Clinical Investigation
Echocardiography in Children
New Comprehensive Reference Values for Arterial Vascular Parameters in Children

https://doi.org/10.1016/j.echo.2020.03.001Get rights and content

Highlights

  • Arterial vascular parameters may help detect early cardiovascular diseases.

  • Current pediatric reference values are scarce and limited to few vascular parameters.

  • The authors present pediatric reference values for a full set of vascular parameters.

  • Expressed as Z scores, vascular parameters can be used for all ages and body sizes.

Background

Noninvasive measurements of vascular parameters can be used for the detection and risk stratification of cardiovascular diseases. Most vascular parameters are influenced by age and body size, but pediatric reference values are scarce and limited to a few parameters. The aim of this study was to develop pediatric reference values and Z score equations for a comprehensive set of vascular parameters.

Methods

A total of 292 healthy subjects aged 0 to 18 years were prospectively recruited. Stiffness index β, pressure-strain elastic modulus, common carotid intima-media thickness, brachial flow-mediated dilation, radial augmentation index, central and right arm peripheral artery pulse-wave velocities, and pulse-wave velocity ratio were assessed. Normalization for age and anthropometric variables was performed using parametric multivariate regression modeling. Z scores were assessed for heteroscedasticity, residual association with age and body size, and distribution.

Results

Multivariate regression models with various combinations of height, weight, and age were used to obtain Z scores that were independent of age and body size. There was no residual association between Z scores and body size, age, or body mass index. There was no significant departure from the normal distribution.

Conclusions

The authors present reference values and Z score equations for a comprehensive set of vascular parameters during childhood. Further studies are necessary to assess their usefulness in detecting the vascular signs of subclinical atherosclerosis and chronic diseases, including congenital heart disease.

Section snippets

Subjects

This study was approved by the Hospital for Sick Children's research ethics board and carried out in accordance with the code of ethics of the World Medical Association (Declaration of Helsinki). Study participation required written informed parental consent as well as assent from participants who were old enough to understand the proposed research.

Healthy subjects aged 0 to 18 years were recruited from local public schools and from the low-risk heart murmur referral clinic at the Hospital for

Study Population

Table 1 and Figure 1 respectively detail the characteristics and age distribution of the 292 study subjects. Stiffness index, CPWV, and pressure-strain elastic modulus were obtained in 273 children (age range: 0.0–17.9 years), carotid intima-media thickness in 204 children (age range: 8.0–17.9 years), flow-mediated dilation in 182 children (age range: 8.3–17.9 years), and augmentation index, cfPWV, crPWV, and PWV ratio in 198 children (age range: 5.5–17.9 years). The median and interquartile

Discussion

In this study, we propose pediatric reference values for a comprehensive set of vascular parameters. Using multivariate regression models, we were able to adjust for the physiologic effects of weight, height, and age. The proposed Z scores are independent of these variables, and their validity is strengthened by the absence of departure from a normal distribution.

The relationship of vascular parameters with age and anthropometric variables is complex. In contrast to adults, there are

Conclusion

In this study, we propose Z score equations for pediatric reference values for a comprehensive set of vascular parameters. These reference values should help better differentiate the physiologic effects of age and body size from the pathologic effects of disease. Further studies are needed to evaluate the role of these vascular parameters in identifying cardiovascular risks.

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    Dr. Torigoe holds a scholarship from Niigata Prefectural Welfare Federation of Agricultural Cooperative, Japan. Dr. Dallaire is supported in part by unrestricted salary support from Fonds de Recherche du Québec - Santé.

    Conflicts of interest: None.

    Drs. Torigoe and Dallaire contributed equally to this work.

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