WILLOW-ACS - Version 1
Research type
Research Study
Full title
A study of very low dose twice-daily compared to standard low dose once-daily aspirin following acute coronary syndromes - WILL lOWer dose aspirin be more effective following ACS?
IRAS ID
191516
Contact name
Robert Storey
Contact email
Sponsor organisation
Sheff REC - Sheffield Teaching Hospitals NHS Foundation Trust
Eudract number
2016-000920-25
Duration of Study in the UK
1 years, 0 months, 0 days
Research summary
Patients who develop acute coronary syndromes (ACS), including severe (‘unstable’) angina and myocardial infarction (heart attack), are currently treated with a combination of 2 antiplatelet drugs (dual antiplatelet therapy, DAPT), aspirin and ticagrelor. Aspirin works by inhibiting the release of thromboxane, a substance which promotes thrombosis, but at higher doses is also able to reduce the release of prostacyclin, a substance which prevents thrombosis. Aspirin reduces thromboxane even at very low doses, including those lower than the current standard. Lower doses of aspirin have also been associated with less bleeding.
A large randomised controlled trial, the PLATO study, showed that aspirin and ticagrelor are better than the previous standard combination of aspirin and clopidogrel. The results also suggested that patients on lower doses of aspirin gained more benefit from ticagrelor than those on high doses. This may be because ticagrelor has effects on limiting the damage caused by a heart attack and that, in animal studies, these effects are reduced by high dose but not low dose aspirin. Whilst ticagrelor is a stronger antiplatelet drug than aspirin, their effects are additive and so both drugs may be important. Another consideration is that once daily dosing of aspirin, the current standard, has been shown to be insufficient in a significant number of patients.
This study is comparing a very low dose of aspirin twice daily with the current standard low dose once daily in patients on DAPT for ACS. Patients with a history of recent ACS who meet the study inclusion/exclusion criteria will be invited to participate. Patients will be randomised to one of the two aspirin doses for 14 days, then have blood and urine tests before being asked to take the other dose for the next 14 days followed by further blood and urine tests.REC name
Yorkshire & The Humber - Sheffield Research Ethics Committee
REC reference
16/YH/0119
Date of REC Opinion
15 Apr 2016
REC opinion
Favourable Opinion