P2Y inhibitor loading dose before catheterization in ST-segment elevation myocardial infarction: Is this the best strategy?

Introduction And Objectives: In ST-segment elevation myocardial infarction (STEMI) the benefit of dual antiplatelet therapy is unequivocal, but the optimal time to administer the loading dose (LD) of a P2Y inhibitor is the subject of debate and disagreement. The main aim of this study was characterize current practice in Portugal and to assess the prognostic impact of P2Y inhibitor LD administration strategy, before versus during or after primary percutaneous coronary intervention (PCI).

Methods: This multicenter retrospective study based on the Portuguese National Registry on Acute Coronary Syndromes included patients with STEMI and PCI performed between October 1, 2010 and September 19, 2017. Two groups were established: LD before PCI (LD-PRE) and LD during or after PCI (LD-CATH).

Results: A total of 4123 patients were included, 66.3% in the LD-PRE group and 32.4% in the LD-CATH group. Prehospital use of a P2Y inhibitor was a predictor of the composite bleeding endpoint (major bleeding, need for transfusion or hemoglobin [Hb] drop >2g/dl), Hb drop >2g/dl and reinfarction. There were no differences between groups in major adverse events (MAE) (in-hospital mortality, reinfarction and stroke) or in-hospital mortality.

Conclusions: Prehospital use of a P2Y inhibitor was associated with an increased risk of bleeding, predicting the composite bleeding outcome and Hb drop >2g/dl, with no differences in mortality or MAE, calling into question the benefit of this strategy.