September 4th, 2013
New Dual Biomarker Test Could Speed Rule-Out of MI in the ED
Only 1 in 10 patients with acute chest pain in the emergency department turn out to have an acute myocardial infarction, yet many are not released from the hospital until after 6 to 12 hours of cardiac monitoring and multiple ECG and troponin tests. The search for a test that can rule out MI early in the process has proved elusive.
The Biomarkers in Cardiology-8 (BIC-8) trial, presented at the European Society of Cardiology meeting in Amsterdam, was designed to determine the utility of the combination of troponin and copeptin testing. Copeptin is a marker of severe hemodynamic stress. After an acute MI, copeptin levels increase rapidly. In earlier observational studies, the combination test was found to have a negative predictive value of 99%.
Some 902 patients with suspected ACS who were troponin-negative were randomized to standard treatment or an experimental strategy in which those with a negative copeptin test were discharged early. At 30 days, there were no significant differences in the rate of major adverse cardiovascular events (MACE) between the two groups:
- 5.5% in the standard-care group versus 5.46% in the copeptin group. The results fell within the predefined margin of noninferiority.
- Early discharge occurred much more frequently in the copeptin group: 66% versus 12% with standard care (p<0.001).
Twelve physicians treating patients in the copeptin group overruled a negative copeptin test. In a per protocol analysis, the MACE rate was 5.68% in the standard-care group versus 3.18% in the copeptin group.
Lead investigator Martin Möckel said that “patients with a negative troponin and a negative copeptin result at admission can safely be discharged if the final clinical assessment is consistent with this decision, as long as a timely diagnostic work-up is done in the outpatient setting.” However, he said that a negative copeptin test does not mean that physicians should not take into account the clinical assessment of their patients. “If his or her final clinical assessment excludes discharge due to high suspicion of ACS, perhaps due to recurrent symptoms or an updated history, the patient should not be discharged despite negative biomarker results.”
He said the new process was safe and effective and “has the potential to change clinical practice with high patient safety.”
The study received financial support from Thermo Fisher, which has a copeptin test available in Europe.