The Value Of Troponin And ECG On Admission In Fast Evaluation In Patients With Symptoms Suggestive Of Acute Coronary Syndrome

Background and objectivesAcute chest pain is one of the most common acute and critical diseases to emergency departments(EDs).Acute coronary syndrome(ACS)is an important reason for acute chest pain.However,ACS is eventually excluded in most patients with chest pain after further examination,which costs a lot of medical resources.Therefore,it is of great significance to evaluate symptoms suggestive of ACS rapidly and exclude low-risk chest pain at an early stage.At present,patients with symptoms suggestive of ACS undergo regular electrocardiogram(ECG)and cardiac troponin(cTn)inspection method.There are a plenty of researches on the role of sensitive cardiac troponin(s-cTn)in the early diagnosis of acute myocardial infarction at home and abroad,while few on the role of ECG in fast evaluation in patients with symptoms suggestive of ACS and the value of Troponin on admission and ECG in fast evaluation in patients with symptoms suggestive of ACS.Therefore,we conducted this study.MethodsThis study is a prospective observational study.According to the inclusion and exclusion criteria established,1651 patients with symptoms suggestive of ACS admitted to the emergency department of Qilu Hospital of Shandong University and Affiliated Hospital of Jining Medical University were consecutively enrolled from January 2016 to October 2017.We collected the general clinical information of the patients,including the sex,age,heart rate,blood pressure,initial ECG and the number,unit,type,99th upper limit(99th URL)and limit of detection(LOD)of sensitivity cardiac troponin I(s-cTnI)on admission.We recorded risk factors of ACS,including diabetes,hypertension,hyperlipidemia,smoking history and family history of early coronary heart disease.We recorded the situation of their cardiovascular medical history such as myocardial infarction,peripheral artery disease and cerebral apoplexy.The patients were diagnosed by at least two cardiologists who combined s-cTnI,ECG and other clinical data.According to the diagnostic results,enrolled patients were divided into AMI group and non-AMI group.Five different combinations of detection methods were used to analyze all the subjects:i)s-cTnI(99th URL):the cut-off was 0.03ng/ml at the 99th upper limit of s-cTnI;?)s-cTnI(LOD):the cut-off was 0.008ng/ml at the limit of detection of s-cTnI;?)ECG;?)s-cTnI(99th URL)H+ECG;?)s-cTnI(LOD)+ ECG.Compared the above general clinical information and sensitivity,specificity,positive predictive value(PPV),negative predictive value(NPV)and the 95%confidence interval(95%CI)of different combinations of detection methods using the SPSS 25.0 software.The descriptive results are presented as the median(25th,75th percentile),mean ± SD for continuous variables and frequency and percentage for categorical variables.Comparison between groups was made by t-test and u-test for continuous variables appropriately.With regard to categorical variables,?2 test or McNemar exact test was used.Results1.Baseline characteristicsA total of 1651 patients with symptoms suggestive of ACS were collected from January 2016 to October 2017.868(52.6%)were male and 783(47.4%)were female,with an average age of 65(56-74)years.Among them,218(13.2%)were AMI and 1433(86.8%)were not AMI.There was no significance in age,heart rate,systolic blood pressure and diastolic blood pressure between AMI and non-AMI group.The proportion of male in AMI group was higher than non-AMI group(P<0.05).In terms of risk factors,the rates of diabetes,hypertension,hyperlipidemia and smoking in the AMI group were higher than those in the non-AMI group(P<0.05).Furthermore,in terms of cardiovascular medical history,the rate of myocardial infarction in AMI group was higher than that in non-AMI group(P<0.05).However,there was no significance in the history of peripheral artery disease and cerebral apoplexy between the two groups.2.Recurrent myocardial infarction and first myocardial infarctionThe incidence of AMI in patients with previous history of myocardial infarction was higher than those without previous history of myocardial infarction(P<0.05).Among all patients in AMI group,recurrent myocardial infarction accounted for 33.5%.3.Initial s-cTnI and ECGInitial s-cTnI was higher in AMI group than that in non-AMI group(P<0.05).Similarly,the proportion of ECG ischemia in AMI group was higher than that in non-ami group(P<0.05).4.Diagnostic performance of five different algorithms?.s-cTnI(99th URL):The criteria of s-cTnI<0.03ng/ml(rule-out)had a sensitivity of 89.0%,specificity of 66.7%,PPV of 28.9%,and NPV of 97.6%;?.s-cTnI(LOD):The criteria of s-cTnI<0.008ng/ml(rule-out)had a sensitivity of 95.4%,specificity of 53.3%,PPV of 23.7%,and NPV of 98.7%;?.ECG:The criteria of ECG ischemia(rule-out)had a sensitivity of 71.1%,specificity of 60.1%,PPV of 21.3%,and NPV of 93.2%;?.s-cTnI(99th URL)+ ECG:the combination of s-cTnI<0.03ng/ml and ECG ischemia(rule-out)had a sensitivity of 96.8%,specificity of 45.4%,PPV of 21.2%,and NPV of 98.9%;?.s-cTnI(LOD)+ ECG:the combination of s-cTnI<0.008ng/ml and ECG ischemia(rule-out)had a sensitivity of 97.7%,specificity of 38.8%,PPV of 19.5%,and NPV of 99.1%.(Compare with every other group,P<0.05,respectively)ConclusionsThe combination of s-cTnI and ECG on admission improves sensitivity and NPV in early diagnosis of suggestive ACS.This study provides more evidence for fast evaluation and early rule-out low-risk chest pain in patients with symptoms suggestive of acute coronary syndrome.