P2Y12 receptor inhibition and effect of morphine in patients undergoing primary PCI for ST-segment elevation myocardial infarction

International audiencePRIVATE-ATLANTIC (P2Y12 Receptor Inhibition with VASP Testing using Elisa kit during the ATLANTIC study) is a pre-specified substudy of the randomised, double-blind ATLANTIC trial in patients with ST-segment elevation myocardial infarction, designed to help interpret the main trial results. The primary objective of ATLANTIC was to assess coronary reperfusion prior to percutaneous coronary intervention (PCI) with pre- vs in-hospital ticagrelor 180 mg loading dose (LD). PRIVATE-ATLANTIC assessed platelet inhibition in 37 patients by measurement of vasodilator-associated stimulated phosphoprotein (VASP) platelet reactivity index (PRI) and VerifyNow platelet reactivity units (PRU) before angiogram (T1), immediately after PCI (T2), 1 (T3), and 6 (T4) hours (h) after PCI, and before next study drug administration (T5). The median time difference between the two ticagrelor LD was 41 minutes. Platelet reactivity was unaffected at T1 when measured by VASP-PRI (89.8 vs 93.9 % for pre- and in-hospital ticagrelor, respectively; p = 0.18) or PRU (239 vs 241; p = 0.82). Numerical differences were apparent at T2 and maximal at T3. Morphine administration significantly delayed onset of platelet inhibition at T3 (VASP-PRI 78.2 vs 23.4 % without morphine; p = 0.0116) and T4 (33.1 vs 11.0 %; p = 0.0057). In conclusion, platelet inhibition in ATLANTIC was unaffected by pre-hospital ticagrelor administration at the time of initial angiogram due to the short transfer delay. The maximum difference in platelet inhibition was detected 1 h after PCI (T3). Morphine administration was associated with delayed onset of action of ticagrelor and appeared more important than timing of ticagrelor administration.TRIAL REGISTRATION:ClinicalTrials.gov NCT01347580

Effect of Pre-Hospital Ticagrelor During the First 24 h After Primary Percutaneous Coronary Intervention in Patients With ST-Segment Elevation Myocardial Infarction: The ATLANTIC-H²⁴ Analysis.

OBJECTIVES The aim of this landmark exploratory analysis, ATLANTIC-H(24), was to evaluate the effects of pre-hospital ticagrelor during the first 24 h after primary percutaneous coronary intervention (PCI) in the ATLANTIC (Administration of Ticagrelor in the cath Lab or in the Ambulance for New ST elevation myocardial infarction to open the Coronary artery) study. BACKGROUND The ATLANTIC trial in patients with ongoing ST-segment elevation myocardial infarction showed that pre-hospital ticagrelor was safe but did not improve pre-PCI coronary reperfusion compared with in-hospital ticagrelor. We hypothesized that the effect of pre-hospital ticagrelor may not have manifested until after PCI due to the rapid transfer time (31 min). METHODS The ATLANTIC-H(24) analysis included 1,629 patients who underwent PCI, evaluating platelet reactivity, Thrombolysis In Myocardial Infarction flow grade 3, ≥ 70% ST-segment elevation resolution, and clinical endpoints over the first 24 h. RESULTS Following PCI, largest between-group differences in platelet reactivity occurred at 1 to 6 h; coronary reperfusion rates numerically favored pre-hospital ticagrelor, and the degree of ST-segment elevation resolution was significantly greater in the pre-hospital group (median, 75.0% vs. 71.4%; p = 0.049). At 24 h, the composite ischemic endpoint was lower with pre-hospital ticagrelor (10.4% vs. 13.7%; p = 0.039), as were individual endpoints of definite stent thrombosis (p = 0.0078) and myocardial infarction (p = 0.031). All endpoints except death (1.1% vs. 0.2%; p = 0.048) favored pre-hospital ticagrelor, with no differences in bleeding events. CONCLUSIONS The effects of pre-hospital ticagrelor became apparent after PCI, with numerical differences in platelet reactivity and immediate post-PCI reperfusion, associated with reductions in ischemic endpoints, over the first 24 h, whereas there was a small excess of mortality. (Administration of Ticagrelor in the cath Lab or in the Ambulance for New ST elevation myocardial infarction to open the Coronary artery [ATLANTIC, NCT01347580])