Carotid intima media thickness (IMT) and IMT-progression as predictors of vascular events in a high risk european population: the Improve study

The IMT of carotid arteries, assessed by B-mode ultrasound, is associated with atherosclerosis risk factors and with the prevalence and extent of coronary atherosclerosis. In addition IMT is a good predictor of new myocardial infarction and stroke. On this basis, IMT has been proposed as a surrogate index of atherosclerosis of other vascular regions. Little is known, however, about the relationship between IMT-progression, the real end point used in pharmacological studies, and vascular events. Attempts to delay IMT-progression using "anti-atherosclerotic" agents provided encouraging results. However, no studies have been able to address, prospectively, whether IMT-progression reflects the efficacy of treatments in reducing the rate of vascular events. The IMPROVE study, a currently on going prospective multicenter, longitudinal, long-term, observational study, funded by EU, will evaluate the association between IMT, IMT-progression and the rate of new vascular events in subjects at high risk of atherosclerosis. The effect of genes’ polymorphism, lipid peroxidation, socio-economic and psychological variables will be also evaluated. 3600 patients will be recruited in 7 European countries and followed for 36 months. Data will be analysed with conventional statistics and with artificial neural networks. The study will be 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 will be detected. A summary of aims and design of the study will be presented.