Incremental Value of Objective Cardiac Testing in Addition to Physician Impression and Serial Contemporary Troponin Measurements in Women

Objectives: Guidelines recommend that patients presenting to the emergency department (ED) with chest pain who are at low risk for acute coronary syndrome (ACS) receive an objective cardiac evaluation with a stress test or coronary imaging. It is uncertain whether all women derive benefit from this process. The study aim was to determine the incremental value of objective cardiac testing after serial cardiac markers and physician risk assessment. Methods Women enrolled in the 18-site Myeloperoxidase in the Diagnosis of Acute Coronary Syndrome (MIDAS) study had serial troponinI measured at time 0 and 90minutes and physician risk assessment for the presence of ACS. Risk estimates obtained at the time of ED evaluation were dichotomized as high or nonhigh risk. The primary outcome was the composite of acute myocardial infarction (AMI) or revascularization at 30days. Logistic regression with receiver operator characteristic (ROC) curves and net reclassification index were used to determine the diagnostic accuracy for the composite outcome of 30-day MI or revascularization for two models: 1) troponinI results and physician risk assessment alone and 2) troponinI results, physician risk assessment, and objective cardiac testing. Results A total of 460 women with a median age 58years (interquartile range [IQR]=48.5 to 68years) were included, and 32 (6.9%) experienced AMI or revascularization by 30days. Comparison of the area under the ROC curves (AUC) showed that the addition of objective cardiac testing to the combination of troponinI results and physician risk assessment did not significantly improve prediction of 30-day AMI or revascularization (AUC=0.85 vs. 0.89; p=0.053). Using a threshold of 1%, net reclassification index showed that the addition of objective cardiac testing to troponinI results and physician risk assessment worsened the prediction for 30-day AMI and revascularization. All of the reclassified patients were false positives, with nine (2.1%) patients incorrectly reclassified from <1% risk to 1% risk of 30-day AMI or revascularization. Conclusions In the era of contemporary troponin assays, objective cardiac testing after an ED clinician risk assessment of nonhigh risk and negative troponinI results at 0 and 90minutes does not improve the prediction of 30-day AMI or revascularization in women presenting with chest pain or other symptoms of cardiac ischemia. ACADEMIC EMERGENCY MEDICINE 2013; 20:265-270 (C) 2013 by the Society for Academic Emergency Medicine