無症候性患者の一次予防評価における高リスク冠動脈プラークと頸動脈エコー検査所見

Subclinical coronary atherosclerosis is common but its biological aggressiveness and interplay with extracoronary disease in asymptomatic individuals remain unclear. We evaluated the prevalence of high-risk coronary plaques (HRPs) and their relationship with mild carotid atherosclerosis and coronary calcium in a cardiovascular (CV) high-risk cohort in primary prevention. This retrospective multicenter study enrolled 269 asymptomatic adults with multiple CV risk factors who underwent Coronary Computed Tomography Angiography (CCTA) after prior carotid duplex ultrasound (CDUS). Coronary artery disease (CAD) was graded as absent, non-obstructive (<50% stenosis) or obstructive (≥50%), and HRPs were identified by ≥1 adverse morphological feature (low attenuation, positive remodeling, napkin-ring sign, spotty calcification). Carotid disease was classified as CDUS 0 (no plaque), CDUS 1-49% (mild), or CDUS ≥ 50% (significant). Pre-specified analyses explored prevalence of HRPs across CDUS-calcium-score strata (cut-off 100 Agatston) and independent predictors within the CDUS 1-49% subgroup. CAD was absent in 31%, non-obstructive in 41%, and obstructive in 28%. HRPs were present in 30.9% of all cases, in 26.6% of non-obstructive and in 64.6% of obstructive CAD. HRPs prevalence rose step-wise from 10.0% (CDUS 0 + Ca < 100) to 27.7% (CDUS 1-49% + Ca < 100), 41.2% (CDUS 0 + Ca ≥ 100) and 59.4% (CDUS 1-49% + Ca ≥ 100). In patients with CDUS 1-49%, current smoking independently predicted HRPs (OR 2.1, 95% CI 1.0-4.5; p = 0.049). Nearly one-third of asymptomatic adults with high CV risk already showed HRPs. Mild carotid atherosclerosis synergized with a calcium score ≥ 100 to identify a subgroup in which six of ten individuals exhibited HRPs. Smoking was the only independent clinical correlate identified of plaque vulnerability. Combined carotid ultrasound, calcium scoring and CCTA may substantially refine primary prevention risk stratification beyond traditional factors.