Plasma levels of B-type natriuretic peptide in patients with tetralogy of Fallot after surgical repair

Abstract

Objective To evaluate the utility of plasma BNP measurement in the long term follow-up of patients with surgically repaired tetralogy of Fallot (TOF). Methods From 2002 to 2008, plasma BNP concentration was measured in 130 patients with TOF at the age of mean 16.1 ± 7.1 years and mean 13.0 ± 6.5 years after surgically repair. BNP levels were compared to age and gender-specific normal values, results of exercise testing, clinical, electrocardiographic, and echocardiographic data. Results BNP was < 200 pg/ml in all and elevated in 60% of patients. Higher values were found in females ( p = 0.001), in patients waiting for pulmonary valve replacement ( p < 0.001), and in NYHA class II compared to NYHA I patients ( p = 0.012) with an inverse correlation between BNP and exercise time ( r = − 0.59, p < 0.001). BNP was correlated with right ventricular dilatation ( r = 0.29, p = 0.005) and severity of both tricuspid ( r = 0.22, p = 0.015) and pulmonary regurgitation ( r = 0.20, p = 0.029). Longitudinal data revealed increasing BNP levels before ( p = 0.04) and a BNP decrease after pulmonary valve replacement ( p = 0.03), but no change in patients without surgery. Conclusions In patients with surgically repaired TOF, plasma BNP is significantly correlated with right ventricular volume load. In clinical practice a considerable overlap limits the estimation of right ventricular volume load by BNP, but longitudinal evaluation helps to appoint the appropriate timing of pulmonary valve replacement.