Abstract 16783: Risk Factors Associated With Progression of Carotid Wall Volume and Plaque Lipid Content in Patients With Established Vascular Disease and Treated With Intensive Lipid Therapy in the AIM-HIGH Study
Objective: Previous studies showed that large wall volume (WV) and lipid-rich necrotic core (LRNC) are associated with increased risk of cardiovascular events. We examined the association between risk factors and progression of carotid WV and plaque LRNC over 2 years (yrs) in patients with established vascular disease and undergoing lipid therapy in AIM-HIGH.
Methods: 156 AIM-HIGH subjects had qualified baseline and 2-yr follow-up scans. MR images were analyzed by Core Lab reviewers, blinded to therapy, lab results and clinical course using published criteria for quantifications of WV and LRNC and detection of calcium (CA) and intraplaque hemorrhage (IPH). %WV was calculated using the formula: WV/total vessel volume) X 100% for all available slices. %LRNC was calculated using the formula: (LRNC volume/WV) X 100% for slices containing LRNC. Of 156, 89 were on statin+placebo for extended-release niacin (ERN) and 67 received statin+ERN. Multivariate linear regression analysis was performed to identify factors associated with progression or regression of %WV or %LRNC. Potential factors considered were 3 plaque features (LRNC, CA and IPH), 9 clinical risk factors, and 9 baseline and in-study lipid measurements (cholesterol, apolipoproteins and Lp(a)).
Results: There were no statistically significant differences in changes of %WV and %LRNC between the statin+placebo and statin+ERN groups. %WV increased on average by 0.2±1.1%/yr (p=0.02) in the 156 subjects. Increased progression of %WV over 2 yrs was independently associated with presence of LRNC (p=0.02), presence of CA (p=0.003) and higher baseline or in-study Lp(a) level (p=0.01). In the 80 subjects with LRNC, of which 18 had IPH at baseline or 2 yrs, overall %LRNC decreased significantly on average. Higher baseline ApoB/ApoA1 ratio (p=0.02) and presence of IPH (p<0.001) were independently associated with increased progression (or less regression) of %LRNC over 2 yrs.
Conclusions: In patients with established vascular disease and treated with either statin or with statin plus ERN in AIM-HIGH, increased progression of %WV was correlated with presence of LRNC, presence of calcium and higher Lp(a) levels. Greater reduction of %LRNC was associated with lower baseline ApoB/ApoA1 ratio and absence of IPH.
Author Disclosures: X. Zhao: None. K.D. O’Brien: None. D. Hippe: None. D. Isquith: None. J. Sun: None. N. Balu: None. M.B. Neradilek: None. K. Yamada: None. G. Canton: None. J.R. Crouse: None. T.J. Anderson: None. J. Huston: None. N. Polissar: None. T. Hatsukami: None. C. Yuan: None.
- © 2014 by American Heart Association, Inc.