Aims
To characterize and follow patients with ST-segment elevation myocardial infarction (STEMI) at high bleeding risk (HBR) according to the predicting bleeding complications in patients undergoing stent implantation and subsequent dual antiplatelet therapy (PRECISE-DAPT) score, and to examine the use of P2Y12 inhibitors and the subsequent risk of major adverse cardiovascular events (MACE) and bleeding.

Methods and results
This single-centre cohort study included 6179 consecutive STEMI patients who underwent percutaneous coronary intervention (PCI) at Copenhagen University Hospital, Rigshospitalet, between 2009 and 2016. Individual linkage to nationwide registries was conducted to obtain information on diagnoses, claimed drugs, and vital status. Of the 5532 (89.5%) patients with available PRECISE-DAPT scores, 33.0% were at HBR and more often elderly and female with more comorbidities than non-HBR patients. One-year cumulative incidence rates per 100 person-years were 8.7 and 2.1 for major bleeding and 36.8 and 8.3 for MACE in HBR and non-HBR patients, respectively. Among the 4749 (85.8%) patients who survived and collected a P2Y12 inhibitor ≤7 days from discharge, 68.2% of HBR patients were treated with ticagrelor or prasugrel and 31.8% with clopidogrel, while 18.2% non-HBR patients were treated with clopidogrel. Adherence was high for all (>75% days coverage). The risk of MACE was lower in ticagrelor- and prasugrel-treated patients than in clopidogrel-treated patients without differences in major bleeding.

Conclusion
One-third of PCI-treated all-comer patients with STEMI were at HBR according to the PRECISE-DAPT score and were more often treated with potent P2Y12 inhibitors instead of clopidogrel. Thus, ischaemic risk may be weighted over bleeding risk in STEMI patients at HBR.