Key result
Ischaemia modified albumin (IMA) testing failed to accurately diagnose raised 12-hour troponin levels or acute coronary syndrome, yielding poor area under the curve values of 0.52 and 0.53.
Why the study?
Does ischaemia modified albumin (IMA) measurement accurately exclude acute coronary syndrome in patients presenting to the emergency department with suggestive symptoms?
Observational (n=248)
No
Does ischaemia modified albumin (IMA) measurement accurately exclude acute coronary syndrome in patients presenting to the emergency department with suggestive symptoms?
Effect estimate: AUC 0.52 and 0.53
Ischaemia modified albumin (IMA) has poor diagnostic accuracy and cannot be used as an early negative predictor to rapidly exclude acute coronary syndrome in the emergency department.
Should not guide ACS exclusion in the ED; leaves open whether alternative biomarkers warrant prospective validation.
OBJECTIVE: To evaluate ischaemia modified albumin (IMA) as an early negative predictor of acute coronary syndrome (ACS) in different time to presentation groups and different cardiac risk groups. METHODS: A prospective observational study was performed in the emergency department at Royal Perth Hospital. Consecutive patients with symptoms suggestive of ACS needing delayed troponin measurements were recruited. All enrolled patients had both IMA and troponin measurements performed on their initial blood samples. The time of the initial blood tests and thrombolysis in myocardial ischaemia (TIMI) risk scores were recorded. Initial IMA results were compared with 12 h troponin levels and a discharge diagnosis of ACS. More detailed analyses were made according to different times to presentation (0-4 h, 5-12 h) and cardiac risk (TIMI score 0-1, 2-7). Sensitivity, specificity, positive predictive value, negative predictive value and likelihood ratio were calculated. Receiver operating characteristic (ROC) curves were plotted to determine the best diagnostic cut-off for IMA. RESULTS: 248 patients were enrolled (151 (61%) men, mean age 65 years). All 248 patients had 'positive' IMA results using the 85 U/ml cut-off value recommended by the manufacturer. ROC curves failed to show improved cut-off points for diagnosing raised 12 h troponin levels or ACS; the area under the curve (AUC) was 0.52 and 0.53, respectively. ROC curves produced similar poor results in all subgroups. In the subgroup with time to presentation 0-4 h and TIMI score 0-1 for diagnosing ACS, the AUC was slightly better at 0.58. CONCLUSION: This study does not support the use of IMA as a negative predictor for ACS.
No takes yet. Share an insight, caveat, or question.
Lin et al. (2010) conducted an observational in Acute coronary syndrome (n=248). Ischaemia modified albumin (IMA) was evaluated on Diagnosing raised 12 h troponin levels or ACS (AUC 0.52 and 0.53). Ischaemia modified albumin (IMA) testing failed to accurately diagnose raised 12-hour troponin levels or acute coronary syndrome, yielding poor area under the curve values of 0.52 and 0.53.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: