Ecogenicità della placca aterosclerotica femorale e rischio cardiovascolare nell'arteriopatia obliterante degli arti inferiori

Abstract

Aims. Atherosclerosis is a systemic disease and the presence of an unstable atherosclerotic plaque in a vascular district, characterized by low echogenicity at B-mode ultrasound, leads to a greater prevalence of unstable plaques in other vascular beds. Peripheral arterial disease (PAD) is a common manifestation of atherosclerosis associated with a high risk of developing cardiovascular events. The objective of the present study is to evaluate the prognostic impact of femoral plaque echogenicity in PAD. Methods and Results. Femoral plaque echogenicity of 246 claudicants with ankle/brachial index<0.90 was evaluated at B-mode ultrasound by visual analysis and by calculating the Gray Scale Median (GSM) value. Plaques were classified as hypoechoic at visual analysis if echogenicity involved <50% of the plaque area. The occurrence of major cardiovascular events, including myocardial infarction and stroke, was prospectively assessed. During a median follow-up of 30 months, 32 patients (13%) had a cardiovascular event. The femoral GSM showed an inverse relationship with cardiovascular risk, also after adjustment for possible confounders (HR=0.97,95% CI 0.95-0.98, p<0.001) (the higher the echogenicity, the lower the cardiovascular risk). Spearman analysis showed that femoral GSM values and plaque types assessed by visual analysis were highly correlated (ρ=0.905,p<0.001). Consistently, at Cox analysis, patients with hypoechoic femoral plaque at visual analysis had a 7.9-fold increased cardiovascular risk compared to patients with hyperechoic plaque after adjustment for possible confounders (95% CI 3.42-18.03,p<0.001). Conclusions. The presence of an hypoechoic atherosclerotic femoral plaque, evaluated by noninvasiveB-mode ultrasound, entails a higher cardiovascular risk in PAD.