Effect of Two Weeks of Low-Dose Apixaban on Platelet Reactivity in Patients With Stable Coronary Artery Disease on Dual Antiplatelet Therapy (Aspirin and Clopidogrel)

NCT07853612 | Active Not Recruiting Phase 4

• 1 other identifier: CEC1151/06/19
• Study Type: interventional
• Target: 16
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to learn whether a low dose of apixaban, a blood-thinning medicine, changes how active the platelets are in adults with stable coronary artery disease who are already taking aspirin and clopidogrel. Platelets are small blood cells that help form clots. Aspirin and clopidogrel are used to keep platelets from clumping and to lower the risk of heart attack and stroke. In some people, however, platelets stay very active even while taking these medicines, which raises the risk of future heart problems. Apixaban works on a different part of the clotting process, and researchers want to find out whether it lowers platelet activity further. The main questions it aims to answer are: Does taking low-dose apixaban for 14 days lower platelet activity, as measured by the VerifyNow P2Y12 test (reported as P2Y12 reaction units, or PRU)? Does low-dose apixaban change how platelets respond to aspirin, as measured by the VerifyNow aspirin test (reported as aspirin reaction units, or ARU)? Is 14 days of low-dose apixaban, added to aspirin and clopidogrel, safe and well tolerated? There is no separate comparison group. Researchers will compare each participant's platelet test results before starting apixaban with that same participant's results after 14 days of apixaban. Participants will: Have a screening interview and a review of their medical history and current medicines Give a small blood sample (about 5 mL) for platelet function testing before starting apixaban Take apixaban 2.5 mg by mouth twice a day for 14 days, while continuing their usual aspirin and clopidogrel Return on Day 14 to give a second blood sample for platelet function testing and safety blood tests Receive a phone call from a study doctor at Day 30 to check for side effects or other health problems Participants will receive a copy of their platelet test results. This is a small pilot study of about 16 participants at one site in Trinidad and Tobago.

Conditions

Coronary Artery Disease; High On-treatment Platelet Reactivity (HTPR)

Keywords

apixaban; Factor Xa Inhibitors; Platelet Function Tests; Dual Antiplatelet Therapy; Aspirin; Clopidogrel; Clopidogrel Resistance

Outcome Measures

Primary Outcomes (1)

• Change in P2Y12 Reaction Units (PRU) From Baseline to Day 14

  Platelet reactivity measured with the VerifyNow P2Y12 assay in whole blood, reported in P2Y12 reaction units (PRU). The change is calculated as the Day 14 value minus the baseline value for each participant. Lower values indicate greater platelet inhibition.

  Baseline (before the first dose of apixaban) and Day 14

Secondary Outcomes (2)

• Change in Aspirin Reaction Units (ARU) From Baseline to Day 14

  Baseline and Day 14

• Number of Participants With Bleeding Events

  From the first dose of apixaban through Day 30

Study Arms (1)

Low-Dose Apixaban Added to Aspirin and Clopidogrel

EXPERIMENTAL

Adults with stable coronary artery disease who have been taking aspirin and clopidogrel for at least 6 months have baseline platelet function testing. They then take apixaban 2.5 mg by mouth twice daily for 14 days while continuing their usual aspirin and clopidogrel. Platelet function testing and safety blood tests are repeated on Day 14, and a study physician conducts a follow-up telephone call at Day 30 to assess adverse events.

Drug: Apixaban

Interventions

Apixaban DRUG

Apixaban is an oral direct factor Xa inhibitor approved by the U.S. FDA. Participants take a total of 28 doses (2.5 mg every 12 hours), with the first dose given after the baseline blood sample is collected. Participants who have not started apixaban are not given a loading dose, and there is no washout period before or after treatment. Apixaban is stopped after the Day 14 blood sample, and participants continue their usual antiplatelet therapy as prescribed by their own physician.

Also known as: Eliquis, Apiban, Apo-apixaban

Low-Dose Apixaban Added to Aspirin and Clopidogrel

Eligibility Criteria

• Age: 18 Years - 74 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• between 18 and 74 years of age,
• have stable coronary artery disease, already on DAPT with aspirin and clopidogrel for at least 6 months,
• not on any physician-prescribed medications or complementary/alternative therapies.

You may not qualify if:

• presence of active internal bleeding or history of bleeding diathesis or clinical findings associated with an increased risk of bleeding,
• history of ischemic or hemorrhagic stroke, transient ischemic attack, intracranial neoplasm, arteriovenous malformation, or aneurysm,
• history of clinical and/or hemodynamic instability,
• within 1 month of placement of a bare metal stent,
• within 30 days of coronary artery bypass graft surgery,
• planned coronary revascularization,
• treatment with fibrin-specific fibrinolytic therapy \<24 h or non-fibrin-specific fibrinolytic therapy \<48 h,
• use of an oral anticoagulation agent or an international normalized ratio \>1.5,
• body weight \<60 kg,
• age \>75 years,
• hemoglobin \<10 g/dL,
• platelet count \<100000/μL,
• creatinine \>2 mg/dL,
• hepatic enzymes \>2.5 times the upper limit of normal,
• pregnancy and/or lactation,

Sponsors & Collaborators

• The University of The West Indies: lead

Study Sites (1)

Trinidad Institute of Medical Technology

Saint Augustine, Trinidad and Tobago

Location

Related Publications (7)

• Coughlin SR. Protease-activated receptors in hemostasis, thrombosis and vascular biology. J Thromb Haemost. 2005 Aug;3(8):1800-14. doi: 10.1111/j.1538-7836.2005.01377.x.

