Objective     To determine the effect of ticagrelor on the coronary blood flow and prognosis in patients with acute ST-segment elevation myocardial infarction (ASTEMI) before undergoing emergency percutaneous coronary intervention (PCI).    Methods    A total of 127 patients who were diagnosed with ASTEMI undergoing emergency PCI in our Bethune International Peace Hospital from June 2014 to May 2015 were enrolled in this study. According to taking different drugs before PCI

they were allocated to ticagrelor group (n=62

180 mg) and clopidogrel treated group (n=65

600 mg). Their baseline conditions

coronary blood flow

and major adverse cardiac events (MACE

including acute and subacute stent thrombosis

recurrent angina and myocardial infarction

“criminals” vessel revascularization

re-hospitalization and death) during both hospitalization and 6-month follow-up were compared between the 2 groups.     Results     There were no significant differences in baseline data

angiographic characteristics before PCI

peak value of myocardial enzyme and left ventricular ejection fraction after PCI between the 2 groups (P0.05). Compared with the clopidogrel group

the percentage of no-reflow in infarctrelated artery (IRA) (15.2%

3.2%)

and corrected TIMI frame count (cTFC) of IRA after PCI (28.4±13.6

23.2±7.4) were significantly decreased in the ticagrelor group (P0.05). The peak time of myocardial enzyme (19.0±8.3

16.0±5.9 h) and percentage of STsegment elevation resolution (STR) ≥50% (76.9%

91.9%) in the ticagrelor group were significant different with those of clopidogrel group (P0.05). The composite endpoint event rate was significantly lower in the ticagrelor group than the clopidogrel group in 6 months of follow-up (P0.05).    Conclusion     Loading dose of ticagrelor before emergency PCI improves coronary blood flow

myocardium reperfusion and clinical prognosis.