The Co(II)-albumin binding assay accurately detected myocardial ischemia with an area under the ROC curve of 0.95 (95% CI, 0.92-0.99), yielding 88% sensitivity and 94% specificity at a 0.50 ABSU cutoff.
Observational (n=167)
Double-blind
No
Does the Co(II)-albumin binding assay accurately detect myocardial ischemia in emergency department patients?
The Co(II)-albumin binding assay is highly sensitive and specific for detecting myocardial ischemia but performs poorly in distinguishing between ischemia with and without myocardial infarction.
Effect estimate: AUC 0.95 (95% CI 0.92-0.99)
p-value: p=<0.0001
BACKGROUND: Clinical diagnoses were correlated with results of a Co(II)-albumin binding assay in 167 patients treated at an emergency department of a health maintenance organization. METHODS: Patients were evaluated as being nonischemic or potentially ischemic through standard coronary disease indicators creatine kinase (CK), CK-MB, cardiac troponin I, and electrocardiographic findings and were tested by a Co(II)-albumin binding assay. Samples were tested anonymously, and the study was double-blinded. The sensitivity and specificity of this assay for the detection of ischemia were evaluated by ROC curve analysis. Known Co(II) binding sites on albumin were analyzed by N-terminal amino acid sequencing. RESULTS: The mean absorbance units (ABSU) +/- 2 SD for non-myocardial ischemic and myocardial ischemic individuals measured at 470 nm were 0.43 +/- 0.10 and 0.63 +/- 0.25, respectively (P or =0.70) individuals and one nonischemic individual tested. However, only one individual with a high ABSU (0.80) had two missing amino acid residues (DA) from the N-terminal region. Clinical diagnosis for this patient did not reveal an ischemic event. CONCLUSIONS: The Co(II)-albumin binding test may serve as a useful diagnostic tool in emergency facilities for the assessment of myocardial ischemia. High and low ABSU were associated with myocardial ischemic individuals and non-myocardial ischemic individuals, respectively. However, the Co(II)-albumin binding was a poor discriminator between ischemic individuals with and without MI.
Bhagavan et al. (2003) conducted an observational in Myocardial ischemia (n=167). Co(II)-albumin binding assay vs. Standard coronary disease indicators (nonischemic vs potentially ischemic) was evaluated on Detection of myocardial ischemia (AUC 0.95, 95% CI 0.92-0.99, p=<0.0001). The Co(II)-albumin binding assay accurately detected myocardial ischemia with an area under the ROC curve of 0.95 (95% CI, 0.92-0.99), yielding 88% sensitivity and 94% specificity at a 0.50 ABSU cutoff.