Author + information
- Margaret Infelda,b,
- Kevin Friedea,b,
- Rachel A. Myersa,b,
- Thomas Ortela,b,
- Tan Ru Sana,b and
- Deepak Vooraa,b
Background: Non-white patients are under-represented in antiplatelet clinical trials. The goal of this study was to examine differences in platelet function responses to aspirin (ASA) and ticagrelor by race, which have not been extensively studied to date.
Methods: Platelet function data (n=1,868 observations) were gathered from four prior studies conducted in White (W, n=282), African American (AfAm, n=109), and Asian (n=84) participants. Ex-vivo platelet function was measured by area under the light transmission aggregometry curve (AUC) stimulated with epinephrine 10 uM, collagen 5mg/ml, and adenosine diphosphate (ADP) 5 uM at baseline (n=696), after ASA (n=887), and after ticagrelor (n=285). Linear mixed effect regression models estimated race effect and race-treatment interactions after adjusting for comorbidities, age, and gender within each study and then combined using inverse-variance weighted random-effect meta-analysis.
Results: The average age was 47 years, 46% were male (n=275), 28% had diabetes (n=171), 21% had hyperlipidemia (n=127), 23% had hypertension (n=140), and 8% had coronary disease (n= 48). ASA and ticagrelor resulted in significant suppression of platelet function (change in AUC: −348 units with ASA, −197 units with ticagrelor for epi; −47 units with ASA and −326 units with ticagrelor for ADP; −103 units with ASA and −26 units with ticagrelor for collagen). Holding treatment constant and compared to W, AfAm subjects had lower platelet function with epinephrine (-70 unit AUC, p=.0003) and ADP (-22 unit AUC, p=.002). The treatment effect of ASA varied by race. Compared to W, AfAm patients had higher platelet function on ASA (+33 unit AUC, p=.05) with epinephrine and Asian patients had lower platelet function with collagen (-55 unit AUC, p = 0.002) on ASA. The treatment effect of ticagrelor varied by race. Compared to W, AfAm patients had lower platelet function with ADP (-22 unit AUC, p=0.02) and with collagen (-27 unit AUC, p=0.02) on ticagrelor.
Conclusions: AfAm patients demonstrate lower levels of platelet function at baseline and experience a larger decrease in response to ASA and ticagrelor. Asian patients had enhanced suppression of platelet function in response to ASA.
Poster Hall, Hall C
Sunday, March 19, 2017, 9:45 a.m.-10:30 a.m.
Session Title: Antiplatelet and Antithrombotic Agents in Ischemic Heart Disease
Abstract Category: 3. Acute and Stable Ischemic Heart Disease: Therapy
Presentation Number: 1296-309
- 2017 American College of Cardiology Foundation