Objective To evaluate the myocardial protective effects of intracoronary(IC)adenosine infusion in patients with coronary heart disease during percutaneous coronary intervention(PCI).Methods A total of 111 enrolled patients were randomised to receive infusions of saline(control group,55 patients)or adenosine(adenosine group,56 patients).10 mL saline(control group)or 300 ?g adenosine(adenosine group)was given by intracoronary(IC)injection within 1 minute.The peak level of ST-segment elevation in IC electrocardiograms(IC-ECG)and the peak level of cardiac triponin I(cTnI)was analyzed and left ventricular ejection fraction(LVEF)was measured.For the patients with acute myocardial infarction(AMI),coronary flow of the infract-related artery was assessed by the method of thrombolysis in myocardial infarction grading.The peak level of sum ST-segment resolution(STR)was measured after one hour of PCI.Results The peak level of serum cTnI in adenosine group was lower than the control group(P

BACKGROUND:The early reperfusion of the infarct-related artery in acute myocardial infarction (AMI) may significantly improve the symptoms and prognosis of patients.However,reperfusion is also followed by ischemia-reperfusion injury and there are no very effective ways to manage this severe problem at present.OBJECTIVE:To evaluate the protective effects of intracoronary adenosine infusion on myocardium in patients with AMI during percutaneous coronary intervention(PCI).DESIGN:Double-blinded and randomized controlled study.SETTING:First Hospital of Hebei Medical University and Third Hospital of Shijiazhuang City.PARTICIPANTS:The clinical triel was performed in 50 eligible patients at the Department of Cardiology,the First Hospital of Hebei Medical University and the Third Hospital of Shijiazhuang City from December 2004 to April 2006.Patients were eligible if they were age 30 years or older and admitted with ST-segment elevation myocardial infarction (STEMI).The diagnosis of STEMI was based on episodes of chest pain persisting at least 30 minutes but no longer than 12 hours and proving unresponsive to nitrates,electrocardiogram (ECG) ST-segment elevation of at least 2 contiguous ECG leads,and 2-fold creatine kinase (CK) elevation above the maximum peak in the normal range.The physicians obtained written informed consent from each patient.The patients were randomly assigned into two groups:those who received intra-coronary adenosine (23 patients) and those who received placebo (saline,27 patients).There were no significant differences between two groups in general condition,characteristics of coronary angiograms and intervention procedure(P＞0.05).METHODS:After the patients were admitted in hospital,general emergence managements were given.All patients received 300 mg aspirin and 300 mg clopidogrel. While the patients remained stable,the left and right coronary arteriography was done before the balloon was inflated.10 mL saline (control group) or adenosine (300 μg+10 mL saline) was immediately given by intracoronary injection within one minute.Then the stenting was performed.Coronary flow of the infarct-related artery (IRA) was assessed by the method of thrombolysis in myocardial infarction (TIMI) grading.MAIN OUTCOME MEASURES:①The peaks of serum levels of cardiac biomarkers were assessed every 4 hours in the first day of admission and then every day up to discharge.②The 12-lead ECG was done 1 hour before coronary angiography and after PCI,the sum of ST-segment resolution (STR) was calculated.③The left ventricular ejection fraction (LVEF) was calculated and measured by echocardiogram on the 3rd day and the fourth week after PCI in modified Simpson's method.RESULTS:All of 50 patients with AMI were involved in the final analysis.①Cardiac biomarkers and sum of STR:The peak levels of serum CK,CK-MB and cardiac troponin Ⅰ (cTnI) in adenosine group were significantly lower than those in control group (t=2.31,z=2.83,2.22;P＜0.05).Sum of STR in one hour after PCI of adenosine group were significantly higher than those in control group (z=2.10,P＜0.05).The lower level of the markers in adenosine group showed the mild myocardial injury.The infarcted patients with more rapid ST-segment resolution in adenosine group meant the better recovery in the electrocardiogram.②Left ventricular function:LVEF at the fourth week of PCI (both adenosine and control group) were better than those on the third day (t=1.45,2.30;P＜0.01).LVEF in adenosine group were significantly higher than control group on the fourth week after PCI.TIMI flow:TIMI 3 flow in the two groups was 22 patients for control group and 19 patients for adenosine group.There was no significant difference between the two groups(P＞0.05).③Side-effect:Four(17.39%) patients in adenosine group and 1(3.70%) patient in control group developed significant sinus bradycardia requiring pacing.However,the incidence of bradycardia requiring pacing was not significantly different between the two groups(Fisher exact,P=0.129).CONCLUSIONS:Intracoronary adenosine infusion during PCI significantly alleviated ischemia-reperfusion injury and improved the left ventricular function in AMI.Intracoronary adenosine infusion in patients with AMI during PCI was safe and feasible.