Six-hour versus 12-hour protocols for AMI: CK-MB in conjunction with myoglobin

Clinical role of serum Copeptin in acute coronary syndrome

Objective

To assess the role of Copeptin in diagnosis of acute myocardial infarction in troponin-blind period.

Subjects and methods

This study was conducted on 40 patients who presented to emergency department complaining of chest pain and were highly suspicious to have acute cardiac ischemia, in addition to 10 subjects serving as a healthy control group. Blood samples were collected for determination of CK-MB, cTnI and Copeptin. These were measured twice (in patients’ group); at 3 h and then at 6–9 h from admission time.

Results

The first sample revealed a non-significant difference between UA group and AMI group as regards CKMB and troponin, however, high significant difference was found as regards Copeptin (Z = 5.29, P < 0.001). Moreover, ROC curve analysis of serum Copeptin for discriminating AMI group from UA group in the first sample showed diagnostic sensitivity and specificity of 100%.

In conclusion

Determination of copeptin in early diagnosis of AMI has diagnostic value being superior to a conventional cTn-I within the first three hours after acute chest pain.

Diagnosis of myocardial injury by biochemical markers: problems and promises

The role of biochemical markers in the diagnosis of acute coronary syndromes has increased considerably in the past decade. The World Health Organization previously defined acute myocardial infarction as a combination of at least 2 of 3 components: symptoms consistent with acute myocardial infarction, electrocardiogram changes diagnostic of acute myocardial infarction, and an enzyme pattern with classic rise and fall. Measurement of creatine kinase and its MB fraction by various assays was the gold standard for the diagnosis. Troponins are more specific and sensitive markers for myocardial injury, and their increasing utilization has resulted in a broadening of the definition of acute myocardial infarction to incorporate high-risk acute coronary syndromes. Previously, traditional enzyme evaluation left patients with small amounts of cellular death undiagnosed; these patients were categorized as having unstable angina or, worse, noncardiac chest pain. Newer markers now identify these patients as a subgroup at high risk for cardiac death or cardiac events. Newer therapeutic interventions and a more invasive strategy have been shown to improve outcomes in this high-risk subgroup. Increased specificity has also reduced the number of patients who undergo extensive, expensive, and invasive evaluations for noncardiac syndromes due to false elevations of traditional markers. This article comprehensively reviews the evolution of biochemical markers for the diagnosis of acute myocardial infarction, addressing their promise for improving delivery of care and outcomes and their technical and diagnostic pitfalls.