Antiplatelet Therapy

Bleeding Time

I (Geo) received this question on May 23, 2025: “I am using 100 mg of aspirin and 75 mg of Plavix. My PTT is 35.8 seconds; PT 13.8 seconds, INR 1.18; bleeding time is 1 minute and 30 seconds; clotting time is 8 minutes. Are these results normal when using the two drugs together?” I […]

Antiplatelet Therapy

A Molecular Approach to Assess Platelet Hyperreactivity

Friend Ed Groenendal forwarded this UPI summary of a molecular approach correlating evidence of hyperresponsive platelets to major adverse cardiac or limb events. The investigators started with aggregometry-defined platelet hyperreactivity to apply a transcriptome-based platelet reactivity expression score (PRESS). Click below to see the detailed open-access article describing the development and application of the PRESS. […]

Antiplatelet Therapy

Mixing Studies and Various Therapeutics

From Leslie Chaparro: We recently had a patient who had a mixing study ordered but who had recently taken tranexamic acid [TXA]. We exclude patients that have been on anticoagulants but have never really considered drugs that encourage clotting. How would this affect the patient’s mixing study? How do we keep up with all the […]

Anticoagulant Therapy

February, 2022 Quick Question: Platelet Aggs

Our February 2022 Quick Question asks, What single agonist is your first choice to measure platelet response to aspirin? The typical aggregation profile includes several agonists, however it may be that one is more sensitive to aspirin’s antiplatelet effect than the others. As always, please add your comments below.

Antiplatelet Therapy

Primary CVD Disease: Is Low Dose ASA Effective?

Thanks to Dean Willett, Precision BioLogic Inc, for pointing me to this October 12, 2021 US Preventive Services Task Force release, “Aspirin Use to Prevent Cardiovascular Disease: Preventive Medication,” which recommends against daily low-dose aspirin as a means to reduce the risk of cardiovascular disease, ischemic stroke, and colorectal cancer regardless of age or comorbities. […]

Antiplatelet Therapy

VWD and Aspirin

An acquaintance’s daughter has type 1 von Willebrand disease. Her OB physician recommends a daily baby aspirin during her pregancy. Are there any circumstances in which aspirin is indicated during pregnancy in a woman with VWD? Please provide your opinion in our Comments section below or email to [email protected]. Thank you.

Antiplatelet Therapy

AUGUSTUS Trial: Apixaban and Clopidogrel

Click or tap here to learn the results of the AUGUSTUS trial, which shows that the combination of apixaban and a P2Y12 inhibitor such as clopidogrel is safer than Coumadin and clopidogrel, Coumadin and aspirin, or apixaban and aspirin for post-PCI or acute coronary syndrome therapy.

Anticoagulant Therapy

TWILIGHT Study: Discontinue Aspirin

Click or tap here to read and hear about the TWILIGHT trial outcomes that illustrate how three months after cardiac catheterization (PCI), aspirin may be discontinued. The trial showed that ticagrelor monotherapy was equally effective and safer than tacagrelor plus aspirin.

Antiplatelet Therapy

Aspirin Presentation October 16, 2019

Click here for George’s Northeast Laboratory Conference presentation handout, “Aspirin, the 1899 Wonder Drug Lives Again,” presented October 16, 2019 in Portland, Maine.

Antiplatelet Therapy

Zontivity (vorapaxar)

I’m curious about how many of our participants monitor vorapaxar (Zontivity®, New American Therapeutics, Inc) antiplatelet therapy. Vorapaxar is the only protease-activated receptor-1 (PAR-1) antagonist that reduces thrombotic cardiovascular events in patients with a history of myocardial infarction or peripheral arterial disease, FDA-approved in 2014. Vorapaxar is used alongside dual antiplatelet therapy (aspirin and clopidogrel; aspirin and ticagrelor) […]

Antiplatelet Therapy

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George Fritsma is a medical laboratory scientist, educator, and author. George holds faculty appointments with Rutgers University and Michigan State University, and is a member of the International Society on Thrombosis and Hemostasis, American Association of Clinical Chemists, and American Society for Clinical Laboratory Science.

Cheat Sheets from George

Quick Question