Ventricular natriuretic B-type peptide (BNP) after pediatric heart transplantation / Avaliação do peptídeo natriurético tipo B (BNP) após transplante cardíaco pediátrico

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

INTRODUCTION: The rejection is one of the main causes of mortality after pediatric heart transplant. B natriuretic peptide has been used as a diagnostic method for rejection mainly in adult patients after heart transplantation. OBJECTIVE: To correlate BNP levels collected at the moment of endomyocardial biopsy with rejection, to evaluate BNP as an additional method for coronary artery disease and to compare clinical, echocardiograph assessment and hemodynamic parameters with endomyocardial biopsy findings. METHODS: There were 50 BNP blood samples from 33 children submitted to orthotopic cardiac transplantation. Analyzed parameters included: age, gender, race, blood type, reactive panel, functional class, immunosuppressive regimens, number of rejection episodes, echocardiography findings and hemodynamic parameters. The patients were divided in two groups: with rejection and without rejection. RESULTS: Thirty three children with a median age of 10.3 years (54% female) were studied at median time of 4.2 years after heart transplantation. Endomyocardial biopsy diagnosed nine rejection episodes (27%): three were grade 3A; five were grade 2 and one was humoral rejection. At the moment of biopsy most patients were asymptomatic. Average BNP level was 77.2 pg/ml (144.2 pg/ml in the patients with rejection and 65.8 pg/ml in the group without rejection, p=0.02). BNP level was increased in humoral rejection and in patients with coronary artery disease. ROC curve demonstrates BNP levels over 38 pg/ml to present 100% sensibility and 56% specificity to detect acute rejection. The levels of BNP were higher than 100 pg/ml in most of the patients with coronary artery disease (median of 167.5 pg/ml compared with a 40.5 pg/ml in patients without coronary artery disease). The curve ROC shows a critical cut off value for the diagnosis of coronary artery disease at the level of 90 pg/ml in, with p = 0.01. The hemodynamic parameters did not show significant differences between the patients with rejection and the group without rejection. The echocardiogram presented 44% sensibility and a 17 90% specificity to detect the rejection episode (p = 0.02). CONCLUSIONS: Children could be asymptomatic at allograft rejection episodes. BNP level was significantly elevated in children with the allograft rejection episode and may add a valuable information for the rejection assessment. Also, the higher BNP levels associated with coronary artery disease may contribute for its surveillance. Although the echocardiography presented low sensibility to screen for acute rejection episodes, its high specificity enhances its role to structural and functional alterations. The hemodynamic parameters did not contribute for the diagnosis nor presented correlation with the biopsy findings.

ASSUNTO(S)

transplante de coração brain natriuretic peptide graft rejection peptídeo natriurético encefálico biópsia criança biopsy heart transplantation rejeição de enxerto child

ACESSO AO ARTIGO

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