Effect and Safety of Fexofenadine Hydrochloride vs Placebo in Patients With Acute Myocardial Infaction: A Randomized Clinical Trial

Inclusion Criteria: * Ages above 18; * Being able to verbally confirm understanding of the trial risks, benefits, and treatment options of receiving treatment with fexofenadine hydrochloride. He/she or his/her legal representative shall provide written informed consent before participating in the clinical trial. * Meet the diagnostic criteria for STEMI, the diagnostic criteria includes: 1. Clinical symptoms: ischemic chest pain lasting for over 30 minites; 2. Elevated serum cTn: at least once higher than the upper limit of normal values (99th percentile of the reference upper limit); 3. ST segment elevation: new ST segment elevation in two or more adjacent leads on the ECG; * Emergency coronary angiography and revascularization should be performed; * Ultrasonic cardiogram indicates regional wall motion abnormality, and transthoracic echocardiography shows LVEF ≤ 50% within 72 hours after revascularization. Exclusion Criteria: * Long term use of fexofenadine hydrochloride or other H1 receptor inhibitors; * Previously suffered from myocardial infarction or received coronary artery bypass grafting; * Patients with concomitant cardiomyopathy or valve disease; * History of severe renal failure, estimated glomerular filtration rate (eGFR) \< 30ml/min; * History of severe liver dysfunction; * Concurrent severe infections, or liver/gallbladder obstruction, or history of malignant tumors; * Currently receiving immunosuppressive therapy; * Pregnant or potentially pregnant and breastfeeding women; * Contraindications for fexofenadine hydrochloride or cardiac magnetic resonance examinations; * Without obtaining written informed consent. * Patients with hemodynamic instability.