Forward and Backward Aortic Components and Reflection Indexes in Children and Adolescents: Determinants and Role in High Pressure States

ZOCALO, YANINA; CURCIO, SANTIAGO; CABRERA-FISCHER, EDMUNDO I.; GARCIA-ESPINOSA, VICTORIA; GIACHETTO, GUSTAVO; CASTRO, JUAN M.; CHIESA, PEDRO; BIA, DANIEL

Current Hypertension Reviews

Bentham Science Publishers B. V.

Lugar: Beijing; Año: 2018 vol. 14

1573-4021

Abstract: The aims were: 1) to characterize the association between aortic wave components or indexes (backward [Pb], forward [Pf], Pb/Pf ratio and augmentation index [AIx]) and demographic, anthropometric, hemodynamic, and arterial parameters in healthy children and adolescents, in order to determine potential explanatory variables; 2) to generate multivariate prediction models for the associations (including the mentioned parameters), to contribute to understand main determinants of Pf, Pb, Pb/Pf and AIx levels; 3) to identify if differences in wave reflection indexes observed in high blood pressure states (HBP) could be explained by differences in the mentioned parameters. Methods: Healthy children and adolescents (n=816, females: 386; Age: 3-20 years) were evaluated. Cardiovascular evaluation included central aortic pressure and components (Pb, Pf, Pb/Pf and AIx) determination (SphygmoCor [SCOR] and Mobil-o-Graph [MOG]) and anthropometric and arterial non-invasive evaluation (carotid-femoral and carotid-radial pulse wave velocity (PWV), PWV ratio, carotid intima-media thickness, carotid and femoral artery distensbility, cardiac output, systemic vascular resistances [SVR]). Simple and multiple regression models were constructed to determine the aortic wave reflection parameters main explanatory variables. Normotensive and HBP groups were compared, and differences in wave reflection indexes were analyzed before and after control for wave reflection explanatory variables. Equivalence between wave-derived data obtained using SCOR and MOG were assessed (correlation and Bland-Altman analyses). Results and Conclusions: heart rate (HR), peripheral pulse pressure, body height and weight were the variables that in isolation (simple associations) or combined (multiple associations), showed the major capability to explain interindividual differences in Pf, Pb, Pb/Pf and AIx. In a second level, in terms of such explanatory capacity was the arterial stiffness, being the carotid the artery with major contribution to explain Pf, Pb, Pb/Pf ratio and AIx variations. HBP states were associated with higher Pf, Pb, AIx and with a lower Pb/Pf ratio; those findings were observed, together with higher weight, arterial stiffness and HR. After adjusting for anthropometric characteristics, HR, cardiac output and SVR, subjects from the HBP group showed greater Pf and Pb levels. Then, Pf and Pb characteristics associated with HBP states would not be explained by anthropometric or hemodynamic factors. SphygmoCor and Mobil-O-Graph systems did not give similar levels of pulse wave derived indexes, but there were both systematic and proportional differences between data obtained with the referred devices