Abstract 8: Effect of Intensive Lipid Therapy on Plaque Lipid Depletion as Assessed by Magnetic Resonance Imaging
Background: Previously we demonstrated plaque lipid depletion by carotid MRI during lipid lowering. Effect of different lipid therapy on plaque lipid content was investigated.
Methods: Subjects (n=182) with coronary or carotid artery disease, apoB ≥120 mg/dl, and lipid treatment history <1 year were randomized to: (1) single therapy (Rx) - atorvastatin (Atorva) (10-80 mg/day); or (2) double Rx - Atorva plus extended release-niacin (ERN) (2 g/day); or (3) triple Rx - Atorva, ERN plus colesevelam (3.8 g/day) with appropriate placebos for 2 years. These Rx lowered treatment-group average LDL-C by 38%, 29%, 45% and triglycerides by 17%, 22%, 39%, and raised HDL-C by 7%, 24%, 30%. Of the 182 subjects who underwent high-resolution, multi-contrast bilateral carotid MRI scans at baseline, 46 were identified with lipid-rich necrotic core (LRNC) and completed 2-year follow-up scans by July 2013. Cross-sectional images (10 slices on average) with 2 mm thickness were obtained and centered at the carotid bifurcation. All images were analyzed for quantifications of wall area and plaque composition while blinded to therapy, lab results and clinical course, using the previously published MRI criteria. LRNC-volume (LRNC-V) and %LRNC (LRNC area/wall area) were compared pre- and post-therapy in each of the 3 Rx groups using Mann-Whitney test.
Results: Overall, the 46 subjects with measurable LRNC at baseline had a significant plaque lipid content reduction. LRNC-V decreased from 58.8±9.0 to 39.7±10.2 mm3 (p<0.001) and %LRNC from 13.3±1.0 to 8.1±1.2 (p<0.001) after 2 years of Rx. Single Rx (n=17) showed non-statistical significant reductions in LRNC-V (78.0±20.7 vs. 69.8±25.3 mm3, p=0.2) and %LRNC (14.3±1.9 vs. 11.2±2.8, p=0.2). However, double Rx (n=16) had significant reductions in LRNC-V (51.9±10.3 vs. 21.4±6.0 mm3, p<0.001) and %LRNC (13.3±1.5 vs. 6.1±1.0, p=0.001). Triple Rx (n=13) also showed significant reductions in LRNC-V (42.3±9.8 vs. 23.1±6.9 mm3, p=0.005) and %LRNC (12.1±1.9 vs. 6.6±1.9, p=0.002).
Conclusions: Intensive combination lipid therapy of atorvastatin plus niacin or atorvastatin, niacin and colesevelam significantly depletes carotid plaque lipid content as assessed by MRI over 2 years.
Author Disclosures: X. Zhao: Research Grant; Modest; AbbVie, Merck, Daiichi-Sankyo, Pfizer. E. Hulphers: None. D. Iquith: None. H. Bai: None. P. Shadzi: None. A. Contreras: None. M. Neradilek: None. E. Gill: None. P. Colletti: None. T. Hatsukami: None. C. Yan: None.
- © 2014 by American Heart Association, Inc.