Pediatric continuous reference intervals of coronary artery diameter by echocardiography in healthy Chinese children population.

The aim of this study was to establish body surface area (BSA)-dependent Z-score continuous reference intervals of coronary artery diameter measured by Echocardiography in healthy Chinese children population. Echocardiography measured 1221 healthy Chinese children's coronary artery diameters, including the LMCA, LAD, LCX, RCA-pro, RCA-mid, and RCA-dis. We employed the LMS (Lambda-Mu-Sigma) method for the model and the Haycock equation for the BSA estimation. The coronary artery diameter Z-score continuous reference intervals were established using the LMS method and passed the internal and external validation. CONCLUSIONS: The study outcome provides BSA-dependent Z-score continuous reference intervals for the coronary artery diameters in healthy Chinese children. There is a web Z-score calculator with convenient application for clinicians and ultrasound doctors, facilitating subsequent external validations in a larger population. WHAT IS KNOWN: • Echocardiography is the primary non‑invasive modality for assessing coronary artery (CA) diameter in children, and body surface area (BSA)‑dependent Z‑scores provide a more objective evaluation than absolute values. • The LMS (Lambda‑Mu‑Sigma) method is an internationally accepted approach for establishing continuous reference intervals, as used in the WHO child growth standards. WHAT IS NEW: • This study establishes BSA‑dependent Z‑score continuous reference intervals for six coronary artery segments (LMCA, LAD, LCX, RCA‑pro, RCA‑mid, RCA‑dis) specifically in healthy Chinese children aged 0 days to 18 years. • It provides a validated, LMS‑based model along with an online Z‑score calculator and a fully reproducible computational procedure, addressing the lack of updated, ethnicity‑specific continuous reference intervals for the Chinese pediatric population.