Definition of high risk individuals to optimise strategies for primary prevention of cardiovascular diseases

The identification of high risk individuals is one of the main goals of cardiovascular primary prevention and constitutes the basis for implementing actions oriented toward reducing modifiable risk factors at individual level, from changing life styles to drug interventions. The most appropriate method for identifying high risk individuals is the evaluation of their absolute global risk, a probability indicator of incidence, predictable on the basis of risk factor levels. Risk functions, derived from longitudinal studies, are used to identify persons at high probability to develop cardiovascular diseases. The appropriateness of the use of these risk functions depends upon the characteristics of the population that generated them and of individuals which they are applied to. Risk charts are simply absolute global risks calculated by classes of risk factors; risk scores are more precise evaluation derived from absolute global risks calculated by continuous levels of risk factors. Risk charts and scores are formed through the risk functions derived from different studies: Framingham, PROCAM (Munster), Seven Countries Study, SCORE and Progetto CUORE. A further chart has been created using the Framingham Study and adapted to the guidelines of New Zealand regarding the treatment of dyslipidemias and blood pressure. Major differences can be found in the availability of risk factors in men and women and in the use of fatal and non-fatal coronary and cerebrovascular events as end-points. All these studies use different diagnostic criteria for identification, classification and validation of events. The awareness of the risk charts differences is a key issue to refine tools for prevention of cardiovascular disease in populations with different probabilities of disease frequency.