Background and Purpose
Carotid artery stenosis has been recognized as one of recurrent stroke risk factors. In the therapy for carotid artery stenosis, we have to analyze the quantity and quality of carotid plaque burden. The objective for this prospective study is to clarify duration to change plaque quality by intensive lipid lowering therapy in patients with carotid plaque. 
Materials and Methods
In 10 patients with asymptomatic cervical carotid stenosis (40-79%), proprotein convertasesubtilisin/kexin type 9 (PCSK9) inhibitors are administrated to lower low-density lipoprotein cholesterol (LDL-C) in addition to the maximum tolerable dose of statin. The serum LDL-C value and the plaque-to-muscle signal intensity ratio on a three-dimensional T1-weighted turbo-spin-echo black-blood magnetic resonance imaging (MRI) are evaluated 1, 2and 3 months later. 
Results
From August 2017 to December 2018, 10 patients were enrolled. The LDL-C value was significantly decreased from the baseline to 1 month (97.7±5.75 mg/dL, 22.5±4.27 mg/dL, respectively, p<0.001, paired t-test). The plaque-to-muscle signal intensity ratio on MRI showed a significant decrease in a month (p=0.048, paired t-test), but not from 1 to 2 months and from 2 to 3 months.
Conclusions
In the patients with carotid stenosis administrated PCSK9 inhibitor, significant qualitative change in carotid plaque on MRI was shown in one month.

ESOC-2019