Cardioprotection Of Oral Nicorandil Treatment By Reducing Ischemic-reperfusion Injury In Patients With Acute ST-elevation Myocardial Infarction Undergoing Primary PCI

Objective: To explore the cardioprotection of oral nicorandil treatmentby reducing ischemic-reperfusion injury in patients with acute ST-elevationmyocardial infarction undergoing primary PCI by observing myocardialdamage, infarct size, coronary microcirculation perfusion, arrhythmia andcardiac function.Methods: From December2010to December2012, a total of87consecutive patients with first-time STEMI (63males,24females), aged63.16±10.20years old were enrolled in this study. Total of87patients withoutpreinfarction angina were randomly divided into two groups: nicorandil group(oral nicorandil, n=42) and control group (only PCI, n=45). A preoperativeevaluation was made in all patients. Taking loading dose of aspirin300mg andclopidogrel300mg, all patients suitable to primary percutaneous coronaryintervention underwent coronary angiography immediately. The patients innicorandil group received dose of nicorandil15mg immediately afteradmission. All patients underwent PCI within12hours after AMI onset.Patients in both two groups received standard treatment of acute myocardialinfarction, including absolutely lying on bed, oxygen inspiration, ECGmonitoring, oral drugs taking and subcutaneous injection of low molecularweight heparin calcium. The patients in nicorandil group received5mg oralnicorandil three times a day after PCI, while patients in control group received60mg oral isosorbide mononitrate sustained-release tablets once a day.Clinical data including gender, age, coronary risk factors and vital signs onadmission were collected. Peak value of cTnI, serum creatinine, blood lipidand ECG changes were observed and compared. The infarct-related artery,corrected TIMI frame count (CTFC) and reperfused arrhythmias were recorded during PCI. Occurrence of arrhythmias was recorded by Holter atone week after PCI, then quantificated by Curtis-Walker scoring systems. Leftventricular ejection fraction (LVEF), wall motion score (WMS), leftventricular end diastolic volume (LVEDV) and left ventricular end systolicvolume (LVESV) were measured by echocardiography at7days after PCI, andthen wall motion score index (WMSI) and cardiac index (CI) were calculatedin order to assess ventricular function. Statistical analysis was performed bythe SPSS system Version17.0.Results：1There were no statistical differences about sex, age, smoking,hypertension, diabetes, strokes, family history, diastolic blood pressure,systolic blood pressure, heart rates, hypercholesterolemia, serum creatinine,IRA and the oral drugs between the nicorandil group and control group.2It was not found statistically different in the level of cTnI on admissionbetween the nicorandil group and control group. The postprocedural serumlevels of cTnI were higher than that on admission. Levels of cTnI in controlgroup were less than those in nicorandil group at12and24hours after PCI(P=0.023, P=0.036).3CTFC in control group was higher than that in nicorandil group(P=0.011).4Compared with nicorandil group, the incidence of reperfusedarrhythmias in control group was much higher (P<0.05).5Compared with the control group, the incidence of malignantarrhythmia in nicorandil group was lower (P=0.033).6Although the LVEF and CI in nicorandil group within1week after PCIwere higher than those in control group, but without significant differencesbetween the nicorandil group and control group. Echocardiography at7daysafter PCI showed that: compared with the control group, WMSI was lower innicorandil group (P=0.006).Conclusion: Nicorandil can alleviate myocardial injury, improve myocardial microcirculation perfusion, reduce the incidences of reperfusionarrhythmia and postoperative arrhythmia at one week after PCI, as well asprotect cardiac function in acute ST-elevation myocardial infarction.