Author + information
- Kevin Friede,
- Margaret Infeld,
- Ru-San Tan,
- Rachel Myers and
- Deepak Voora
Background: Aspirin's benefits for prevention of coronary artery disease differs by sex. While aspirin equally suppresses its target COX-1 in both sexes, platelets in women treated with aspirin retain greater platelet reactivity to COX-1-independent agonists in whole blood. Whether these differences are due to an inherent platelet difference and whether they extend to ticagrelor are unknown.
Methods: Platelet rich plasma (PRP) samples were collected from 4 groups of subjects (n = 598) from both sexes and multiple ethnic groups at the Duke Clinical Research Unit (Durham, NC, USA), and the SingHealth Investigational Medicine Unit (Singapore). Samples were collected at baseline (n = 696) and after 2 or 4 weeks of daily aspirin (n = 887) or ticagrelor (n = 315) administration. Light transmittance aggregometry was used to measure ex-vivo platelet function in response to epinephrine, collagen, and adenosine diphosphate (ADP). A random-effects model was used to determine whether baseline platelet function or in response to drug varied by sex while controlling for age, race, cardiovascular risk factors, and study cohort. An inverse variance weighted meta-analysis framework was used to combine effects across studies.
Results: Platelet function decreased significantly in subjects treated with both aspirin and ticagrelor. Aspirin-treated female subjects had lower platelet reactivity in response to epinephrine at 1 μM (p = 0.044) but not at 10 or 0.05 μM. A trend for higher platelet reactivity in response to ADP was seen at 10 μM (p = 0.081) but not 5 or 1 μM. No significant relationships were seen in samples exposed to collagen.
Conclusions: In this analysis of platelet function measured in PRP, we observed minimal differences between sex and COX-1-independent platelet responses. This differs from previous studies showing clear differences in whole blood platelet assays. Further study is required to elucidate whether interactions with non-platelet blood cells are responsible for sex differences, and whether these can account for differences in outcomes seen in large clinical trials of anti-platelet agents for prevention of cardiovascular disease.
Moderated Poster Contributions
Acute and Stable Ischemic Heart Disease Moderated Poster Theater, Poster Hall, Hall C
Saturday, March 18, 2017, 1:00 p.m.-1:10 p.m.
Session Title: Anti-Platelet Therapies: Always a Sticky Topic
Abstract Category: 3. Acute and Stable Ischemic Heart Disease: Therapy
Presentation Number: 1227M-07
- 2017 American College of Cardiology Foundation