No systematic reviews or randomised controlled trials studying the use of aspirin versus clopidogrel in patients with acute current chest pain could be identified in the literature. NICE base their guidance on a cohort study assessing the efficacy of aspirin when given pre or post hospital admission. A lower mortality rate was found in patients that received aspirin pre admission compared to post admission at 7 days, (2.4% versus 7.3%, P = 0.002) , and this remained significant at 30 day follow up. Pre hospital aspirin reduced the risks of asystole (P < 0.001), resuscitation (P < 0.001) and ventilation (P < 0.002).