Association of Plasma B-Type Natriuretic Peptide Levels with Shunt Size in Young Adults with Atrial Septal Defect

Abstract

This study was designed to investigate the validity of brain natriuretic peptide (BNP) levels for the estimation of the shunt size in young adults with atrial septal defect (ASD), and to determine the relationship between BNP levels and echocardiographic parameters of right heart chambers. Fifty-six patients with ASD (mean age 22.9 ± 2.0 years) were studied. The control group consisted of 31 age-gender matched healthy volunteers (mean age 22.7 ± 1.9 years). Coventional echocardiography, tissue Doppler imaging (TDI) and plasma BNP level measurement was performed in all participants. The ratio of pulmonary to systemic blood flow (Qp/Qs) was measured noninvasively using transthoracic echocardiography. Plasma BNP levels were significantly higher in ASD patients than in controls (42.9 ± 29.4 vs. 8.3 ± 2.6 pg/mL, P < 0.05). Pulmonary artery pressure (PAP) (P = 0.0001), right atrium (RA) volume (P = 0.0001), and right ventricular end-diastolic volume (RVEDV) (P = 0.0001) values were higher in ASD patients. There was a powerful correlation between plasma BNP levels and Qp/Qs ratio (r = 0.71, P < 0.0001). The plasma BNP levels significantly correlated with PAP (r = 0.61, P < 0.0001), RA volume (r = 0.54, P < 0.0001), RVEDV (r = 0.55, P < 0.0001), and right ventricular myocardial performance index (r = 0.50, P < 0.0001). This study shows that there is a significant correlation between right heart echocardiographic parameters and concentrations of BNP in the plasma of young adults with ASD. BNP levels may provide a supplemental data to predict of shunt size in these patients.