Elevation of atrial natriuretic peptide prohormone. Hemodynamic background of the elevation of N-terminal natriuretic peptide prohormone in children with congenital heart disease

We postulated previously that variables related to pulmonary flow are independent predictors of levels of atrial natriuretic peptide in children with congenital heart disease. The aim of this study was to test this hypothesis in relation to other hemodynamic and clinical variables. During catheterization we measured the levels of plasma N-terminal atrial natriuretic peptide prohormone in the plasma of 68 children with congenital heart disease. All had undergone complete clinical, echocardiographic and invasive hemodynamic investigations. The influence on the prohormone was analyzed for 10 different variables in a multiple linear regression model. The variability could be explained in large parts (adjusted R2 =77.2%) by variations in atrial pressures or sizes, together with the degree of excessive pulmonary blood flow and signs of heart failure. A value for atrial natriuretic peptide prohormone above 800 pmol/l predicted hemodynamic imbalance (defined as elevated pressures in left or right atrium or the pulmonary arteries, and/or Qp/Qs > 1.5) with a specificity of 94%, a sensitivity of 73%, a positive likelihood ratio of 12.2, and a negative likelihood ratio of 0.29. In conclusion, variables related to pulmonary blood flow are influential determinants of the levels of atrial natriureic peptide in children with congenital heart disease. Atrial pressures, and symptoms of heart failure are also of major importance.