Risk Stratification Of Acute Coronary Syndrome During 1-Year Follow Up And A Research Of Diagnostic Model For STEMI

BackgroundAcute coronary syndrome(ACS)has a high mortality and a large population base.ACS is composed of a series of clinical syndromes with different risk stratification and prognosis.Thus,early accurate risk stratification is considered important for the optimal management of ACS.The public risk scores(such as the GRACE score)place emphasis on the clinical conditions of ACS patients.It helps to increase the accuracy of the prognostic judgment when combining biomarkers and left ventricular ejection fraction(LVEF)together with a risk score.Currently,there is still less published data about the stratification of ACS patients containing all these three aspects.In addition,lots of inexperienced paramedics could not identify ST-segment elevation myocardial infarction(STEMI)through electrocardiograms easily.Several studies examined the accuracy of paramedic identification of STEMI and reported false-positive rates(patients incorrectly diagnosed with STEMI by paramedics when no STEMI was present)ranging from 8%to 40%,which caused unnecessary tests and a waste of resource utilization.This study aimed to evaluate the one-year prognosis of ACS and facilitate the diagnosis of STEMI,using a combination of biomarkers,LVEF and clinical data(medical history,vital signs,etc).MethodConsecutive patients(n=1209)diagnosed with ACS undergoing percutaneous coronary intervention in Sir Run Run Shaw hospital were enrolled between April 2015 and February 2016.Patients were evaluated at baseline for clinical characteristics during the hospitalization.Follow-up was performed at 1 year(365 ± 90 days)(phone call or clinical visit)with events adjudicated by prespecified event adjudication forms.The combining endpoint was major adverse cardiac events(MACE,all-cause mortality and myocardial infarction)during 1 year follow-up.891 patients were successfully followed up.According to the diagnosis,patients were divided into 3 groups:unstable angina(UA)group,non-ST-segment elevation myocardial infarction(NSTEMI)group and STEMI group.Their baseline data and the occurrence rates of MACE were compared.Then the UA and NSTEMI group were combined into non-ST-segment elevation ACS(NSTE-ACS)group.The diference between NSTE-ACS group and STEMI group were compared.The independent risk factors of MACE happened within 1 year were assessed using multivariate Logistics regression analysis.Thus a new risk score was concluded and it was tested by the area under the receiver operating characteristic(ROC)curve.Lastly,single factor Logistics regression analysis of STEMI was used to obtain STEMI associated predictors.The independent associated factors of STEMI were assessed by multivariate Logistics regression analysis,and a new diagnostic score was concluded.The sensitivity and specificity of the diagnostic score were verified by ROC curve.ResultsA total of 891 patients were enrolled with 653(73.3%)in the UA group,117(13.1%)in the NSTEMI group and 121(13.6%)in the STEMI group.607(68.1%)had hypertension and 230(25.8%)had diabetes mellitus.During 1-year follow up,19(2.1%)were dead,23(2.6%)had myocardial infarction,42(4.7%)had MACE.Then UA group and NSTEMI group were combined into NSTE-ACS group.The occurrence rate of MACE in the STEMI group was much higher than in the NSTE-ACS group(death 7.4%vs.1.3%,p<0.001;MI 6.7%vs.1.9%,p=0.006;MACE 14.0%vs.3.2%,p<0.001).Using multivariate Logistics regression analysis,the independent risk factors of MACE happened in 1 year were STEMI(OR:5.586,95%CI:1.077-9.900,p=0.036),age(OR:1.048,95%CI:1.006-1.091,p=0.023),diabetes mellitus(OR:2.399,95%CI:1.047-5.496,p=0.039),history of MI(OR:4.370,95%CI:1.701-11.226,p=0.002),DDI>0.5μg/ml(OR:3.401,95%CI:1.339-8.640,p=0.010),LVEF<50%(OR:3.893,95%CI:1.660-9.131,p=0.002).Then a new risk score MACE(OR:2.608,95%CI:2.012-3.380,p<0.001)was established.If the MACE plus 1 score,the risk of having MACE events within 1 year increased by 2.608 times.Then the sensitivity and specificity of the MACE score were evaluated by the area under the ROC curve(AUC).It got a net increase than a single factor,respectively,27.73%,32.76%,44.60%,39.34%,21.12%,28.51%.The sensitivity and specificity of the MACE score were better than any other single factor.In the NSTE-ACS subgroup,the independent risk factors of MACE happened in 1 year were history of MI(OR:4.403,95%CI:1.518-12.776,p=0.006),DDI>0.5μg/ml(OR:2.679,95%CI:1.019-7.044,p=0.046),LVEF<50%(OR:2.972,95%CI:1.031-8.565,p=0.044).Then a new risk score MACE(NSTE-ACS)(OR:2.582,95%CI:1.693-3.939,p =<0.001)was established.Using multivariate logistic regression analysis,the independent associated factors for STEMI were WBC<3.5 or>9.5*109/L(OR:4.774,95%CI:2.607-8.742,p<0.001),NT proBNP>2000pg/mL(OR:2.072,95%CI:1.074-3.995,p=0.030),hsTnI>0.11 ng/ml(OR:9.593,95%CI:5.275-17.445,p<0.001),CKMB>72 IU/L(OR:3.343,95%CI:1.134-9.857,p=0.029)and GFR<90 ml/min*1.73m2(OR:0.341,95%CI:0.187-0.622,p<0.001).Therefore,a new diagnostic score STEMI(OR:2.718;95%CI:2.291-3.225,p<0.001)was established.If the STEMI plus 1 score,the risk of got STEMI increased by 2.718 times.It got a net increase of AUC than a single positive factor,respectively,23.53%,49.23%,41.57%,9.43%.The sensitivity and specificity of the STEMI score were better than any other single factor.ConclusionIn the ACS patients with PCI:(1)During 1-year follow up,the occurrence rate of all-cause death or myocardial infarction between the UA and NSTEMI group was similar.So they can be combined to treat in clinical management.Intensive care should be paid for these patients with history of MI,DDI>0.5 μg/ml or LVEF<50%.(2)The patients with STEMI have a significantly increased risk of death or myocardial infarction within 1-year follow up than the ones with NSTE-ACS.We need to pay more attention to them in the process of clinical treatment and follow-up.(3)The MACE score could be used to predict the prognosis of the patients with ACS.The related factors were STEMI,elderly,diabetes mellitus,history of MI,DDI>0.5 μg/ml or LVEF<50%.Intensive care should be paid for these patients.(4)The STEMI score is useful to help diagnose STEMI.It can reduce false-positive and false-negative rates.It is necessary to consider the diagnosis of STEMI when a patient has one of following situations:WBC<3.5 or>9.5*109/L,NT proBNP>2000 pg/mL,hsTnI>0.11 ng/mL,CKMB>72 IU/L.(5)Further research needs to be conducted to make the risk scores or diagnostic score more practical.