Background and introduction Prasugrel is an ideal antiplatelet agent for use in patients presenting with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI) because of its rapid onset of antiplatelet action. However, trials have suggested an increased bleeding risk with Prasugrel compared to Clopidogrel because of its increased relative potency leading to a recommendation that it should not be used in patients with high bleeding risk (HBR) - >75yrs of age, <60kg in weight or a prior history of cerebrovascular accident (CVA).

Purpose There are some theoretical advantages in using Prasugrel for loading in all patients undergoing PPCI and switching to Clopidogrel (or low dose Prasugrel) for maintenance. Our STEMI protocol suggests Prasugrel loading for all comers undergoing PPCI on this basis (irrespective of bleeding risk). We examined the bleeding incidence and mortality in STEMI patients who underwent PPCI and received Prasugrel loading despite having HBR characteristics and compared it to those who received Clopidogrel (because of HBR) and those who did not have HBR characteristics (who received Prasugrel loading).

Methods 295 patients who underwent PPCI from 1/9/2017 - 4/6/2018 at Nottingham University Hospitals had their records reviewed retrospectively. The patients were assigned to one of 3 groups: 1) Clopidogrel Loading (generally because of HBR), 2) Prasugrel Loading-HBR and 3) Prasugrel Loading non-HBR. The Bleeding Academic Research Consortium (BARC) score was used to evaluate the bleeding episodes during admission and out to 6 weeks at clinic review. Mortality data were also collected.

Results 35 patients received Clopidogrel (group 1). The incidence of any BARC bleeding was 8.6% and in-hospital mortality was 20%. 54 patients with HBR received Prasugrel (group 2). The incidence of any BARC bleeding was 16.7% (p=0.27 by chi squared compared to group 1) and in-hospital mortality was 7.4% (p=0.078 by chi squared compared to group 1). 206 patients without HBR characteristics received Prasugrel loading (group 3). The incidence of any BARC bleeding was 6.3%. In-hospital mortality was 5.3%. (Table 1).

Conclusions HBR patients with Prasugrel loading before undergoing PPCI have a numerical increase in the risk of bleeding as compared to those receiving Clopidogrel loading, but this was not statistically significant. Furthermore, most of the bleeding was relatively minor (BARC1-22.2%, BARC2-55.6%, BARC3a-22.2%). However, there was a numerically lower in-hospital mortality for patients with HBR loaded with Prasugrel compared to Clopidogrel (although not quite reaching statistical significance). There are limitations with this retrospective analysis and prospective randomised trials looking at Prasugrel loading for patients with HBR undergoing PPCI would be useful. Potentially, STEMI protocols could be significantly simplified if Prasugrel loading for all-comers was deemed to be safe and efficacious.

Conflict of Interest None