  PMID: 16102047 BACKGROUND

• Tantry US, Bonello L, Aradi D, Price MJ, Jeong YH, Angiolillo DJ, Stone GW, Curzen N, Geisler T, Ten Berg J, Kirtane A, Siller-Matula J, Mahla E, Becker RC, Bhatt DL, Waksman R, Rao SV, Alexopoulos D, Marcucci R, Reny JL, Trenk D, Sibbing D, Gurbel PA; Working Group on On-Treatment Platelet Reactivity. Consensus and update on the definition of on-treatment platelet reactivity to adenosine diphosphate associated with ischemia and bleeding. J Am Coll Cardiol. 2013 Dec 17;62(24):2261-73. doi: 10.1016/j.jacc.2013.07.101. Epub 2013 Sep 27.

  PMID: 24076493 BACKGROUND

• Torramade-Moix S, Palomo M, Vera M, Jerez D, Moreno-Castano AB, Zafar MU, Rovira J, Diekmann F, Garcia-Pagan JC, Escolar G, Cases A, Diaz-Ricart M. Apixaban Downregulates Endothelial Inflammatory and Prothrombotic Phenotype in an In Vitro Model of Endothelial Dysfunction in Uremia. Cardiovasc Drugs Ther. 2021 Jun;35(3):521-532. doi: 10.1007/s10557-020-07010-z.

  PMID: 32651897 BACKGROUND

• Pujadas-Mestres L, Lopez-Vilchez I, Arellano-Rodrigo E, Reverter JC, Lopez-Farre A, Diaz-Ricart M, Badimon JJ, Escolar G. Differential inhibitory action of apixaban on platelet and fibrin components of forming thrombi: Studies with circulating blood and in a platelet-based model of thrombin generation. PLoS One. 2017 Feb 13;12(2):e0171486. doi: 10.1371/journal.pone.0171486. eCollection 2017.

  PMID: 28192448 BACKGROUND

• Lopes RD, Heizer G, Aronson R, Vora AN, Massaro T, Mehran R, Goodman SG, Windecker S, Darius H, Li J, Averkov O, Bahit MC, Berwanger O, Budaj A, Hijazi Z, Parkhomenko A, Sinnaeve P, Storey RF, Thiele H, Vinereanu D, Granger CB, Alexander JH; AUGUSTUS Investigators. Antithrombotic Therapy after Acute Coronary Syndrome or PCI in Atrial Fibrillation. N Engl J Med. 2019 Apr 18;380(16):1509-1524. doi: 10.1056/NEJMoa1817083. Epub 2019 Mar 17.

  PMID: 30883055 BACKGROUND

• Granger CB, Alexander JH, McMurray JJ, Lopes RD, Hylek EM, Hanna M, Al-Khalidi HR, Ansell J, Atar D, Avezum A, Bahit MC, Diaz R, Easton JD, Ezekowitz JA, Flaker G, Garcia D, Geraldes M, Gersh BJ, Golitsyn S, Goto S, Hermosillo AG, Hohnloser SH, Horowitz J, Mohan P, Jansky P, Lewis BS, Lopez-Sendon JL, Pais P, Parkhomenko A, Verheugt FW, Zhu J, Wallentin L; ARISTOTLE Committees and Investigators. Apixaban versus warfarin in patients with atrial fibrillation. N Engl J Med. 2011 Sep 15;365(11):981-92. doi: 10.1056/NEJMoa1107039. Epub 2011 Aug 27.

  PMID: 21870978 BACKGROUND

• Seecheran NA, Maharaj A, Boodhai B, Seecheran R, Seecheran V, Persad S, Ramsaroop K, Sandy S, Giddings S, Sakhamuri S, Ali R, Motilal S, Teelucksingh S, Tello-Montoliu A. Prevalence of clOpidogrel 'resIstaNce' in a selected population of patients undergoing elective percutaneous coronary intervention at a tertiary cardiovascular centre in Trinidad: the POINT pilot study. Open Heart. 2019 Feb 27;6(1):e000841. doi: 10.1136/openhrt-2018-000841. eCollection 2019.

  PMID: 30997117 RESULT

MeSH Terms

Conditions

Coronary Artery Disease

Interventions

apixaban

Condition Hierarchy (Ancestors)

Coronary Disease; Myocardial Ischemia; Heart Diseases; Cardiovascular Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Vascular Diseases

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Senior Lecturer, Interventional Cardiology Consultant, Department of Clinical Medical Sciences

Model Details: Prospective, single-arm, open-label, before-and-after pilot study in which each participant serves as their own control. Participants continue their usual aspirin and clopidogrel and take apixaban 2.5 mg twice daily for 14 days. Platelet function is measured with the VerifyNow P2Y12 and Aspirin assays at baseline and again on Day 14. There is no washout period and no separate comparison group.

Study Record Dates

• First Submitted: September 26, 2026
• First Posted: October 2, 2026
• Study Start: September 3, 2026
• Primary Completion (Estimated): October 1, 2027
• Study Completion (Estimated): October 1, 2028
• Last Updated: October 2, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will not share

Locations

TR (1)