The long-term vascular effects following childhood hematopoietic stem cell transplantation (HSCT) are not well characterized. We compared arterial wall morphology and function using very-high resolution ultrasound (25-55 MHz) in 62 patients following autologous (n = 19) or allogenic (n = 43) HSCT for childhood malignancies and hematological disease (median age 25.9 years, IQR 21.1-30.1; median follow-up time 17.5 years IQR 14.1-23.0) with an age matched healthy control group (n = 44). Intima-media thickness of carotid (CIMT 0.49 ± 0.11 vs. 0.42 ± 0.06 mm, p < 0.001), brachial, femoral, radial arteries, and local carotid stiffness, but not adventitial thickness, were increased (p < 0.001). Diffuse intimal thickening (>0.06 mm) of femoral or radial arteries (n = 17) and subclinical carotid or femoral plaques (n = 18) were more common (p < 0.001). Radiation predicted plaques (p < 0.001) and local carotid stiffness (p < 0.001), but not intimal thickening. CIMT was predicted by age, BMI >30 kg/m2, hsCRP >2.5 mg/L, hypertension, HbA1c > 42 mmol/L, and cumulative anthracycline >150 mg/m2. Cumulative metabolic syndrome criteria and cardiovascular disease (CVD) risk factors were more common among HSCT and related with CIMT (p < 0.001), but CIMT was similar among controls and HSCT without CVD risk factors. Long-term childhood HSCT survivors show early arterial aging related with radiation, metabolic, and CVD risk factors. Prevention of risk factors could potentially decelerate early arterial wall thickening.
Keywords: atherosclerosis; early vascular ageing; hematopoietic stem cell transplantation; radiotherapy; very-high resolution ultrasound.