Carotid ultrasound: is it the best way to evaluate subclinical atherosclerosis?

Carotid artery ultrasound is a simple, safe, non-invasive and cost-effective method to assess the presence or absence of carotid plaques and measure their extent. Measurement of intimal medial thickness (IMT) is the most widely used marker to quantify the burden of atherosclerotic disease at that level. All guidelines published to date are against routine population screening. Most guidelines recommend screening patients with multiple risk factors including diabetes, age > 65 years, smoking, or hypercholesterolemia. IMT measurements are extremely heterogeneous due to interindividual variability and some technical measurement concerns. Furthermore, increased IMT is also the result of non-atherosclerotic processes, such as smooth muscle cell hyperplasia and fibrocellular hypertrophy leading to medial hypertrophy and compensatory arterial remodeling. Nowadays, other ultrasound measurements such as the highest maximal wall thickness or the average maximal wall thickness have been studied and used to predict atherosclerotic burden other than IMT. This narrative review aims to examine the role of carotid ultrasound in the evaluation of patients with sub-clinical atherosclerosis and cardiovascular disease primary prevention.