Association between brain natriuretic peptide and cardiac dysfunction in hypertensive pregnancy disorders

Abstract

Objective: The aim of this work is to identify the correlation between serum brain natriuretic peptide (BNP) and left ventricle (LV) systolic and diastolic function in hypertensive pregnancy disorders (HPD) through echocardiographic parameters.

Study design: Eighty-seven pregnant patients were included, 23 with normotensive pregnancy (NP), 28 with gestational hypertension (GH) and 36 with preeclampsia (PE). Conventional 2D echocardiography was used to evaluate systolic and diastolic function such as E/a, E/e', LV mass index, LV ejection fraction, as well as left atria (LA) diameters, LA indexed volume, LV strain and LA strain (LAS). Brain natriuretic levels (BNP) blood levels were also determined.

Main outcome measures: The serum levels of BNP were higher in patients with PE [median (interquartile range, IQR)] 189 (142-215) pg/ml and GH 105 (46-162) pg/ml compared to NP 23 (9-33) pg/ml, (p = 0.001). BNP levels had a negative correlation with LAS (Rho = -0.79, p < 0.001). Preeclampsia patients had lower LAS [median (IQR)] 22% (20%-24%) compared to the GH group 23% (20%-24%) and NP 35% (34% -35%), p = 0.001. Classification and Regression Trees multivariate analysis found patterns that define trends to form mutually excluding homogeneous groups such as: a) First parameter that separates 2 groups is septal e > 8.2 or < 8.2b), BNP serum levels above 89 pg/ml, and c) LAS increases the discriminatory performance to detect and define the diastolic dysfunction or not.

Conclusions: At least one third of women with HPD had moderate diastolic dysfunction. The degree of diastolic dysfunction was negatively correlated with serum BNP levels and severity of HPD. LAS increase discriminatory performance to identify diastolic dysfunction in HPD.

Keywords: Brain natriuretic peptide; Gestational hypertension; Hypertensive disorders of pregnancy; Left atrium; Left ventricular dysfunction; Preeclampsia.