflammatory disease, chronic active infection, evolving cancer

• A recent severe sepsis (7 days)

• Hypersensitivity to Investgational Medical Product's active substances (colchicine)or to any of the excipients (including lactose, sucrose, microcrystalline cellulose,colloidal silica, magnesium stearate, colourants : E127, Dual Red 40 )

• Any known contra-indication to CMR or associated contract products (claustrophobia;intra-ocular metal foreign bodies, clips such as cerebral, carotid, or aorticaneurysm, cochlear implants, any implant held in by magnet, non-MR compatiblecardiac devices (pace maker or defibrillator); history of hypersensitivity togadoteric acid or to gadolinium contrast agents or to meglumine),

• Chronic treatment with corticosteroids or Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) or immunosuppressant.

• Sarcoidosis

• Severe liver (Child Pugh C) or known renal dysfunction (known Glomerular FiltrationRate (GFR) less or equal to 30 ml/min according Cockroft),

• Cytopenia : hemoglobin less than 100 grams/L, white blood cell count less than 3.0G/L, platelet count less than 100 G/L

• Major digestive disorders (chronic diarrhea, inflammatory disease of the digestivetract as uncontrolled ulcerative colitis or active Crohn disease)

• Immunosuppression, spinal cord aplasia

• Hemopathy

• Hypereosinophilia more than 0.5 G/L

• Pregnant or nursing women, where pregnancy is defined as the state of a female afterconception and until the termination of gestation, confirmed by a positive locallaboratory test,

• Administration of any investigational drug or participation in anotherinterventional trial, within 30 days before randomization,

• Participant under treatment having an interaction with colchicine [macrolides (telithromycin, azithromycin, clarithromycin, dirithromycin, erythromycin,josamycin, midecamycin, roxithromycin), pristinamycin,, cyclosporine, verapamil, allprotease inhibitors, telaprevir, CYP3A4 powerful inhibitors, azole antifungals,vitamin K antagonists]

• Participant under legal protection: under guardianship (trusteeship or curatorship)