Cardiac risk factors
Cardiac screening is a focus of attention because cardiovascular diseases are responsible for the deaths of 16.7 million people worldwide each year (World Health Organization, 2003), but 50% of deaths and disability from cardiovascular disease (CVD) can be reduced through reduction of major coronary risk factors (World Health Organization, 2002). Population-based studies, such as the well known Framingham Heart Study, demonstrated several major risk factors to be independent predictors of coronary heart disease (CHD) although the studies were based on a mainly White population in Massachusetts, USA. Major risk factors include cigarette smoking, hypertension, high serum low-density lipoprotein cholesterol, low levels of high-density lipoprotein cholesterol, diabetes mellitus and advancing age. Data from the Framingham Heart Study form the basis of internationally used coronary prediction algorithms (Wilson et al., 1998), two dimensional risk charts (Wood et al., 1998) and a Cardiac Risk Assessor computer programme (The Framingham Risk Equation; Anderson et al., 1991) for calculating risk in patients without known existing CHD. Psychological factors are absent from risk calculation instruments, although recent reviews have detailed the role of psychological factors in manifestation of CHD (Rozanski et al., 2005).
Cardiac screening is generally based on a ‘high risk’ approach in which individuals in the general population at particularly high risk are identified for provision of advice, further diagnostic investigation, or treatment in order to reduce their risk of manifestation of CHD or CVD. A reduction of risk factors is important because people with multiple risk factors for heart disease are three to five times more likely to die, suffer a heart attack, or other major cardiovascular event than people without such conditions or risk factors (DoH, NSF, 2000).