Abstract 18150: Incremental Value of Objective Cardiac Testing in Addition to Physician Impression and Serial Contemporary Troponin Measurements in Women

Abstract

Background: Guidelines recommend that patients presenting to the emergency department (ED) with chest pain who are at low risk for acute coronary syndrome (ACS) undergo objective cardiac testing. It is uncertain whether women derive benefit from this process. Hypothesis: We hypothesized that objective cardiac testing after serial contemporary troponin measurements and physician risk assessment provides incremental value to women.

Methods: We included women enrolled in the 18-site Myeloperoxidase in the Diagnosis of Acute Coronary Syndrome (MIDAS) study who had serial troponin I measured using a contemporary assay at time 0 and 90 minutes. Physician risk estimates for ACS were obtained at the time of ED evaluation and dichotomized as high or non-high risk. The primary outcome was the composite of acute myocardial infarction (AMI) or revascularization at 30 days. Logistic regression with receiver operator characteristic curves and net reclassification index were used to determine the diagnostic accuracy for the composite outcome for two models: (a) troponin I results and physician risk assessment alone and (b) troponin I results, physician risk assessment, and objective cardiac testing.

Results: 461 women with a median age 58 (IQR 48.5, 68) were included, and 32 (6.9%) experienced AMI or revascularization at 30 days. Comparison of receiver operator characteristics (ROC) curves showed that the addition of objective cardiac testing to troponin I results and physician risk assessment did not significantly improve prediction of 30-day AMI or revascularization (AUC 0.85 vs 0.89; p=0.06) . Using a threshold of 1%, net reclassification index showed that the addition of objective cardiac testing to troponin I results and physician risk assessment worsened the prediction for 30-day AMI and revascularization. All of the reclassified patients were false positives, with 10 (2.3%) patients incorrectly reclassified from <1% risk to ≥1% risk of 30-day AMI or revascularization

Conclusion: Objective cardiac testing after a clinician risk assessment of non-high risk and negative troponin I results at 0 and 90 minutes does not improve the prediction of 30-day AMI or revascularization in women presenting to the ED with chest pain or other symptoms of cardiac ischemia.