CAROTID INTIMA MEDIA THICKNESS (IMT) AND IMT-PROGRESSION AS PREDICTORS OF VASCULAR EVENTS IN A HIGH RISK EUROPEAN POPULATION : THE IMPROVE STUDY

The intima-media thickness (IMT) of extracranial carotid arteries, assessed by ultrasound techniques, has been shown to be associated with most vascular risk factors for atherosclerosis and with the prevalence and extent of cardiovascular disease and coronary atherosclerosis. On this basis, this ultrasonic variable has been proposed as a surrogate index of atherosclerosis of other vascular regions. Studies have supported this hypothesis showing that IMT is a good predictor of new myocardial infarction and stroke. However, limited information has been provided on the relationship between IMT-progression, that is the real end point used in pharmacological studies, and cardiovascular events. Generally, attempts to delay IMT-progression using "anti-atherosclerotic" agents have provided encouraging results. However, no one of the studies so far published has been able to address, on a prospective basis, whether IMT-progression may effectively reflect the efficacy of the treatment in reducing the rate of cardiovascular events. To address these issues we designed “the IMPROVE study”, a currently on going prospective multicenter, longitudinal, long-term, observational study funded by the European community. The major objective of the IMPROVE study is to evaluate the association between IMT, IMT-progression and the rate of new vascular events in subjects at high risk of atherosclerosis. The effect of gene polymorphisms, lipid peroxidation, socio-economic and psychological variables on the same ultrasonic end points will be also evaluated. In order to achieve the project objectives, 3600 patients will be recruited in 7 European countries and followed ultrasonically and clinically for 30 months. Clinical events will be monitored up to 36 months. Data will be analysed with conventional statistics and with innovative approaches based on artificial neural networks. The study is considered as positive if a difference of at least 3% in the cumulative incidence of acute vascular events between the lowest and the highest quintiles of IMT or IMT-progression is detected. A summary of aims and design of the study will be presented.