Baseline predictors of on-treatment platelet activity (as P-selectin expression) in patients in the triple aniplatelets for reducing dependency in ischaemic stroke (TARDIS) trial

Bath, Philip M.; Woodhouse, Lisa J.; Dovlatova, Natalia; May, Jane; Heptinstall, Stan

Abstract

Background: Platelet activity may be measured remotely as surface P-selectin expression. Predictors of on-treatment P-selectin expression were assessed using baseline characteristics in the TARDIS trial.
Methods: TARDIS assessed intensive (combined aspirin, dipyridamole and clopidogrel, ACD) versus guideline (aspirin/dipyridamole, AD; or clopidogrel alone, C) antiplatelets in 3096 patients with acute stroke or TIA. On-treatment P-selectin levels were measured remotely at 7 days post randomisation. The tests detected the effects of either aspirin or clopidogrel. Analyses have been split by test and randomised treatment.
Results: 626 patients (ACD 312, AD 142, C 172) had P-selectin taken at day 7. For the aspirin sensitive test, P-selectin expression was only related to prior antiplatelet treatment in ACD patients: those on A (mean difference, MD -69.6, p=0.010) or AC (MD -95.3, p=0.037) prior to randomisation had lower levels than those on nothing. None of the baseline characteristics had any relationship with P-selectin in AD patients. For the clopidogrel test, P-selectin levels were only related to prior antiplatelet therapy in ACD patients: patients on C had lower levels (MD -157.5, p=0.026), and those on AD had higher levels (MD 210.1, p=0.0044) than those on nothing. In C patients, P-selectin was lower in smokers than non-smokers (MD -128.4, p=0.0048) and patients with a history of hypertension had higher levels (MD 83.1, p=0.036).
Conclusion: In ACD patients, prior antiplatelet treatment appeared to effect ontreatment P-selectin. In clopidogrel alone patients, P-selectin expression was lower in smokers than non-smokers, suggesting that smokers are less likely to exhibit resistance to clopidogrel.

Citation

Bath, P. M., Woodhouse, L. J., Dovlatova, N., May, J., & Heptinstall, S. (2018). Baseline predictors of on-treatment platelet activity (as P-selectin expression) in patients in the triple aniplatelets for reducing dependency in ischaemic stroke (TARDIS) trial.

• Conference Name: 11th World Stroke Congress 2018
• Start Date: Oct 17, 2018
• End Date: Oct 20, 2018
• Acceptance Date: May 27, 2018
• Publication Date: Oct 17, 2018
• Deposit Date: Aug 17, 2018
• Publicly Available Date: Jan 18, 2019
• Public URL: https://nottingham-repository.worktribe.com/output/1036854
• Additional Information: Abstract 048 published in International Journal of Stroke, v. 13, issue 2 supplement, October 2018.
• Contract Date: Aug 17, 2018