Diagnosis and management of potential acute myocardial infarction (AMI) patients presenting to the hospital emergency department (ED) with chest pain are difficult. To aid in clinical decision making, a multivariate logistic regression model was developed using the patient’s presenting history, electrocardiogram (ECG), and biochemical marker (cardiac Troponin T, cTnT) to predict the probability of AMI. Data from 102 AMI and 619 non-AMI patients from a multicenter clinical trial were used for model building. The World Health Organization criteria were used for AMI diagnosis. Univariate analyses were performed to assess the effect of individual factors. Based on the significance of univariate effect and clinical importance, the following variables were included in a risk factor only model: age, sex, chest pain, systolic blood pressure, smoking, and history of myocardial infarction and hypertension with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.66 (95% confidence interval [CI]: 0.60-0.71) and an R2 of 0.09. The final model, which included the risk factors and results of ECG and cTnT, increased the AUC and R2 values to 0.93 (95% CI: 0.90-0.96) and 0.83, respectively. At the probability level of 0.10 for AMI, the model showed a sensitivity of 78.4% and a specificity of 92.6%. Statistical modeling is a useful tool in predicting risk of chest pain patients in the ED.

Objective: To evaluate the performance of a new bedside whole-blood rapid assay for cardiac troponin T (cTnT) in patients presenting to the ED with symptoms consistent with acute coronary ischemia,Methods: A prospective, observational trial was performed in 8 participating medical centers. Serial blood samples were obtained on presentation to the ED and 3 and 6 hours later. The cTnT whole-blood rapid assays were performed immediately at the site. Treating physicians and patients were blinded to the results of the rapid assays. Serum samples were analyzed at the core laboratory for serum cTnT, creatine kinase (CK)-MB, and myoglobin. The sensitivity of the rapid assay for detecting acute myocardial infarction (AMI) was compared with the sensitivities of serum cTnT, CK-MB, and myoglobin assays.Results: Of 721 patients, 102 were diagnosed as having AMI. The median elapsed time from symptom onset to ED arrival was 3 hours. The sensitivities of the rapid assay for detecting AMI were 19.6%, 59.0%, and 69.7% at 0, 3, and 6 hours, respectively. The sensitivities of the serum cTnT assay (p-values for comparison with the rapid assay for cTnT) were 25.0% (p = 0.18), 69.6% (p = 0.04), and 79.8% (p = 0.02) at 0, 3, anti 6 hours, respectively. The CK-MB and myoglobin sensitivities were 21.9%, 64.5%, and 81.0%; and 43.8%, 77.4%, and 71.4%, respectively. There were 7 patients with AMI who had negative rapid assay readings and positive serum cTnT levels; 4 of these patients were enrolled at the same site. Twenty patients not diagnosed as having AMI had at least one positive rapid assay. Fourteen of these 20 patients had a diagnosis of clinically relevant cardiac disease.Conclusions: The sensitivity of this whole-blood rapid cTnT assay for detecting AMI is comparable to that of current serum assays and offers the advantage of providing rapid bedside results. Discrepancies between serum and whole-blood assays for cTnT noted in this study may indicate the need for further education for the test reader prior to patient use.