Modulation of Gut MicroFLORA With Rifaximin to Reduce High Platelet Reactivity in Post-ACS Patients on Ticagrelor

Inclusion criteria: * Between 18 and 80 years of age * History of acute coronary syndrome no sooner than 1 month and no later than 12 months prior to study inclusion * Current treatment with ticagrelor (90 mg orally twice a day) * High platelet reactivity assessed with multiple electrode aggregometry method (AUC of \>46 U) * Provision of informed consent prior to any study procedures Exclusion criteria: * History of hypersensitivity to rifaximin or other rifamycin-derived agent * Ongoing treatment with rifamycins * Platelet count \< 100×10\^9/L or \> 450×10\^9/L * Treatment with antibiotics, probiotics, or glucocorticoids within 3 months prior to study inclusion * History of gastrointestinal diseases such as inflammatory bowel disease, bowel obstruction, or gastrointestinal tumor * Infection, including gastrointestinal infection, within a month prior to study inclusion * History of Clostridium difficile infection * Current use of specific medications (warfarin, glycoprotein IIb/IIIa inhibitors, immunosuppressants, bile acid sequestrants, antidiarrheal agents) * Impaired liver function classified as Child-Pugh class B or C * Hemodynamic instability * Pregnancy or breastfeeding * Patients considered by the investigator to be uncooperative