Copeptin helps in the early detection of patients with acute myocardial infarction: primary results of the CHOPIN trial (Copeptin Helps in the early detection Of Patients with acute myocardial INfarction).

OBJECTIVES: The goal of this study was to demonstrate that copeptin levels <14 pmol/L allow ruling out acute myocardial infarction (AMI) when used in combination with cardiac troponin I (cTnI) <99 th percentile and a nondiagnostic electrocardiogram at the time of presentation to the emergency department (ED).

BACKGROUND: Copeptin is secreted from the pituitary early in the course of AMI.

METHODS: This was a 16-site study in 1,967 patients with chest pain presenting to an ED within 6 hours of pain onset. Baseline demographic characteristics and clinical data were collected prospectively. Copeptin levels and a contemporary sensitive cTnI (99 th percentile 40 ng/l; 10% coefficient of variation 0.03 μg/l) were measured in a core laboratory. Patients were followed up for 180 days. The primary outcome was diagnosis of AMI. Final diagnoses were adjudicated by 2 independent cardiologists blinded to copeptin results.

RESULTS: AMI was the final diagnosis in 156 patients (7.9%). A negative copeptin and cTnI at baseline ruled out AMI for 58% of patients, with a negative predictive value of 99.2% (95% confidence interval: 98.5 to 99.6). AMIs not detected by the initial cTnI alone were picked up with copeptin >14 pmol/l in 23 (72%) of 32 patients. Non-ST-segment elevation myocardial infarctions undetected by cTnI at 0 h were detected with copeptin >14 pmol/l in 10 (53%) of 19 patients. Projected average time-to-decision could be reduced by 43% (from 3.0 h to 1.8 h) by the early rule out of 58% of patients. Both abnormal copeptin and cTnI were predictors of death at 180 days (p < 0.0001 for both; c index 0.784 and 0.800, respectively). Both were independent of age and each other and provided additional predictive value (all p < 0.0001).

CONCLUSIONS: Adding copeptin to cTnI allowed safe rule out of AMI with a negative predictive value >99% in patients presenting with suspected acute coronary syndromes. This combination has the potential to rule out AMI in 58% of patients without serial blood draws.