Amino-terminal pro-brain natriuretic peptide in children with latent rheumatic heart disease

Background : Rheumatic heart disease (RHD) is a global cause of early heart failure. Early RHD is characterized by valvar regurgitation, leading to ventricular distention and possible elaboration of amino-terminal pro-brain natriuretic peptide (NT-proBNP). We investigated the ability of NT-proBNP to distinguish cases of latent RHD detected by echocardiographic screening from the controls. Materials and Methods : Ugandan children (N = 44, 36% males, mean age: 12 +/- 2 years) with latent RHD (cases) and siblings (controls) by echocardiography were enrolled. Cases and controls were matched for age and sex, and they had normal hemoglobin (mean: 12.8 mg/dL). Children with congenital heart disease, pregnancy, left ventricular dilation or ejection fraction (EF) below 55%, or other acute or known chronic health conditions were excluded. RHD cases were defined by the World Heart Federation (WHF) 2012 consensus guideline criteria as definite. Controls had no echocardiography (echo) evidence for RHD. At the time of echo, venous blood samples were drawn and stored as serum. NT-proBNP levels were measured using sandwich immunoassay. Paired t-tests were used to compare NT-proBNP concentrations including sex-specific analyses. Results : The mean NT-proBNP concentration in the cases was 105.74 +/- 67.21 pg/mL while in the controls, it was 86.63 +/- 55.77 pg/mL. The cases did not differ from the controls (P = 0.3). In sex-specific analyses, male cases differed significantly from the controls (158.78 +/- 68.82 versus 76 +/- 42.43, P = 0.008). Female cases did not differ from the controls (75.44 +/- 45.03 versus 92.30 +/- 62.35 respectively, P = 0.4). Conclusion : Serum NT-proBNP did not distinguish between latent RHD cases and the controls. Sex and within-family exposures may confound this result. More investigation into biomarker-based RHD detection is warranted.