Impact Of Postconditioning During Primary Percutaneous Coronary Intervention On Infarct Size And Cardiac Function In ST-segment Elevation Myocardial Infarction

ST-segment elevation myocardial infarction has become the main disease threatening human health for its high disability and mortality. At present, most of countries recommend the reperfusion therapy in the early acute STEMI(<12h). A large number of evidence-based medical evidence suggest that reperfusion therapy, especially percutaneous coronary intervention(PCI) therapy, can reopen the infarct related artery(IRA) timely and effectively, reperfuse the infarction myocardium, so as to save dying myocardium, reduce myocardial remodeling and improve the prognosis of the patients. However, reperfusion is like a double-edged sword, which can make ischemic myocardium obtained the blood supply in a timely manner, on the other hand, with the restoration of blood supply, it can cause reperfusion injury in myocardial cells level. People have proposed some cardiac protection strategy including ischemic preconditioning(IPC) and ischemic postconditioning(IPOC). Ischemic postconditioning means applying brief cycles of ischemia-reperfusion immediately after a long time of coronary occlusion before fully reopening the culprit coronary artery. Most of the previous trails showed that ischemic postconditioning can significantly reduce the infarction size(IS), reduce the reperfusion injury. But there are still some trails came to the opposite conclusion. Obviously, the effection of IPOC is influenced by many factors, and the optimal procedure and opportunity of IPOC is still inconclusive.Objective:This study aimed to investigate the impact of multiple balloon inflation during PCI for acute ST segment elevation myocardial infarction on enzymatic infarct size and left ventricular ejection fraction by the method of retrospective study. Accordingly, we aimed to determine whether this may have served as a real-world analogue for IPOC.Method:We conducted a retrospective chart review of all patients who presented to the Hebei General Hospital Heart Center between October 2011 to October 2014, visiting to in line with "Chinese patients with acute ST-segment elevation myocardial infarction diagnosis and treatment guidelines in 2010" on the diagnostic criteria for STEMI undergoing primary PCI. We included patients if they:were first STEMI adults who were 18-80 years of age; had symptoms suggesting acute myocardial ischemia lasting≥30 min, rest or sublingual nitroglycerin after symptoms not alleviate the symptoms; had ST-segment elevation≥0.1 m V in≥2 contiguous leads or had new left bundle branch block; had an occluded infarct-related artery(IRA) with TIMI 0 flow on coronary angiography; had a Ren Trop grade 0 collateral to the infarction area; had sustained chest pain onset to coronary artery opening<12 hours. We excluded patients who with non ST-segment elevation myocardial infarction; who had been performed thrombolytic before PCI; with old myocardial infarction, PCI and coronary artery bypass grafting history; who with chronic heart failure, cardiac function grade II or above; who with occurrence cardiogenic shock, heart disease arrest; who with the myocardial infarction angina pectoris before 48h; who with heavy thrombus burden and application of thrombus aspiration; who with IRA for left main disease or other coronary occlusion with left main coronary artery serious stenosis; who with IRA TIMI flow has reached more than 2 or IRA has a level 2 or above collateral circulation; who with lesions of anatomical structure is not suitable for PCI treatment(including left main lesion serious serious, 3 branches of blood vessel lesions, severe calcified tortuous lesions); interventional treatment for other non vascular IRA; associated with other serious diseases. The study population was divided into patients receiving≤2 balloon inflations during primary PCI in the IRA(considered minimum range for achieving patency/stent placement [CON group]) and patients receiving ≥ 3(IPOC group). Two groups of patients were compared with age, cardiovascular risk factors, drinking history, symptom onset to the vessel opening time, infarction related position, the infarct related artery, balloon inflation times and time, collectting creatine kinase(CK) and creatine kinase-MB(CK-MB) release peak, left ventricular septal thickness(IVSd), left ventricular posterior wall thickness(LVPWd), left ventricular end systolic diameter(ESD), left ventricular end diastolic diameter(EDD), left ventricular ejection fraction(LVEF).Results:This research included 98 patients, including 52 cases of CON group, 46 cases in IPOC group, there was no significant difference between the two groups on hypertension, diabetes, hyperlipidemia prevalence rate comparison and drinking history comparison.There was statistically significant difference between the two groups of patients on age and smoking history.There was no statistically significant difference between the two groups of patients on symptom onset to the vessel opening time, infarction related artery, average balloon time, operation pressure, the incidence of no-reflow, slow blood flow, intraoperative acute thrombosis, glycoprotein IIb/IIIa receptor antagonist using rate during hospitalization, comparison of conventional medication during hospitalization。Compared with the peak of CK and CK-MB release of the two groups patients during hospitalization, the difference was statistically significant(2541.50 ± 571.77IU/L vs 2181.08 ± 385.37IU/L, P < 0.05)(290.12 ±36.45U/L vs 270.91±30.71U/L, P<0.05).There was no statistically significant difference between the two groups during hospitalization for IVSd, LVPWd, ESD, EDD, LVEF. There was statistically significant difference of EDD and LVEF for 3 months after PCI compared between the two groups of patients(50.23±3.51 mm vs 47.65±3.48 mm, P<0.05),(49.50±7.38% vs 52.13±7.07%, P<0.05), and there was no statistically significant difference compared to the rest of the parameters.Comparison of two groups of patients with MACCE during hospitalization and 3-month follow-up, the difference was no statistically significant.Conclusions:The present study suggests that the use of≥3 balloon inflations during PPCI reduces enzymatic IS in patients with STEMI, reduce reperfusion injury and can improve left ventricular function after reperfusion for 3 months after PCI and inhibit the ventricular remodeling, improve left ventricular ejection fraction and multiple balloon inflations in primary PCI is safe and effective.