Investigation of the Biomarker Copeptin in Patients With Acute Myocardial Infarction

In patients with symptoms suggestive of acute coronary syndrome (ACS) such as chest pain or
pressure, shortness of breath, diaphoresis, and nausea, detection of a rise and/or fall of
troponin with at least one value above the 99th percentile of the upper reference limit is
essential to the diagnosis of acute myocardial infarction (AMI). However, current troponin
testing has limitations, including antibody specificity, assay imprecision, lack of
standardization and a relatively late increase in the circulating troponin level after the
onset of ischemia. Studies have shown a low diagnostic sensitivity of troponins when
measured early (<6 hours) after symptom onset. Although there are some more sensitive
troponin assays with a coefficient of variation (CV)10% at the 99th percentile of a normal
reference population, most troponin assays have an imprecision CV of around 20% at the 99th
percentile of the reference population. The early insensitivity of troponin results in an
unmet need in the clinical evaluation of patients presenting with suspected ACS and AMI.

Copeptin may improve early AMI diagnostic sensitivity because of a number of unique
characteristics.

- Copeptin levels are elevated at presentation in patients with AMI compared to patients
with other presentations.

- Copeptin levels are elevated in patients with AMI even when troponin levels were not
elevated at the time of initial presentation.

- Thus, a combination of troponin and copeptin levels at presentation may result in a
more accurate diagnosis of acute AMI than troponin alone.

- Copeptin levels drop 1 day after an AMI.