Diverging risk factors exist for cardiovascular disease

Longitudinal studies, such as the Seven Country and Framingham studies identified major risk factors for cardiovascular disease (CVD): smoking and a rich diet, with consequent high levels of total cholesterol and high blood pressure. Differences in the prevalence of these risk factors among participating countries have been ascertained to be responsible for differences in the incidence of stroke and IHD (Keys et al., 1980; Keys et al., 1981; Mariotti et al., 1982). For more detailed information about the prevalence, causes and consequences of (high) blood pressure, see the EUphact Blood Pressure.

Other studies have contributed to the knowledge of CVD risk factors and demonstrate that low socio-economic status, physical inactivity, obesity and diabetes are also associated with an increased CVD risk (Marmot et al., 1978a; Marmot et al., 1978b; Morris et al., 1980; Barrett-Connor et al., 1991).

More recently, a standardized case-control study of acute myocardial infarction conducted in 52 countries has demonstrated that abnormal lipids, smoking, hypertension, diabetes, abdominal obesity, psychosocial factors, unfavourable patterns of fruit, vegetable and alcohol consumption and of physical activity account for most of the risk of myocardial infarction worldwide. See Association of risk factors with acute myocardial infarction .

Finally there are other factors such as infections, personal factors such as the ability to cope with stress (Rosengren et al., 2004) and exposure to air polluting particles (Hoek et al., 2002, Brook et al., 2004) that can play a role. More detailed research is needed to identify the precise contribution of these individual factors.

Alongside these observational studies that have demonstrated the predictive role of risk factors, there are other studies, which have highlighted the risk reversibility (reducing disease incidence by reducing the risk factors) and the substantial decrease of CVD and other chronic degenerative diseases through preventive action at both individual and population levels (Puska et al., 1995).

Although priorities can differ between geographic regions because of variations in the prevalence of risk factors, disease occurrence and socio-economic status, the effective prevention of well-known risk factors has the potential to prevent most premature cases of myocardial infarction.

In recent years, an important conceptual advance has been introduced. The focus is now no longer exclusively on adverse effects of risk factors, but also on protective effects of favourable levels of all readily measured modifiable major risk factors. Low-risk persons are rare in the general population and therefore research on the impact of low risk requires following large cohorts on a long-term basis. Available data indicate that for low risk subgroups, CVD, and particularly IHD, is rare and endemic, not epidemic, throughout adulthood (Palmieri et al., 2006).

Quantitative risk assessment is possible

The global absolute cardiovascular risk is the best way to assess cardiovascular risk in persons who have no recognized clinical manifestations of atherosclerotic disease. The use of this indicator takes into account the multifactorial aetiology of CVD. Knowing some risk factors (sex, age, cholesterol, systolic blood pressure, smoking) it is possible to estimate the probability to experience a major cardiovascular event in the following ten years. Furthermore, the global absolute CVD risk makes the assessment objective, accurate and comparable over time.

To carry out this risk assessment, the 2007 European Guidelines on CVD Prevention (Fourth Joint Task Force, 2007) used the SCORE system (Conroy et al., 2003). See The SCORE risk chart as an example.