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)

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.

Timeline

Start

2026-09-03

Primary completion

2027-10-01

Completion

2028-10-01

Publications

• Background 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• Results 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.

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