Abstract 12376: Clinical Factors Associated With High-risk Carotid Plaque Features as Assessed by MRI in Patients With Established Vascular Disease in the AIM-HIGH Study
Objective: High-risk atherosclerotic plaque features (HRAPF) have not been studied in patients with established vascular disease and well treated for LDL-C and blood pressure (BP). Clinical factors associated with HRAPF such as AHA type-VI lesions, presence of lipid-rich necrotic core (LRNC) and higher LRNC volume by carotid MRI in the AIM-HIGH MRI sub-study were identified.
Methods: At baseline, 214 AIM-HIGH participants (mean age 61±9 years, 82% male and 88% white) underwent carotid MRI scans at 21 study sites using a standard protocol and had acceptable image quality for assessment. At the time of the MRI scan, 94% of the subjects were on statins, LDL-C was 77±27 mg/dl, and mean BP was 128/75 mmHg. MR images were analyzed by Core Lab reviewers, blinded to therapy, lab results and clinical course using published criteria for MRI analysis and MRI-modified AHA lesion type. Clinical factors which had a statistically significant association with HRAPF were identified by multivariate logistic or linear [per 1 standard deviation (SD)] regression and summarized as adjusted odds ratios (ORs) and 95% confidence intervals (CIs).
Results: Of the 214 subjects, 23%, 10%, 43%, 11% and 14% were found to have AHA I-II, III, IV-V, VI and VII type lesions, respectively. Type-VI lesions (possible surface defect, hemorrhage or thrombus) were significantly correlated with older age (OR=1.3 for 1 year older, CI=1.1-1.4, p≤0.001), history of cerebrovascular or carotid disease (OR=3.9, CI=1.2-12, p=0.02) and higher levels of Lipoprotein(a) (OR=2.0, CI=1.1-3.5, p=0.02), but, negatively associated with metabolic syndrome (OR=0.3, CI=0.1-0.9, p=0.04). Presence of LRNC seen in 52% of subjects was significantly associated with male gender (OR=2.9, CI=1.3-6.8, p=0.01), white race (OR=3.5, CI=1.3-9.8, p=0.01) and lower level of HDL-3 (OR=0.7, CI=0.5-0.9, p=0.02), but, negatively associated with BMI (OR=0.7, CI=0.5-0.9, p=0.02). Also, in those with LRNC, mean LRNC volume was 19% higher for each 1 SD decrease in ApoA1 (CI=0.5-35%, p=0.048).
Conclusions: In subjects with established vascular disease and well treated for LDL-C and BP, Lipoprotein(a), HDL-3 or ApoA1 are associated with HRAPF. Surprisingly, metabolic syndrome and BMI appear to have negative association with HRAPF.
- © 2013 by American Heart Association, Inc.