Predictor of mitral valve regurgitation severity and left ventricular dilatation using amino-terminal pro-brain natriuretic peptide marker in pediatric rheumatic heart disease.

Abstract

Background: Early rheumatic heart disease (RHD) is characterized by valve regurgitation, leading to ventricular distention and possible elaboration of amino-terminal pro-brain natriuretic peptide (NT-proBNP).

Methods: Thirty-one children with RHD were entered in the study. Transthoracic echocardiography was performed in all patients to assess the severity of the valve disease and cardiac function, thus will be classified into three groups: mild, moderate, and severe mitral valve regurgitation (MR), with and without left ventricular (LV) dilatation. At the time of echo, venous blood samples were drawn; thus, NT-proBNP levels were measured using sandwich immunoassay.

Results: The median NT-proBNP levels in mild, moderate, and severe MR were 32.34, 120.75, and 7094 pg/ml, respectively. The median NT-proBNP levels in patients with and without LV dilatation were 3045 and 30.82 pg/ml. There was a significant correlation between the severity of MR and NT-proBNP levels (P < 0.001), thus a significant correlation between LV dilatation and NT-proBNP levels (P = 0.013). A cutoff value of 2598.50 pg/ml was obtained with a sensitivity value of 90% and a specificity of 90.5% for NT-proBNP levels against severe MR. A cutoff value of 199.35 pg/ml was obtained with a sensitivity value of 73.3% and a specificity of 75% for NT-proBNP levels on LV dilatation. A cutoff value of 2598.50 pg/ml was obtained with a sensitivity value of 85.7% and a specificity of 79.2% for NT-proBNP levels against severe MR with LV dilatation.

Conclusion: There was a significant relationship between NT-proBNP levels and the severity of MR and LV dilatation in children with RHD.