Cardioprotection Of Nicorandil In Patients With Acute Myocardial Infarction

Objective: To investigate the impact of oral nicorandil treatment oncardiovascular events in acute ST-segment elevation myocardial infarction(STEMI) patients compared with isosorbide mononitrate(ISMN),further toexplore the cardioprotection of nicorandil on the infarcted myocardium.Methods: From December2009to June2011, a total of one hundred andeighty six consecutive patients with first STEMI were enrolled in this study.They were hospitalized within12hour after AMI onset. Taking loading doseof water soluble aspirin300mg and clopidogrel600mg,we performedcoronary angiography immediately to the patients who were suitable toemergency percutaneous coronary intervention (PCI).There were ninety fourcases for emergency percutaneous coronary intervention (PCI),the others withinfarct related artery(IRA) loading a mass of thrombosis for elective PCI weretreated with20ml tirofiban injected into the IRA preventively.Angiographywas done after90minutes of thrombolysis therapy. According to thrombolysisin myocardial initial (TIMI) grade in infarct-related artery,21cases with IRAblood flow less than TIMI3were for rescue PCI, and the others were forelective PCI.Patients who underwent coronary angiography were divided intonicorandil group(n=91) and isosorbide mononitrate control group(n=95)randomizely.No significant differences in age, gender, body mass index,prevalence of coronary risk factors, or symptom to admission time betweenthe two groups;myocardial enzymes were dynamicly observed,and the peakof CK and CK-MB,serum creatinine,serum BNP were compared. Itappears that the study cohort had been more strictly treated with secondaryprevention medications in the present study, as the prevalence ofco-administered cardioprotective drugs such as antiplatelets, ACE inhibitors,angiotensin II receptor blockers (ARBs), β-blockers, and statin. Patients were randomized to receive either nicorandil (5-10mg tid) or isosorbide mononitrate(ISMN:60mg qd) for6months, if necessary taking nitroglycerin sublinguallyor intravenously in a short time. WMSI(wall motion score index), LVEF(leftventricular ejection fraction), LVEDV(left ventricular end diastolic volume),LVESV(left ventricular end systolic volume), LVESVI(left ventricular endsystolic volume index)were observed and recorded by echocardiography at6months after PCI in order to assess the effects of oral nicorandil on wallmotion and the recovery of ventricular function. We also recorded ventricularlate potential, QT interval dispersion and the occurrence of arrhythmia throughholter electrocardiogram for24hour,then quantificate of arrhythmias usingCurtis-Walker scoring systems.We measured the myocardial infarction areavia99mTc-MIBI-SPECT and recorded recurrent angina pectoris.Statisticalanalysis was performed using the SPSS system Version17.0.Results:1There was no significant difference between the two groups about sex, age,smoking, diabetes, hypertension, hypercholesterolemia, systolic bloodpressure, diastolic blood pressure, heart rates, myocardial enzymes,serumcreatinine, serum BNP and hs-CRP; in addition, there were no significantdifferences about symptom to admission time, heart function and the casesof emergency PCI in all patients; no significant differences were foundabout the oral drugs used after PCI between the two groups.2Echocardiography at6months after PCI showed that, compared to controlgroup,WMS(I1.40±0.19vs.1.47±0.20,P=0.031), LVESV(I32.24±4.87vs.34.79±5.37ml/m2,P=0.001) were significantly lower in nicorandilgroup,LVEF was no significant difference between the two groups(P=0.103).3Compared to control group, the area of myocardial infarction in nicorandilgroup was much lower (15.44±4.12vs.17.45±4.56), differences weresignificant in statistics(P=0.002).45cases(5.5%) of arrhythmia happened in nicorandil group,13cases(13.7%) happened arrhythmia in control group.However, the quantification of arrhythmias using Curtis-Walker scoring systems was not foundsignificant change (P=0.059).5The incidence of ventricular late potential in control group (29.5%)within6months after PCI was more than that in nicorandil group(16.5%)obsviously (P=0.036).6The QT interval dispersion in nicorandil group and control group were(41.27±8.70) vs.(44.39±9.21)ms, differences were significant in statistics(P=0.019).7The cases of recurrent angina pectoris in nicorandil group(21) were lessthan control group(31), but no significant difference was found (P=0.153).Conclusion: Compared with isosorbide mononitrate (ISMN),oralnicorandil can effectively decrease infarction area after PCI in acute STEMI,prevent left ventricular remodeling,reduce the incidence of ventricular latepotential and QT interval dispersion in a long term. In addition,nicorandilmay have equivalent or better antianginal effect than ISMN.