Copeptin in Relation to New York Heart Association Class in Heart Transplant Recipients and Kidney Transplant Recipients

Copeptin is cosynthesized with vasopressin, also known as antidiuretic hormone. It is more stable than vasopressin. Recently copeptin has been studied as a diagnostic and prognostic marker for various diseases. Among patients with destabilized heart failure, copeptin was an accurate prognostic marker for mortality. Chronic heart failure is present in more than one-third of incident dialysis patients as well as in kidney allograft recipients. The aim of this study was to assess copeptin in orthotopic heart and kidney allograft recipients in relation to New York Heart Association (NYHA) class and kidney function. The studies were performed on 134 prevalent patients including 103 males and 31 females after orthotopic heart (OHT) and 80 prevalent kidney allograft recipients including 51 males and 29 females. Glomerular filtration rate (GFR) was estimated using the simplified MDRD and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulae. We measured complete blood count, urea, serum lipids, fasting glucose, creatinine, NT-proBNP using standard methods in the central laboratory of the hospital. Plasma copeptin, estimated using a commercially available kit, was correlated with kidney function parameters of creatinine, estimated GFR by MDRD and CKD-EPI, NT-proBNP and ejection fraction. Copeptin was significantly lower among kidney allograft than orthotopic heart recipients: 0.71 ± 0.13 ng/mL versus 0.99 ± 0.36 ng/mL (P < .001). Kidney allograft recipients were significantly younger, with shorter times after transplantation, but similar serum creatinine and estimated GFR values. Kidney allograft recipients displayed lower NYHA classes. Copeptin was higher in chronic kidney disease stage 4 than stage 2; similarly in NYHA class III versus I. However, these correlations did not achieve statistical significance. There was no effect of gender, diabetes, or hypertension on copeptin levels in either group of transplanted patients. Among the heart transplant population copeptin is independently associated with kidney and heart function, but not in kidney allograft recipients. It may also predict outcomes of orthotopic heart transplant patients.