Vascular structure and stiffness in pediatric Mulibrey nanism using ultra-high frequency ultrasound

Mulibrey nanism (MUL) is a disorder with growth delay and congestive heart failure determining prognosis. We aimed to delineate arterial and venous morphology, and arterial stiffness in a representative pediatric MUL cohort. Twenty-three MUL and 23 individually sex and age-matched healthy controls were prospectively assessed in a cross-sectional study with ultra-high frequency ultrasound (48-70 MHz). Heart failure was present in 7 MUL patients, with severe congestive heart failure in 2. Pericardiectomy had been performed in 6 MUL. Arterial lumen diameters and arterial wall layer thickness (intima-media thickness and adventitia thickness) were smaller in MUL patients, but appropriate for body size when compared with controls. Systolic and diastolic blood pressure, aortic and carotid compliance, stiffness as well as central aortic pulsed wave velocity were all similar in MUL compared with controls. Plasma pro-BNP levels were variably elevated (>300 ng/L) in 9/23 MUL patients and in 4/18 MUL patients older than 5 years of age. Internal jugular vein (mean difference 0.054 mm, CI95% 0.024-0.084) and cubital vein (0.046 mm, CI95% 0.013 - 0.078) total wall thickness was elevated in MUL compared with controls. There were no statistically significant relations between vascular parameters and clinical or laboratory signs of heart failure or pericardiectomy. Arterial lumen, wall layer thickness and stiffness are appropriate for body size in MUL, and like healthy controls. Mild venous wall thickening in the upper body region may be due to increased venous pressures related to remodelling caused by diastolic heart failure.