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

Not Applicable

Not yet recruiting

• Conditions: ACS - Acute Coronary Syndrome; Ticagrelor; Microbiota; Platelet Aggregation; Myocardial Infarction (MI); Blood Platelets; Drug Effects; Platelet Aggregation Inhibitors; Drug Resistance; Platelet Function Tests
• Interventions: Drug: Rifaximin

• Registration Number: NCT07203846
• Lead Sponsor: Collegium Medicum w Bydgoszczy

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.

Study Timeline

• Status Verified: 2025-09
• Study First Submitted: 2025-09-25
• Study First Submitted QC: 2025-09-25
• Last Update Submitted: 2025-09-25
• Study First Posted: 2025-10-02
• Last Update Posted: 2025-10-02
• Study Start: 2026-01-01
• Primary Completion: 2026-12-31
• Study Completion: 2027-06-30

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 50

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
High platelet reactivity patients receiving rifaximin	Rifaximin	Participants identified as having high platelet reactivity treated with oral rifaximine

Primary Outcome Measures

Name	Time	Method
Change in platelet reactivity in Multiplate	0-7 days	Relative reduction in platelet reactivity from baseline to post-intervention by \>10%, assessed with Multiplate analyzer (multiple electrode aggregometry)
Achievement of platelet reactivity below HPR	0-7 days	Achieving platelet reactivity below HPR in a patient with a higher baseline value, assessed with Multiplate analyzer (multiple electrode aggregometry)

Secondary Outcome Measures

Name	Time	Method
Relative reduction in platelet reactivity	0-7 days	Relative reduction in platelet reactivity from baseline to post-intervention by \>10%, assessed with VerifyNow P2Y12 assay
Achieving platelet reactivity below HPR in VerifyNow	0-7 days	Achieving platelet reactivity below HPR in a patient with a higher baseline value, assessed with VerifyNow P2Y12 assay
Relative reduction in platelet reactivity in thromboelastography	0-7 days	Relative reduction in platelet reactivity from baseline to post-intervention by \>10%, assessed with Platelet Mapping assay (thromboelastography)
Achieving platelet reactivity below HPR in thromboelastography	0-7 days	Achieving platelet reactivity below HPR in a patient with a higher baseline value, assessed with Platelet Mapping assay (thrombelastography)
Changes in microbiome profile	0-7 days	Changes in microbiome profile post-intervention assessed using 16S rRNA sequencing

Trial Locations

Locations (1)

Cardiology Department, Dr. A. Jurasz University Hospital; 🇵🇱 Bydgoszcz, Cuiavian-Pomeranian, Poland