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Paper text:
the efficacy of glycoprotein iib / iiia ( gp iib / iiia ) inhibitors in high risk , non - st - segment elevation myocardial infarction ( nstemi ) acute coronary syndrome ( acs ) patients has been well established .
according to the updated american college of cardiology foundation / american heart association ( accf / aha ) guideline , it is recommended in high risk patients undergoing invasive strategy that gp iib / iiia inhibitors should be chosen as the second antiplatelet therapy ( ia ) . however , whether up stream use of gp iib / iiia could be better than provisional use in the cath lab remained to be answered .
most recently , the results of two meta analyses have been published , , showing that : ( 1 ) in nste acs , treatment with upstream , small - molecule gp iib / iiia inhibitors provided a significant , but modest ischemic benefit when compared with initial placebo ; ( 2 ) compared with delayed , selective use at percutaneous coronary intervention ( pci ) , early upstream use was associated with a trend toward fewer ischemic events .
however , these modest benefits were associated with an increased risk of bleeding . as the meta - analysis data were from studies on different brands of gpi , including tirofiban , etifibatide , lamifiban , and abciximab ,
it is still of interest to know whether a specific gp iib / iiia inhibitor would have a specific effect , especially in a chinese population .
consequently , we decide to perform a randomized , controlled clinical trial to compare early ( prior to transfer to the catheterization laboratory ) vs. late ( at the time of pci ) initiation of intravenous tirofiban ( which is the only gpi available in china ) in nstemi acs patients undergoing pci .
our primary aim will be to compare , in nste acs patients , the efficacy of initiating tirofiban 12 h before pci ( 10 g / kg bolus , followed by continuous infusion at 0.15 g / kg per min for 1224 h after pci ) vs. initiating tirofiban at the time of pci ( 10 g / kg bolus , followed by continuous infusion at 0.15 g / kg per min for 1224 h after pci ) .
the clinical end point is the composite endpoint , including myocardial infarction , target lesion revascularization and death at 30 days .
the angiographic endpoints are the prevalence of thrombolysis in myocardial infarction ( timi ) iii flow , timi myocardial perfusion grade ( tmpg ) , and corrected timi frame counting ( ctfc ) before and after pci .
consecutive 500 in - patients with a diagnosis of mid to high risk nste acs patients will be selected prospectively .
recruited patients will be asked to participate in a face to face interview , informed consent for follow - up contact will be obtained from the patients at enrollment .
open - label randomization will be performed once the eligibility criteria are met . a 1 : 1 computer - generated , random sequence supplied by an academic statistician , without blocking or stratification , will be used .
questionnaires will be developed for the study - wide use including three parts : form 1 , basic information ; form 2 , pci procedures ; form 3 , follow - up information .
etn - step : early administration of tirofiban in mid to high risk patients with non - st elevation , acute coronary syndrome referred for percutaneous coronary intervention ; nste acs : non - st segment elevation acute coronary syndrome ; pci : percutaneous coronary intervention ; timi : thrombolysis in myocardial infarction .
etn - step : early administration of tirofiban in mid to high risk patients with non - st elevation , acute coronary syndrome referred for percutaneous coronary intervention ; nste acs : non - st segment elevation acute coronary syndrome ; pci : percutaneous coronary intervention ; timi : thrombolysis in myocardial infarction .
times of tirofiban administration and interventional procedures , hospital - associated outcomes and follow - up information after discharge will be recorded .
completed questionnaires will be sent to the data management center , where they will be checked for possible errors or omissions by professionals
. two percent of the questionnaires will be verified , at random , by comparing the information with original medical records of in - patients and follow - up calls to selected outpatients .
any resulting data queries will be referred to the originating site before the forms are processed and computerized audit checks will be performed after data are is double inputted .
errors and illogicalities of selected data elements will be forwarded to the originating site for correction .
the statistical significance of the differences between interventional group and control group with respect to the composite end point and its components will be assessed using logistic regression analysis .
all tests will be two - sided , and statistical significance declared if p < 0.05 .
the etn - step study will be the first randomized , prospective study to evaluate the upstream vs. downstream administration ( dispensing ) of tirofiban in chinese acs patients undergoing pci .
firstly , we believe that it is more meaningful to address the time issue of gp iib / iiia administration in high acs patients . therefore , when screen the study subjects , we will use the timi risk score system to define the mid to high risk acs patients .
although such a risk evaluating system may not be an optimal model in predicting the outcomes of acs patients , it is easy to calculate , and furthermore , the results of the study may be more valuable in clinical practice by using such criteria .
secondly , the dose of tirofiban used in this study may be different from that normally recommended , however , it is currently the dose we are routinely administering in the clinic . in all , the findings of the etn - step study will provide insight into the optimal timing for tirofiban initiation in mid to high risk acs chinese patients undergoing pci .
as a member of glycoprotein iib / iiia ( gp iib / iiia ) inhibitors , tirofiban had been shown to improve myocardial reperfusion and clinical outcomes in patients undergoing percutaneous coronary intervention ( pci ) , but the optimal timing of administration of tirofiban remains unclear . in order to compare the effects of upstream versus downstream administration of tirofiban in chinese patients with mid to high risk , non - st elevation acute coronary syndrome ( acs ) referred for pci , a multi - center , randomized , controlled , prospective study will be conducted . 
 a total of 500 mid to high risk , non - st - segment elevation myocardial infarction ( nstemi ) acs patients will be recruited for this study . 
 patients will be randomized to tirofiban upstream administration group ( initiated 12 h before pci ) and tirofiban downstream administration group ( initiated at cath - lab after angiography ) . 
 thrombolysis in myocardial infarction ( timi ) flow grades , timi myocardial perfusion grades ( tmpg ) , and corrected timi frame counting ( ctfc ) before and after pci , as well as clinical outcomes during the hospital stay , and within 30 days after pci will be compared between the two groups . 
 this study will provide evidence on the optimal timing for initiating administration of tirofiban in mid to high nstemi acs subjects undergoing pci .