Abstract
Ischemia modified-albumin (IMA®) is a useful early cardiac biomarker for the diagnosis of acute coronary syndrome. In this study the diagnostic efficiency and the cost effectiveness of the oxidative stress biomarker (ischemia modified-albumin), myocardial necrosis (high sensitivity cardiac troponin, heart fatty-acid binding protein), vascular stress (copeptin) and myocardial dysfunction and hemodynamic stress (B-type natriuretic peptide) were evaluated for the diagnosis of acute myocardial infarction and cost benefit in low risk patients presenting to the emergency department with chest pain.This study was a retrospective observational study of a prospective randomised controlled trial. A surplus of well characterised blood samples were analysed for the above biomarkers. A meta-analysis study of the diagnostic performance of Ischemia modified-albumin assay in patients presenting with chest pain suggestive of acute coronary syndrome was conducted. The-cost-benefit analysis was based on doctor on demand scenario.
Four hundred and forty-four samples were made available for this study, of which 174 patients had samples taken on admission and at 90 min. Three patients had a final diagnosis of acute myocardial infarction and one patient died. The difference in ischemia modified-albumin concentration was statistically significant (p = 0.002) between patients presenting on admission and at 90 min after admission. NT-pro-BNP had the highest diagnostic efficiency on admission with an area under the receiver operator curve (AUC) of 93% (95% CI, 82-93%). IMA did not reach the desired diagnostic efficiency with an AUC ranging from 54%-58%. The combined diagnostic efficiency of IMA plus high sensitivity cardiac troponin had a sensitivity and specificity of 71% (95% CI, 56-82%) and 100% (95% CI, 98-100%) respectively. The remaining biomarkers were not diagnostically efficient when combined with IMA. All biomarkers demonstrated poor prognostic value in predicating major adverse cardiac events within 30 days. Meta-analysis (n = 4295) demonstrated a sensitivity of 77.73% (95% CI, 72.21-83.24%) and specificity of 72.71% (95% CI, 64.09-81.34%) respectively. The negative predictive value and positive predictive was 80.13% (95% CI, 73.18-87.08%) and 67.91% (95% CI, 58.47-77.39%) respectively. The implementation of high sensitivity troponin plus IMA on admission would cost £638.00 per high-risk patient, compared to £464.00 for troponin alone as per current protocol.
In conclusion, IMA plus high sensitivity cardiac troponin is cost effective and could be used to rule-out acute myocardial infarction. High sensitivity cardiac troponin is the most diagnostically efficient biomarker for early diagnosis of acute myocardial infarction. IMA assay alone is not suitable for the diagnosis of acute myocardial infarction.
| Date of Award | Jun 2016 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | Graham Mills (Supervisor) & Gavin Knight (Supervisor) |