Dynamics of intima‑media complex thickness in children with familial hypercholesterolemia on the background of lipid‑lowering therapy: A retrospective study of real clinical practice data

Abstract

Introduction. Pediatric familial hypercholesterolemia (FH) is characterized by prolonged exposure to elevated low-density lipoprotein cholesterol (LDL-C) and early development of subclinical vascular injury. Carotid intima-media thickness (cIMT) is a widely used ultrasound marker of vascular phenotype in children; therefore, ageand sex-specific standardization is essential. Aim . To assess the prevalence of increased cIMT and its longitudinal changes in children and adolescents with FH in real-world clinical practice, and to evaluate associations between cIMT changes, LDL-C dynamics, and lipid-lowering therapy regimens. Materials and methods . We conducted a retrospective single-center cohort study (2019–2025). Patients aged 0–17 years with clinically verified definite/probable FH. The index visit corresponded to a control visit after approximately 6 months of lifestyle intervention, during which carotid ultrasound with cIMT measurement was performed; lipid-lowering pharmacotherapy was initiated after the index assessment. Longitudinal cIMT analyses required ≥ 2 measurements and an interval ≥ 180 days. Results. The database comprised 1015 visits from 473 patients; cIMT was recorded in 760/1015 (74.9%) visits. The longitudinal sample included 365 patients; the observation interval was 482 days. At the index visit, cIMT was 0.40 mm; Doyon SDS (Standard Deviation Score) was 0.586; cIMT ≥ 95th percentile was present in 27.4%, and carotid plaque in 2.5%. By the last ultrasound examination, SDS decreased to 0.503; and the Doyon cIMT percentile rank (0–1) decreased to 0.692, while the median absolute cIMT did not change, consistent with discretization/rounding of routine measurements despite a small but statistically detectable shift in paired differences. Conclusion . In children and adolescents with FH in real-world practice, cIMT dynamics are most clearly captured by standardized measures and are associated with the magnitude of LDL-C reduction and attainment of individualized LDL-C targets.