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

NCT07203846 | Not Yet Recruiting Phase 4

• 1 other identifier: FLORA-ACS
• Study Type: interventional
• Target: 50
• Locations: 1 country
• Sites: 1

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.

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

Keywords

high platelet reactivity; HPR; Multiplate aggregometry; multiple electrode aggregometry; MEA; microbiome; gut flora; eubiotic; 16S rRNA sequencing; P2Y12 inhibitor

Outcome Measures

Primary Outcomes (2)

• Change in platelet reactivity in Multiplate

  Relative reduction in platelet reactivity from baseline to post-intervention by \>10%, assessed with Multiplate analyzer (multiple electrode aggregometry)

  0-7 days

• Achievement of platelet reactivity below HPR

  Achieving platelet reactivity below HPR in a patient with a higher baseline value, assessed with Multiplate analyzer (multiple electrode aggregometry)

  0-7 days

Secondary Outcomes (5)

• Relative reduction in platelet reactivity

  0-7 days

• Achieving platelet reactivity below HPR in VerifyNow

  0-7 days

• Relative reduction in platelet reactivity in thromboelastography

  0-7 days

• Achieving platelet reactivity below HPR in thromboelastography

  0-7 days

• Changes in microbiome profile

  0-7 days

Study Arms (1)

High platelet reactivity patients receiving rifaximin

EXPERIMENTAL

Participants identified as having high platelet reactivity treated with oral rifaximine

Drug: Rifaximin

Interventions

Rifaximin DRUG

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

Also known as: Xifaxan

High platelet reactivity patients receiving rifaximin

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Between 18 and 80 years of age
• 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

You may not qualify if:

• 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
• History of gastrointestinal diseases such as inflammatory bowel disease, bowel obstruction, or gastrointestinal tumor
• 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

Sponsors & Collaborators

• Collegium Medicum w Bydgoszczy: lead
• Ministry of Science and Higher Education, Poland: collaborator

Study Sites (1)

Cardiology Department, Dr. A. Jurasz University Hospital

Bydgoszcz, Cuiavian-Pomeranian, 85-094, Poland

Location

MeSH Terms

Conditions

Acute Coronary Syndrome; Myocardial Infarction; Dysbiosis

Interventions

Rifaximin

Condition Hierarchy (Ancestors)

Myocardial Ischemia; Heart Diseases; Cardiovascular Diseases; Vascular Diseases; Infarction; Ischemia; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Necrosis

Intervention Hierarchy (Ancestors)

Rifamycins; Heterocyclic Compounds, 4 or More Rings; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds; Lactams, Macrocyclic; Macrocyclic Compounds; Polycyclic Compounds

Study Officials

• Jacek Kubica, Prof.

  Collegium Medicum w Bydgoszczy

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Klaudyna Grzelakowska, MD

CONTACT

+48525854023; klaudyna.grzelakowska@gmail.com

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Prof.

Study Record Dates

• First Submitted: September 25, 2025
• First Posted: October 2, 2025
• Study Start: January 1, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): June 30, 2027
• Last Updated: October 2, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

PL (1)