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

NCT ID: NCT07203846

Last Updated: 2025-10-02

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: PHASE4
• Total Enrollment: 50 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2026-01-01
• Study Completion Date: 2027-06-30

Brief Summary

The FLORA-ACS study aims to evaluate the relationship between dysbiosis and high platelet reactivity during treatment with ticagrelor in patients with a history of acute coronary syndromes and investigate the use of rifaximin to eliminate dysbiosis and thus provide effective antiplatelet treatment.

Detailed Description

A research hypothesis has been formulated indicating dysbiosis of the gut microbiota as a possible cause of high platelet reactivity (HPR) during treatment with an antiplatelet agent, ticagrelor, in post-acute coronary syndrome (ACS) patients. The use of rifaximin, an antibiotic exhibiting an eubiotic effect, may correct gut dysbiosis and help determine whether changes in the microbiota influence HPR.

The FLORA-ACS study will enroll 50 subjects with a history of ACS treated with ticagrelor (standard maintenance dose of 90 mg orally twice a day) and characterized by HPR. Participants will be enrolled in the study no sooner than 1 month and no later than 12 months following the ACS incident.

Platelet activity will be tested using the multiple electrode aggregometry method (Multiplate analyzer) with the HPR defined based on the consensus paper of the Working Group on On-Treatment Platelet Reactivity. Concurrently, fecal samples will be collected for microbiome profiling. The microbiota will be analyzed in terms of fecal bacterial richness and diversity using 16S ribosomal RNA sequencing.

Participants will receive a 7-day course of oral rifaximin (400 mg every 12 hours). Both platelet activity and microbiota testing will be conducted at baseline and post-treatment. Additional laboratory testing will include complete blood count and C-reactive protein. An analysis of major adverse cardiovascular events (MACE) occurrence within a 6-month follow-up period is planned.

Conditions

ACS - Acute Coronary Syndrome; Ticagrelor; Microbiota; Platelet Aggregation; Myocardial Infarction (MI); Blood Platelets; Drug Effects; Platelet Aggregation Inhibitors; Drug Resistance; Platelet Function Tests; Dysbiosis; Anti-Bacterial Agents; Rifaximin

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

High platelet reactivity patients receiving rifaximin

Participants identified as having high platelet reactivity treated with oral rifaximine

Group Type: EXPERIMENTAL

Rifaximin

Intervention Type: DRUG

Participants receiving a 7-day course of oral rifaximin 400 mg every 12 hours

Interventions

Rifaximin

Participants receiving a 7-day course of oral rifaximin 400 mg every 12 hours

Intervention Type: DRUG

Other Intervention Names

Xifaxan

Eligibility Criteria

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

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 80 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Ministry of Science and Higher Education, Poland

OTHER_GOV

Sponsor Role: collaborator

Collegium Medicum w Bydgoszczy

OTHER

Sponsor Role: lead

Responsible Party

Jacek Kubica

Prof.

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Jacek Kubica, Prof.

Role: PRINCIPAL_INVESTIGATOR

Collegium Medicum w Bydgoszczy

Locations

Cardiology Department, Dr. A. Jurasz University Hospital

Bydgoszcz, Cuiavian-Pomeranian, Poland

Countries

Poland

Central Contacts

Klaudyna Grzelakowska, MD

Role: CONTACT

klaudyna.grzelakowska@gmail.com

+48525854023

Other Identifiers

FLORA-ACS

Identifier Type: -

Identifier Source: org_study_id