proBNP represents the precursor of the brain natriuretic peptide (BNP) and is released by the cardio-myocytes as a result of the myocardial stretch. It is fractioned into two components, BNP and NT-proBNP. We use more often the determination of NT-proBNP levels in laboratory tests because of its prolonged biological half-time (60-120 minutes, much longer than the BNP half-life).
Aim: To determine a link between the plasmatic levels of NT-proBNP and heart failure syndrome (HFS).
Material and method: We studied 40 patients admitted in the Internal Medicine Clinic of the Western University "Vasile Goldiş" Arad, during a two years period (2004-2005). Every patient had a clinical examination, an echocardiography and the determination of NT-proBNP levels. For the determination of the BNP plasmatic levels we used a special kit Elecsys proBNP, which is now largely available. The NT-proBNP levels were correlated with the HFS diagnosis (the presence of dyspnea and the ejection fraction).
Results: In 29 patients the NT-proBNP levels were above the upper limit of 125 pg/ml, 86% of them being clinically diagnosed with HFS. 11 patients had BNP levels in the normal values range and 4 of them were clinically diagnosed with HFS. Correlating the NT-proBNP plasma levels and NYHA class of HF we could establish some guidelines regarding the critical BNP values upon which the diagnostic of HFS is almost certain. The minimum level of BNP at which a patient was diagnosed with HF was 89.9 pg/ml. Levels above 125 pg/ml predicts o risk six times higher for HFS.
Discussions: The BNP plasma values may be modified in hepatic or renal failure, which can cause false high levels of hormone. These situation should be considered possible error sources of diagnosis if the HFS is evaluated only by the means of NT-proBNP plasma levels.
Conclusions: The dosage of plasma levels of NT-proBNP is useful into patients with suspected HFS, if the other methods of diagnosis are not reliable. There is a link between the NT-proBNP plasma levels and the NYHA HFS class. However only the dosage of BNP is not sufficient for a correct diagnosis of HFS.