Clinical Characteristics And Prognosis Of Myocardial Infarction With Non-obstructive Coronary Arteries-Single Center Retrospective Study

Backgrand and objective:Acute myocardial infarction(AMI)and CAG shows suggest that there is no blood flow-restricted disease,such "special AMI" was defined as myocardial infarction with non-obstructive coronary arteries(MINOCA)in"2016ESC Working Group position paper".The guidelines indicate that MINOCA should be considered as a "preliminary diagnosis" and the underlying cause of the clinical symptoms of the patient should be ascertained by improving the relevant examination,then completed the diagnosis and treatment.At present,the cause of MINOCA mainly includes plaque rupture or erosion,coronary artery spasm,and so on.MINOCA causes complex,different studies for the prognostic assessment sometimes appeared conflicting conclusions,while most studies suggest that long-term prognostic of MINOCA was poor.A study shew that non-obstructive CAD patients with ACS follow-up 26 ± 16 months died 4.4%,re-admission 3.8%,comparing with obstructive CAD patients with ACS had no significant difference(P>0.05).Therefore,non-obstructive CAD patients with ACS was in high risk of cardiac ischemic events occurrence.A recent study also showed 126 patients with MINOCA were examined by cardiac magnetic resonance(CMR),87%(109 cases)demonstrated abnormal changing in cardiac structure and/or myocardial tissue,diagnosed with myocarditis,and further diagnosed Takotsubo cardiomyopathy and so on.The purpose of this study is to observe and analyze the patients with diagnosis of AMI and CAG examination showed no obvious coronary vascular stenosis,such as the relevant clinical indicators and prognosis for one year,then improving the MINOCA The prognosis of patients to provide the basis and help.Methods:Retrospective analysis patients from January 2005 to October 2016 who admitted to our hospital diagnosed as AMI and CAG examination confirmed coronary artery normal or stenosis<50%.The general condition,the test index,the characteristics of coronary angiography and the therapeutic use were collected after admission.The end point of the study was a 1-year complex endpoint(including all-cause death,recurrent myocardial infarction,and/or re-admission from chest pain),then analyzed the factors that affected the outcome of the composite endpoint.According to ECG performance,divided into ST-segment elevation myocardial infarction(STEMI)and non-ST-elevation myocardial infarction(NSTEMI),make subgroup analysis.Results:1.General clinical features about MINOCA patients:Patients admitted to our hospital from January 2005 to October 2016,diagnosed as AMI and did CAG examination with a total number of 5474 cases.Patients who met the MINOCA diagnostic criteria accounted for 2.5%(139 cases).Among them,64%(89 cases)of unclear etiology,15.8%(22 cases)of cardiac arrhythmia,10.8%(15 cases)of heart muscle bridge,2.9%(4 cases)of Takotsubo cardiomyopathy,2.9%(4 cases)of intravascular thrombos,2.2%(3 cases)of Hemangioma-like expansion,1.4%(2 cases)of Hypertrophic cardiomyopathy,0.7%(1 case)of vasospasm.The average age of MINOCA patients was 55.80 ± 12.15 years;male patients were more than female patients(69.1%vs 30.9%);The predisposing factors are Hypertension history 52.5%(73 cases),Smoking history 43.2%(60 cases),Diabetes history 9.4%(13 cases);Previous history of cerebrovascular disease 5.8%(8 cases),1.4%of prior myocardial infarction(2 cases).CAG results show Vascular normal 52,5%(73 cases),Vascular mild stenosis(stenosis 1-49%)47.5%(66 cases);After admission,14.4%(20 cases)of patients with cardiac insufficiency(Killip??).Main Hospitalization medicines were aspirin,ADP receptor inhibitors,statins and nitrates,which drugs application rate of more than 90%,and discharge medicine,of aspirin,statin were used more,account for 90.6%and 87.8%,respectively.2.End point and related risk factors analysis for Patients with MINOCA fellow-up 1 year:The incidence of follow-up 1 year composite end point was 12.9%(18 cases),Including 2.2%(3 cases)of death,2.2%(3 cases)of nonfatal recurrent myocardial infarction,and 8.6%(12 cases)of chest pain and rehospitalization.MINOCA patients with composite end point event COX model multivariate survival analysis:Age>60 years(RR = 3.676,95%CI:1.309?10.327,P = 0.013),The highest level of CK-MB at admission(RR = 1.010,95%CI:1.002?1.017,P = 0.008)is an independent risk factor for compound end points in patients with MINOCA within 1 year,Patients were treated with statins(RR = 0.301,95%CI:0.093 to 0.978,P = 0.046)is an independent protection factor for composite end points.3.Comparing Clinical features and prognosis of patients with ST-segment elevation myocardial infarction(STEMI)and with non-ST-elevation myocardial infarction(NSTEMI)(subgroup analysis):The incidence of NSTEMI in MINOCA slightly higher than STEMI patients was 51.8%(72 cases)vs 48.2%(67 cases).Average age roughly the same(54.88 ± 12.89vs56.65 ± 11.45,P = 0.392).There was no significant difference in the proportion of male patients and female patients(P =0.528);NSTEMI group more with hyperlipidemia(27.1%vs 12.5%,P = 0.035);Peak of Creatinine(Cre),High sensitivity C protein(hs-CRP),Creatine kinase(CK),Creatine kinase isoenzyme(CK-MB),Troponin I(TnI)in STEMI group were Higher(P<0.05).CAG examination showed that NSTEMI 51.4%(37 cases)with normal vascular,1-49%vascular stenosis accounted for 48.6%(35 cases),while comparing with STEMI group,there was no significant difference(P = 0.782).Coronary flow TIMI<class II STEMI group 7.5%(5 cases),NSTEMI group 8.3%(6 cases),no difference between the two groups(P = 0.850);hospitalization medicines in the two groups were similar(P>0.05),mainly for aspirin,ADP receptor inhibitors,statins and nitrates(application>90%).When discharge Patients with STEMI group more likely to have statin(94%vs 81.9%,P = 0.03).Followed up 1 year,complex end points of STEMI is 14.9%(10 cases)including:death 1.5%(1 case),nonfatal recurrent myocardial infarction 1.5%(1 case),chest pain and then hospitalized 11.9%(8 cases).In the NSTEMI group is 11.1%(8 cases),including 2.8%(2 cases)of death,2.8%(2 cases)of nonfatal recurrent myocardial infarction,5.6%(4 cases)of chest pain and hospitalization,and no significant difference between the two groups(14.9%vs11.1%,P = 0.505).Conclusion:1.MINOCA prevalence is low,MINOCA patients more young,men dominated.The average age of female patients was higher than male patients,mainly risk factors is hypertension and smoking.The incidence of NSTEMI was higher than STEMI.2.Age>60 years and CK-MB level is death,non-fatal recurrent myocardial infarction and chest pain re-admission independent risk factors,Statins is independent prevent factors.Although MINOCA patients had no significant vascular stenosis,but always with different degrees of myocardial injury,and long-term prognosis is poor,we should pay attention.3.NSTEMI incidence is higher,more with hyperlipidemia,STEMI patients with more myocardial necrosis area,and inflammatory index is high,The use of statins after discharge is more common.There was no significant difference between the two groups at 1 year compplex end point.4.MINOCA typical cases:A NSTEMI patients,CAG showed left anterior descending endometrial imbalance,but CMR test results suggest:left ventricular anterior wall slightly thinner,central-basal left anterior wall,anterior wall of the subendocardial Shaped perfusion defect.Although the improvement of the relevant etiology of examination,AMI etiology is still not clear.