How to use arterial imaging in primary prevention setting

The assessment of conventional vascular risk factors (VRFs) for atherosclerosis, such as hyperlipidemia, hypertension and diabetes, represents only a first step for the identification of patients in primary prevention at high risk of cardiovascular diseases. The fact that conventional VRFs predict only 60-65% of cardiac risk, and that cardiac events occur also in individuals free of established VRFs, strongly highlights the need to refer patients exposed to VRFs to additional diagnostic procedures, preferably non-invasive, enabling a better identification of persons who could benefit from dietary and/or pharmacological preventive interventions. One of the most interesting approaches proposed to increase the diagnostic and prognostic capabilities of biological markers is to integrate them with information of subclinical atherosclerosis derived from non-invasive imaging diagnostic techniques. Among these, the B-mode ultrasound of carotid arteries, and in particular the assessment of carotid artery intima media thickness (IMT), can be certainly considered as one of the most promising techniques. Almost 30 years of epidemiological, clinical and experimental researches have clearly shown that carotid IMT is a useful marker of carotid and coronary atherosclerosis. This variable correlates well with VRFs and with angiography or IVUS detected coronary atherosclerosis, discriminates well between patients with and without a history of vascular disease and increases significantly the capacity of VRFs to identify patients at risk of vascular events. Carotid B-mode ultrasound was recently used also to demonstrate a gradual, consistent and independent association between IMT and the incidence of new coronary and cerebrovascular events. Carotid artery IMT measurement has, therefore, a great potential to be included, in short, within the diagnostic arsenal to be used in clinical practice a) to determine the individual cardiovascular risk, b) to personalize the therapies available and c) to evaluate the effectiveness of therapeutic strategies undertaken. An efficient pre-selection of patients at high cardiovascular risk may also be helpful in reducing the number of subjects to be treated to prevent a single vascular event (NNT), thus reducing the cost-benefit ratio of programs of primary prevention.