Prevalence of hypoechoic carotid plaques in coronary artery disease: relationship with coexistent peripheral arterial disease and leukocyte number.

In coronary artery disease (CAD), a concomitant peripheral arterial disease (PAD) entails a more severe coronary atherosclerosis. We hypothesized that the severity of carotid artery disease is greater in CAD+PAD than in CAD alone. In 90 CAD and 79 CAD+PAD patients, carotid plaque echolucency was measured by gray-scale median (GSM), and the degree of carotid stenosis by routine Doppler criteria. Plaques were absent in 20 (22.2%) CAD and 8 (10.1%) CAD+PAD patients (p=0.035), while the prevalence of carotid stenosis>or=50% was 16.7% and 25.3%, respectively (p=0.166). The GSM score was 45.1 [21.7-67.7] in CAD+PAD vs 60.1 [44.9-83.1] in CAD alone (p<0.001). Consistently, hypoechoic plaques (GSM<25th percentile) were more common in CAD+PAD than in CAD patients (38.0% vs 11.4%, p<0.001). On multivariate analysis, CAD+PAD was the only variable significantly associated with hypoechoic plaques (OR=4.16, 95% CI 1.68-10.28). However, when the leukocyte count was added to the model, it showed the strongest association with hypoechoic plaques (OR=6.70, 95% CI 2.13-21.10). In conclusion, compared with CAD alone patients, those with concomitant PAD showed a greater prevalence of plaques with characteristics of instability. Thus, our data suggest that in CAD+PAD, evaluation of carotid plaque echogenicity could contribute to improve clinical decision-making and differentiate treatments for individual patients.