Comparison of a cardiac mapping device with standard 12-Lead ECG in the diagnosis of acute coronary syndrome

Abstract

Study objectives: We compare the diagnostic efficacy of an ECG cardiac mapping device (MAP) to a standard 12-lead ECG. Methods: Ninety adult patients being evaluated for acute coronary syndrome (ACS) by cardiac markers and ECG were identified and enrolled. An initial ECG on emergency department (ED) admission and a MAP were obtained simultaneously for study purposes. Physicians were provided the 12-lead ECG and asked to estimate the probability the patient had AMI on an 11-point Likert scale. They were then provided the MAP and asked the same question. In addition, physicians indicated whether the MAP provided additional information and whether it would assist in patient treatment. Patients were followed up inhospital for objective evidence of ACS (positive cardiac markers, positive invasive or noninvasive tests, percutaneous coronary intervention [PCI], or coronary artery bypass graft surgery [CABG]) and at 30 days for adverse outcomes (repeated visit to the ED with ischemic symptoms, CABG, PCI, or death). Receiver operating characteristic (ROC) curves were used to compare the diagnostic efficacy of the MAP to the ECG. Results: Mean age was 51.3 years (SD 10.7 years); 42 (46.7%) patients were white, and 34 (37.8%) were women. Nineteen patients (21.1%) had objective evidence of ACS, and 19 (21.1%) patients had an adverse outcome; 2 patients had an adverse outcome and objective evidence of ACS. The area under the ROC curve for the detection of ACS by the ECG was 0.69 (95% confidence interval [CI] 0.55 to 0.82) and by the MAP was 0.74 (95% CI 0.62 to 0.86). Using a criterion standard of positive troponin, the sensitivity and specificity of the ECG compared with the MAP were 20.0% and 40.0% and 91.8% and 92.9%, respectively. In 51 (56.7%) cases, physicians said the MAP provided additional information, and in 53 (58.9%) cases, physicians said the MAP would assist in treating the patient. In 43 of these, the MAP resulted in an increase (N=11) or a decrease (N=32) in the likelihood of AMI. Conclusion: The MAP improves diagnostic accuracy for ACS compared to the ECG. The MAP also provides physicians with useful information that could assist in the treatment of ACS.