N-terminal pro-brain natriuretic peptide as a potential non-invasive marker of cardiac transplantation rejection

Transplantation is the main palliative treatment for patients with heart failure. Clinical signs of cardiac rejection can be very non-specific or even absent. Thus, successful management relies on early diagnosis, ideally before the onset of clinical features of cardiac dysfunction. Although endomyocardial biopsy (EMB) is the reference diagnostic method, several non-invasive methods have been proposed to reduce the number of EMB performed during the follow-up of the transplanted patient. The aim of the present work was to study the potential relationship between rejection and serum concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) as well as cardiac troponin T (cTnT) in post-transplantation patients.

Twenty-three consecutive orthotopic heart transplantation recipients with a mean age of 51 years (range 22-66) were prospectively recruited from the cardiac transplantation programme at the Hospital Universitario Central de Asturias. Serum NT-proBNP and cTnT were measured during the follow-up of these patients (ranging from 9-13 months post-transplantation) and compared with the results of EMB.

Serum NT-proBNP concentrations progressively decrease during the first year post-transplantation, reaching concentrations slightly higher than the reference values. NT-proBNP concentrations increase significantly in those patients with a rejection episode graded >or=3A on the basis of the EMB (P<0.001, Mann-Whitney U-test). No relation between cTnT and rejection was observed.

The potential of NT-proBNP as a non-invasive marker of transplantation rejection shows promising results, since NT-proBNP concentrations increase whenever a significant rejection event takes place in the first year of follow-up.