Abstract 3021: Cardiovascular Risk Factors Affect Age Distribution of Atherosclerotic Disease Burden as Assessed by Magnetic Resonance Imaging
Introduction: Presence of cardiovascular risk factors (RF) at a young age is associated with earlier onset of cardiovascular diseases and death. RF by themselves are imprecise measures of extent of vascular pathology or disease burden. Timing of specific early interventions could be more precise if the burden of atherosclerosis could be measured after identification of the high risk state. Hypotheses:
Vascular MRI may be used to quantify the burden of subclinical atherosclerotic disease in children and adolescents with high cardiovascular risk and
the amount of subclinical atherosclerosis in this young high-risk population will be comparable to an adult population with an intermediate 10-year risk by Framingham Risk Score (FRS).
Methods: Black-blood MRI of the aorta and extracranial carotid arteries was performed in 196 subjects (ages 8 to 87, 67 females) distributed into 5 age groups: Group 1 (n=40, 14.12±5.51 years, age 8–19, all at high-risk cardiovascular distribution); Groups 2,3,4,5 consisting of 10-year increments (n=156, 60.0± 21.5 years, ages 20 to 87, FRS 12%±0.12). For each subject, 36 to 48 cross-sectional images of the aorta and 12 to 24 images of carotids were analyzed. Average arterial wall area (AWA) was calculated and normalized with lumen diameter (nAWA) in each resulting image to compensate for age-related arterial size variation. Average imaging time was 50 minutes. Measurements in Group 1 were compared to the older age groups.
Results: Analysis of 3,853 aortic and 3,352 carotid imaging slices showed that nAWA increases with age earliest in common carotid arteries followed by the descending thoracic aorta in intermediate risk Groups 2 to 5. Post-Hoc ANOVA showed a bimodal distribution with the nAWA of Group 1 (Carotid 0.32±0.05; Aorta 0.21±0.03) similar to those of intermediate risk adults in their 50s and 60s -Groups 4 and 5 (Carotids 0.34±0.06; Aorta 0.20±0.03).
Conclusion: Atherosclerotic Disease Burden in children and adolescents with high-risk is equivalent to an intermediate risk adult population as assessed by high-resolution MRI. MRI is rapid, non-invasive, and highly reproducible and may facilitate risk-stratification and monitoring of young patients.