Establishing an appropriate Z score regression equation for Chinese pediatric coronary artery echocardiography: a multicenter prospective cohort study

Shu-Min Fan,Shan-Liang Zhu,Yang Xu,Bei Xia,Wen-Juan Chen,Shu-Bao Chen,Wei Yu,Wei-Xiang Liu,Zhi-Xia Wu,Qing-Hua Liu,Jie-Qing Min,Mei Jin

doi:10.1186/s12887-021-02877-9

Abstract

BackgroundZ score utility is emphasized in classifying coronary artery lesions in Kawasaki disease patients. The present study is the largest such multicenter Chinese pediatric study about coronary artery diameter reference values and Z score regression equation to date. It is useful in Chinese pediatric echocardiography.MethodsA multicenter cohort was assembled, which consisted of 852 healthy children between 1 month and 17 years of age, ten children were excluded because their ultrasound images were not clear, or lost in following up. Diameters of the right coronary artery, left coronary artery, and left anterior descending coronary artery were assessed using echocardiography. Data were body surface area (BSA)-corrected using BSA calculated via either the Stevenson BSA formula or the Haycock BSA formula. Coronary artery diameter reference values and Z score regression equations were established for use in the Chinese pediatric population.ResultsNo difference was observed between coronary artery diameter data corrected using BSAste or BSAhay. Of the five assessed regression models, the exponential model exhibited the best fit and was therefore selected as the basis for derivation of the SZ method. When comparing Z scores, those produced by the SZ method conformed to the standard normal distribution, while those produced by the D method did not. In addition, there was a statistically significant difference between Z scores produced by the SZ and D methods (P < 0.05).ConclusionsCoronary artery diameter reference values for echocardiography were successfully established for use in the Chinese pediatric population, and a Z score regression equation more suitable for clinical use in this population was successfully developed.

Highlights

Z score utility is emphasized in classifying coronary artery lesions in Kawasaki disease patients
Echocardiography-determined coronary artery diameters corrected using body surface area (BSA) calculated via two different formulae
Exponential model performance based on BSA Stevenson formula (BSAste)-corrected values was as follows: lnyLCA = 1.0042 + 0.3494lnx (R2 = 0.678, residual standard error (RSE) = 0.114, Akaike information criterion (AIC) = − 932.57), lnyLAD = 0.8013 + 0.3448lnx (R2 = 0.641, RSE = 0.120, AIC = − 849.8), and lnyRCA = 0.8107 + 0.3098lnx (R2 = 0.4806, RSE = 0.150, AIC = − 604) (Table 3)

Summary

Introduction

Z score utility is emphasized in classifying coronary artery lesions in Kawasaki disease patients. The present study is the largest such multicenter Chinese pediatric study about coronary artery diameter reference values and Z score regression equation to date. It is useful in Chinese pediatric echocardiography. Echocardiography is commonly used to evaluate pediatric patients for coronary artery disease (CAD). The most recent American Heart Association guidelines recommend body surface area (BSA)-corrected coronary artery diameter as the gold standard, and emphasize Z score utility in evaluating coronary artery injury risk and in classifying coronary artery lesions in Kawasaki disease patients. The American Society of Echocardiography recommends the use of Z scores in pediatric cardiology [1]. These scores indicate the distribution of measurements about the mean within a healthy population, and facilitate comparison of datasets exhibiting differential means and distributions (such as datasets deriving from children of different ages and sizes)

Methods

Results

Conclusion