The Preventive Effect And Safety Of Intracoronary Injection Nicorandil On No Reflow For STEMI Patients Undergoing Primary PCI

Objective: Primary percutaneous coronary intervention can open the blood flow of infarction related arteries early,effectively and continuously,which can decrease myocardial infarction size,protect cardiac function and reduce the major adverse cardiac events.Patients with acute ST-elevation myocardial infarction will get much benefits if they take primary PCI within the effective time window.But the coronary microvascular dysfunction often takes place during or after primary PCI in some patients,which means the infarct related myocardial does not recieve enough reperfusion,so called no reflow phenomenon.NRP can lead to heart failure,malignant arrhythmia and even cardiac death.Primary percutaneous coronary intervention is the greatest therapeutic regimen of revascularization for STEMI patients for now.And people will get better clinical outcome if we could prevent and treat no reflow in coronary arteries especially in catheter room.Nicorandil is a new drug in treating angina and has dual pharmacological action.One is performing as an ATP sensitive K-channel opener,which can increase the change of K and Ca leading to the relaxation of vascular smooth muscle and dilating blood vessel finally.The other is the function of Nitrates-like,which is able to dilate coronary microcirculation further to improve the myocardial perfusion and decrease the cardiac preload.This research aims to observe the preventive effect and safety of intracoronary injection nicorandil on no reflow of coronary arteries for STEMI patients undergoing primary PCI and the improvement in myocardial reperfusion.Methods: This research adopted the prospective,randomized and controlled method.112 Patients suffering from acute ST-segment elevation myocardial infarction within 12 hours for the first time in Affiliated Hospital of Hebei University,and at the same time agreeing to receive primary percutaneous coronary intervention were enrolled in this study from January2019 to December 2019.All patients got coronary angiography firstly,according to whether nicorandil was administered intracoronary when the vessel had front blood flow after the guiding wire or balloon being got through the infarct related arteries,these patients were all randomly divided into two groups: the nicorandil group(n=56)received intracoronaryadministration of 6mg nicorandil and 10 ml saline,and control group(n=56)received 10 ml saline only,then all patients got standard PCI if necessarily.All patients took the medical treatment according to the relevant myocardial infarction guidelines.Collect all patients baseline clinical date including age,gender,hypertension,diabetes mellitus,hyperlipidemia,the history of smoking,the ratio of Killip I classification and the white blood cell count before the operation.Record the indexes as follows: 1 the parameters related to intervention: the time from onset to balloon dilatation,the ration of infarct related artery to right coronary artery,the number of stents,the length of stents,the diameter of stents,the dosage of contrast agent,the thrombolysis in myocardial infarction(TIMI)before and after PCI,the corrected TIMI frame count(CTFC),TIMI myocardial perfusion grade(TMPG)and the incidence of no reflow after PCI.And record the blood pressure,heart rate and the incidence of arrhythmia when injecting nicorandil.2 the indexes of myocardial enzymes: the levels of CK-MB and cTnI were measured every 6 hours after PCI,and the peak value was recorded.3 the indexes related to electrocardiography and echocardiography: the complete ST resolution(STR)in both groups at 90 mins after PCI.Cardiac function was evaluated by left ventricular ejection fraction(LVEF)through echocardialgraphy at one week after PCI.4 The proportion of major adverse cardiac events: angina pectoris during the period of hospitalization and MACEs for follow up visit at one month after PCI including recurrent myocardial infarction,target vessel revascularization and cardiac death.All calculations were analyzed with the help of SPSS statistical software(version 22.0),and the P Value of less than 0.05 were considered statistically significant difference.Results:1 The baseline clinical data including age,gender,high blood pressure,diabetes mellitus,hyperlipidemia,the history of smoking,the ratio of Killip I classification and white blood cell count had no significant difference between the two groups(all P>0.05).2 For the characteristics related to PCI in these two groups,the proportion of TMPG3 after PCI in nicorandil group was higher than that in control group(91.1% vs.71.4%,P=0.035),nicorandil group was lower in the incidence of no reflow than that in control group(8.9%vs.29.6%,P=0.046),the difference was statistically significant.As for the indexes of the time from onset to balloon dilatation,the ration of infarct related artery to right coronary artery,the number of stents,the length of stents,the diameter of stents,the dosage of contrast agent,the proportion of TIMI3 before PCI and CTFC after PCI,there was no significant difference(all P>0.05).The proportion of TIMI3 in both groups all increased after PCI(94.6% vs.91.1%,P=0.475),but it didn't reach the significant difference(P>0.05).The blood pressure and heart beat in all patients were in stable and safe range when they were giving nicorandil,at the same time there was no reperfusion arrhythmia occurring during the operation period.3 The comparison of myocardial enzymes of laboratory examination between the two groups,the peak value of CK-MB(89.6±36.8 vs.90.7±35.2,P=0.442)and cTnI(12.96±2.23 vs.12.14±2.44,P=0.767)were lower in nicorandil group than those in control group,but the statistical was not different significantly(all P>0.05).4 The indexes related to electrocardiography and echocardiography,the ration of complete ST-segment resolution recorded at 90 mins after PCI in nicorandil group was much better than control group(83.9% vs.67.9%,P=0.028),which reached significantly difference(P<0.05).The left ventricular ejection fraction was similar in the two groups(58.87±2.35% vs.57.63±3.66%,P=0.298)at one week after PCI,there was no significant difference(P>0.05).5 The difference of following up in major adverse cardiac events,there were 3 patients in nicorandil group and 8 patients in control group appearing angina pectoris during hospitalization after PCI.As for the one-month follow up,one case occurring stent thromboses need to take the target vessel revascularization in nicorandil group,while there were 2 cases occurring recurrent myocardial infarction and 3 cases of stent thromboses needing TVR,the difference was no statistically significant(all P>0.05).Conclusion: Intracoronary injection of nicorandil shows the preventive effect on improving the myocardial reperfusion in patients with STEMI undergoing primary PCI to some extent and decreases the incidence of no reflow.