Non-Steroidal Anti-Inflammatory Drugs in Acute Myocarditis

Inclusion Criteria: * Aged 18 years or older. * Patients hospitalized for confirmed acute myocarditis and left ventricular ejection fraction ventricular \>50%. * Elevated troponin I/T (3 times above the upper limit of normal). * Absence of acute heart failure. * Absence of ischemic heart disease (ruled out by coronary angiography or coronary CT in individuals over 40 years). * Diagnostic criteria for myocarditis (Lake Louise, 2018 update) by cardiac magnetic resonance imaging. Exclusion Criteria: * Kidney disease stage 3b, 4 and 5 (creatinine clearance by CKD-EPI \<45 ml/min/1.73 m2). * Severe liver failure (Child-Pugh class C). * Poorly controlled pharmacological hypertension (repeatedly systolic arterial pressure \>140 mmHg). * Diagnosis criteria for acute pericarditis. * Moderate or severe pericardial effusion (\>10 mm in total). * Hypersensitivity to NSAIDs or previous use in the last 7 days. * Contraindication for MRI. * Participation in another clinical trial. * Pregnancy, breastfeeding, or women of childbearing age unwilling to use appropriate contraception throughout the study. * Any circumstance that, in the investigator's opinion, compromises participation in the clinical trial.