Differential Regulation of Plasma Copeptin Levels in Patients with Heart Failure: A Single-Center Prospective Study

Elevated levels of arginine vasopressin (AVP) have been reported to be involved in the pathogenesis of heart failure (HF). Recent evidence has shown the role of copeptin, the C-terminal fragment of pro-AVP, as a biomarker in patients with HF. However, the relevant information is still limited. Therefore, we evaluated 39 Japanese patients admitted for HF between 2013 and 2015 (23 males and 16 females with an average age of 79.2 years). They were treated according to the Japanese acute HF guideline. Plasma copeptin levels were measured on admission and about 1 week later. The median plasma copeptin levels on admission were 0.5 (0.1-50.6) pmol/L, higher than the normal values (0.24 ± 0.06 pmol/L). Despite the similar clinical severity on admission, the patients showed great variability in plasma copeptin levels. They were divided into three groups (13 patients/group) according to plasma copeptin levels on admission: highest (> 30.8 pmol/L), midrange, and lowest (< 0.2 pmol/L) groups. Initial treatment improved HF symptoms in 37 of 39 patients, with the two unresponsive patients in the lowest group. Notably, plasma copeptin responses to initial treatment were different, depending on admission copeptin levels. The initial treatment significantly decreased copeptin levels in the highest group, but increased copeptin levels in the lowest group. By contrast, patients in the midrange group showed no significant changes. Thus, the treatment appears to restore the plasma copeptin levels. In conclusion, HF is a complex syndrome with the differential integration of stimulatory and inhibitory inputs to the AVP/copeptin secretory system.