Lipoprotein (a) levels predict progression of carotid atherosclerosis in subjects with atherosclerotic cardiovascular disease on intensive lipid therapy: an analysis of the AIM-HIGH Carotid MRI Sub-study

OBJECTIVE: To assess whether lipoprotein (a) [Lp(a)] levels and other lipid levels were predictive of progression of atherosclerosis burden as assessed by carotid MRI in subjects who have been treated with low density lipoprotein cholesterol (LDL-C) lowering therapy and participated in the AIM-HIGH (Atherothrombosis Intervention in Metabolic Syndrome with Low HDL/High Triglycerides: Impact on Global Health Outcomes) Trial. APPROACH: AIM-HIGH was a randomized, double-blind study of subjects with established vascular disease, elevated triglycerides, and low high-density lipoprotein cholesterol. One hundred fifty-two AIM-HIGH subjects underwent both baseline and 2-year follow-up carotid artery MRI. Plaque burden was measured by the percent wall volume (%WV) of the carotid artery. Associations between annualized change in %WV with baseline and on-study (1 year) lipid variables were evaluated using multivariate linear regression. P-values were adjusted for multiple comparisons. RESULTS: Average %WV at baseline was 41.6 ± 6.8% and annualized change in %WV over 2 years ranged from −3.2% to 3.7%/year (mean: 0.2 ± 1.1%/year, p=0.032). Increases in %WV was significantly associated with higher baseline Lp(a) [β = 0.34 per 1-SD increase of Lp(a), 95% CI: 0.15 to 0.52, p