Use of copeptin in the detection of myocardial ischemia

Abstract

Background The role of the arginine–vasopressin (AVP) system in the response to myocardial ischemia is unclear. Copeptin, the C-terminal part of the AVP prohormone is secreted stoichiometrically with AVP. Methods A total of 253 consecutive patients with suspected myocardial ischemia referred for rest/ergometry myocardial perfusion single-photon emission computed tomography (SPECT) were enrolled. We evaluated the response of copeptin during exercise and determined whether measurement of copeptin may be helpful in the detection of myocardial ischemia. Results Myocardial ischemia on perfusion images was detected in 127 patients (50%). Median copeptin levels increased significantly with exercise in patients with ischemia as well as in patients without ischemia (from 3.8 [IQR 2.8–6.6] to 12.3 [IQR 5.2–39.6] pmol/l, P < 0.001; and from 3.6 [IQR 2.6–5.7] to 10.8 [IQR 5.0–24.5] pmol/l, P < 0.001). Median exercise-induced changes in copeptin (Δcopeptin) were similar in both groups (7.7 versus 5.1 pmol/l, P = 0.150). The area under the ROC curve for the ability of Δcopeptin to detect myocardial ischemia was 0.552. Conclusions Copeptin levels increased threefold with exercise, irrespective of the presence or absence of myocardial ischemia. Therefore, myocardial ischemia does not seem to be a major trigger of the AVP system. Measurement of copeptin does not seem helpful in the detection of exercise-induced myocardial ischemia.