Abstract 5531: Early Detection of Vessel Wall Size Changes Following Intensive Lipid therapy: A Quantitative Study Using Carotid Magnetic Resonance Imaging
The purpose of this study was to assess early (one year) changes in vessel wall size using CMRI. One hundred and twelve subjects with established coronary artery disease or carotid stenosis ≥15% by ultrasound with levels of apolipoprotein B ≥ 120 mg/dl were randomized to one of three intensive lipid therapies with the targeted LDL-C levels ≤80 mg/dl with and without HDL-C increase. They received carotid MRI scans at baseline and at one year after randomization. The subjects were divided into two groups based on the mean wall thickness at baseline:
diseased group (n=81) had a mean wall thickness ≥1mm by MRI and
normal group (n=25) had a mean wall thickness <1mm.
Mean wall area (MWA) in mm2 and normalized wall index (NWI = wall area/[lumen area + wall area]) were measured by trained reviewers using published criteria. The differences in MWA and NWI between baseline and one-year follow-up were compared using paired t-test. Mean changes over time were expressed as relative changes for wall size, and were compared to zero using the one-sample t-test. Six cases were excluded because of poor image quality, leaving 106 cases for analysis. In the diseased group, a statistically significant reduction in mean wall area and normalized wall index was observed after one year of treatment compared to baseline (Table I⇓). No statistically significant changes in mean wall area or normalized wall index were observed in the normal group (Table I⇓). MRI is capable of detecting vessel wall changes following one year of intensive lipid therapy in arteries with ≥ 1 mm mean wall thickness on baseline MRI. MWA and NWI regressed significantly in subjects with increased baseline wall thickness. No progression was detected in subjects with normal baseline wall thickness. These findings may have implications in the design of future clinical trials with MRI.