Pediatric Heart Network Echo Z Scores

Study Questions:

What are the Z scores in the pediatric population for common echocardiographic measurements adjusted for body surface area (BSA) and stratified by age, sex, race, and ethnicity?

Methods:

Echocardiogram data from 19 centers participating in the Pediatric Heart Network were collected from normal echocardiograms from nonobese healthy children ≤18 years of age. Measurements were performed at a Core Laboratory. Demographic data included age, sex, race, and ethnicity. Z score models involved indexed parameters that were normally distributed without residual dependence on BSA. The models were tested for the effects of age, sex, race, and ethnicity. A <5% difference was considered clinically insignificant because interobserver variability for echocardiographic measurements are reported as ≥5% difference.

Results:

Of 3,566 subjects, 90% had measurable images. Although multivariable regression demonstrated statistically significant impact of age, sex, race, and ethnicity for all outcomes, all effects were clinically insignificant. Z scores were therefore independent of age, sex, race, and ethnicity for each measurement.

Conclusions:

Echocardiographic Z scores based on BSA were derived from a large, diverse, nonobese, and healthy North American population. Age, sex, race, and ethnicity have a small but statistically significant impact on scores, which is not clinically important.

Perspective:

This report from the Pediatric Heart Network puts forth a new set of normal reference values for pediatric echocardiography based on BSA. An important contribution of this project is that age, sex, race, and ethnicity do not have a clinically important impact on Z scores. There is the potential for wide application of this system, specifically in North America, where it was developed. The regression equations and a Z score calculator will ultimately be available on the Pediatric Heart Network website (www.pediatricheartnetwork.com).

Clinical Topics: Congenital Heart Disease and Pediatric Cardiology, Noninvasive Imaging, Congenital Heart Disease, CHD & Pediatrics and Imaging, CHD & Pediatrics and Quality Improvement, Echocardiography/Ultrasound

Keywords: AHA17, AHA Annual Scientific Sessions, Body Surface Area, Diagnostic Imaging, Echocardiography, Ethnic Groups, Heart Defects, Congenital, Nomograms, North America, Pediatrics


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