Influence Of The Collateral Circulation On The Prognosis In Patients With Acute Myocardial Infarction

BackgroundAcute myocardial infarction, due to severe myocardial ischemia and hypoxia, results in myocardial necrosis even sudden death. Animal experiments and clinical trials found that coronary collateral circulation did have a significant protective effect on the infarct zone, reduce cardiac dysfunction and the incidence of major adverse events, but so far there is still no consistent conclusion. Most Chinese and internal studies have focused on protective effects of the collateral circulation on the myocardium. Yet for the influence factors of its formation and the mechanisms of influence on the prognosis of AMI is remains unclear. This paper studies the mechanism of the formation of collateral circulation, its protective effect against myocardial ischemia and prognostic significance, according to results of coronary angiography, echocardiography, serum creatine kinase and cardiac remodeling and other aspects of observation, in order to improve treatment strategies for acute myocardial infarction.ObjectiveTo investigate the role of collateral circulation, factors of affecting its formation and the influence of collateral circulation on the prognosis in patients with acute myocardial infarction.Materials and methods1. Objective of the research130 patients with AMI from Department of Cardiology of the Provincial Hospital Affiliated to Shandong University underwent the coronary angiography from September 2013 to August 2014, including male 101 cases, female 29 cases, whose mean age is 57 ± 11.1.1 Selection criteriaMeat any two of which can be confirmed according to the WHO diagnostic criteria for ischemic heart disease:(1) Typical ischemic symptoms of the chest pain over 30 minutes; (2) ST-segment≥1mm elevation (or depression) on two to three adjacent leads of the ECG or emerging CLBBB graphics; (3) CK creatine kinase or creatine kinase isoenzyme CK-MB increases up to more than two times the upper limit of the normal value.1.2 Exclusion criteria:(1) Recent major trauma, major surgery or bleeding; Patients with stroke or cerebral hemorrhage;(2) Patients with severe arrhythmias, cardiomyopathy, valvular heart disease, congenital heart disease;(3) Patients with severe systemic disease and life expectancy of less than 1 year, such as cancer, multiple organ failure.2. Clinical data collection(1) Basic clinical data collection:Age, gender, smoking history, history of the hypertension, diabetes mellitus, heart function and so on.(2) Laboratory tests:CK and CK-MB peak concentration.(3) Echocardiographic findings:LVEF, LVEDV and the wall motion score.(4) Major cardiovascular events, including post-infarction angina, arrhythmias, reinfarction, severe heart failure and sudden cardiac death and other readmission of cardiac reasons.3. Introduction of biochemical indicator detection method3.1 Main instruments and laboratory equipment Cobas-6000 ECL instrument Roche Cobas-P8000 Automatic biochemical analyzer Roche3.2 Detection methodAll patients were determined the CK and CK-MB every two hours after admission and pathogenesis during the first 24 hours, then determined once a day and record cardiac enzyme peak concentration. Collect the fasting peripheral venous blood, place in a centrifuge and centrifuge at 3000 rev/min for 20 minutes. The first sample was used to determine the CK and CK-MB and the other was for FPG, TC, TG, HDL-C and LDL-C.CK and CK-MB were tested by electrochemiluminescence; TC and TG were tested by enzymatic; HDL-L and LDL-C were tested by ultracentrifugation combined with ALBK; FPG was tested by glucose oxidase method.4. Coronary angiography acquisition4.1 Coronary angiography equipmentThe coronary angiography equipment contains X-ray cardiovascular imaging machine, high-pressure syringe, ECG and pressure monitoring system, imaging workstation and other angiography equipment.4.2 Coronary angiographyThe left and right coronary were respectively administered angiography using Judkins method. The left coronary artery took 4 positions (RAO30°+Caudal30°, RAO20°+Cranial30°, LAO45°+Cranial25°, LA045°+Cauda130°, Caudal). The right coronary artery took 2 positions (LAO30°, Cranial). Angiography time was not less than 6 to 8 cardiac cycles and the image should clearly showed the main coronary artery, its main branches’vascular tree and the vascular openings. Observe if there was any collateral circulation coming from the same side of the same branch, different branches of ipsilateral or contralateral coronary of the severe stenosis or occlusion of coronary during the coronary angiography. Surgery was made by two deputy chief physician experts.Angiography results were evaluated by two experienced specialist. Rating according to the Rentrop method,0-No visible collateral circulation; 1-Minimal collateral vessels, blood flow intrusion only found in the infarct-related artery distal branches; 2-Adequate collateral circulation, blood could be partially filling IRA; 3-Rich collateral vessels. This study was divided into 2 groups. Group A (the existence of collateral circulation group):2-3 points,43 cases. Group B (without collateral circulation group):0-1 points,87 cases.5. Statistical MethodsData were processed by SPSS 10.0 statistical software package. The measurement data were defined as X ± SD while the differences between groups using two independent samples t-test. And the count data were expressed as a percentage and compared by means of the chi-square test. P<0.05 was defined to be statistically differences.Results1. Basic clinical data analysis:Two groups showed no significant differences in age (57.1±10.5VS57.0±10.9), gender, diabetes (18.6%VS18.7%), history of hypertension(53.5%VS51.7%), smoking history (51.2% VS 58.6%), cardiac function and other aspects (P>0.05). But the diabetes (11.63% VS 29.89%) between the two groups have differences. Q-wave myocardial infarction in group A is lower than in group B (58.1%VS77%), the incidence of pre-infarction angina and multivessel disease in group A higher than in group B (69.8%VS51.7%). There are significant differences among the data sets above (P<0.05)2. Blood biochemistry analysis:There were no significant differences between two groups in FPG (7.92±3.05 VS 9.2U4.61)、TG (1.63±0.81 VS 1.77±1.50)、TC (4.14±1.04 VS 4.47±1.05)、HDL-C(1.20±0.39 VS 1.18±0.38)、LDL-C (3.54±1.15 VS 3.72±1.07)3. There was a significant difference between the two groups in CK peak concentration and cardiac function.4. Major adverse cardiovascular events and complications were statistically different between the two groups.Conclusion1. Age, sex, smoking history, history of hypertension, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol had no significant influence on the formation of coronary collateral circulation.2. The formation of collateral circulation was a common result of many factors, and the degree of coronary stenosis was a major determinant of collateral circulation.3. Angina before myocardial infarction prompts rich CC while post-MI angina tips high Mace.4. The formation of collateral circulation of preinfarction angina can protect acute ischemic myocardium, and, to a certain extent, reduce the range of MI, protect the left ventricular function, prevent the ventricular aneurysm and reduce the incidence of major cardiovascular events and complications.