Abstract 15286: Femoral Plaque Echogenicity and Cardiovascular Risk Prediction in Lower Extremity Peripheral Arterial Disease
Background. Atherosclerosis is a systemic disease, and the presence of an unstable atherosclerotic plaque in a certain vascular district, characterized by low echogenicity at B-mode ultrasound, is associated to a greater prevalence of unstable plaques in other vascular beds. The present study was designed to verify whether the evaluation of femoral plaque echogenicity might be useful to stratify cardiovascular risk in patients affected by lower extremity peripheral arterial disease (LE-PAD).
Methods. Femoral plaque echogenicity of 246 claudicant patients with ankle/brachial index ≤0.90 was evaluated at B-mode ultrasound by visual analysis and by calculating the Gray Scale Median (GSM) value. At visual analysis, femoral plaques were graded as: 1) echolucent (type 1), 2) predominantly echolucent (type 2), 3) predominantly echogenic (type 3), or 4) echogenic (type 4). Patients with type 1 or type 2 plaques were considered as having a hypoechoic plaque, while patients with type 3 or type 4 plaques as having a hyperechoic plaque at visual analysis. The occurrence of myocardial infarction and stroke was prospectively assessed.
Results. Femoral GSM values and plaque types assessed by visual analysis were highly correlated by Spearman analysis (ρ=0.905, p<0.001). During a median follow-up of 30 months, 32 patients (13%) had a cardiovascular event. At Cox analysis, femoral GSM showed an inverse relationship with cardiovascular risk, even after adjustment for age, sex, smoking, diabetes mellitus, hypercholesterolemia, hypertension, body mass index, previous myocardial infarction or stroke, ABI, femoral plaque thickness and percentage stenosis, and maximum carotid IMT (HR=0.96, 95% CI 0.95-0.98, p<0.001). Consistently, patients with hypoechoic femoral plaques at visual analysis had a 8.9-fold increased cardiovascular risk compared to patients with hyperechoic plaques after adjustment for the possible confounders indicated above (95% CI 3.57-22.06, p<0.001).
Conclusions. Our study suggests that the simple, non-invasive evaluation of femoral plaque echogenicity by B-mode ultrasound may help to identify vulnerable LE-PAD patients exposed to a higher cardiovascular risk who may benefit from additional diagnostic and therapeutic strategies.
- © 2011 by American Heart Association, Inc.