Factors Affecting Platelet Reactivity 2 Hours After P2Y₁₂ Receptor Antagonist Loading in Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction　– Impact of Pain-to-Loading Time –

摘要

Background: Delay in the onset of antiplatelet action occurs in patients with ST-elevation myocardial infarction (STEMI) and is likely due to disturbed absorption. We hypothesized that patients presenting relatively late after the onset of symptoms would have faster antiplatelet action. Methods?and?Results: We analyzed patient-level data from 5 studies of 207 P2Y₁₂receptor antagonist-na?ve patients with STEMI undergoing primary percutaneous coronary intervention (PCI). All patients had available platelet reactivity (PR) assessment with the VerifyNow assay (in P2Y₁₂reaction units; PRU) prior to and 2 h after loading. High PR (HPR) was defined as ≥208 PRU. Pain-to-antiplatelet loading time independently predicted PR at 2 h after loading: every 1-h increase in pain-to-antiplatelet loading time produced a 7% decrease in PR (P=0.001). Pretreatment PR, body mass index, morphine and novel P2Y₁₂receptor antagonist also affected PR 2 h after loading. Novel P2Y₁₂receptor antagonist use and per hour increase in pain-to-antiplatelet loading time were independently associated with lower probability for HPR with an OR (95% CI) of 0.145 (0.095–0.220) and 0.776 (0.689–0.873), P12receptor antagonist loading, according to patient-level data pooled analysis. ( Circ J 2016; 80: 442–449)