Non-stenotic Echolucent Ultrasound-assessed Femoral Artery Plaques Are Predictive for Future Cardiovascular Events in Middle-aged Men

Objectives: The aim of the present study was to examine the relationship between plaque occurrence, plaque size and plaque echogenicity, assessed by B-mode ultrasound, in the femoral artery and the development of clinical cardiovascular disease.

Background: The relationship between carotid atherosclerosis assessed by B-mode ultrasound and cardiovascular disease has been thoroughly investigated. In comparison, the femoral arteries have received much less attention.

Methods: The femoral artery was examined by high-resolution B-mode ultrasound in 391, 58-year-old men identified by screening in the city of Goteborg, Sweden. Assessment of plaque occurrence, plaque size (no, small, or moderate/large) and plaque characteristics in terms of echogenicity (no, echogenic or echolucent) were performed.

Results: Subjects with a plaque present in the femoral artery at study baseline had a three-fold increase in odds ratio (OR 3.04, 95%, CI 1.24-7.42) for having a cardiovascular event during 6.6 years of follow-up compared to subjects without plaque. After adjustment for cardiovascular risk factors (LDL, triglycerides, systolic blood pressure and smoking) there was a borderline significant association between plaque occurrence and cardiovascular disease (OR = 2.64, p = 0.055). Plaque size could be demonstrated to be associated with cardiovascular events (p = 0.012, for trend). The results also showed that in this group of men, the risk of having a cardiovascular event was to a large extent confined to those with an echolucent plaque at baseline. However, no significant difference in risk prediction was seen between echogenic and echolucent plaques, respectively.

Conclusions: This is the first study to show that the presence of non-stenotic plaques in the femoral artery in middle-aged men without prior cardiovascular events has a predictive value for future cardiovascular events. The relationship was attenuated by adjustment for traditional cardiovascular risk factors. Data also indicates that plaque echolucency predicts increased risk.