Aspirin and ticagrelor are superior to aspirin and clopidogrel in preventing ischaemic complications in ACS but there is an increased rate of bleeding complications (Wallentin, Becker et al. 2009). There is some evidence that the benefit of ticagrelor over clopidogrel was diminished in patients taking higher doses of aspirin compared to lower doses (Mahaffey, Wojdyla et al. 2011).