Primary prevention of coronary heart disease: from controversy to consensus

In recent years, interest has tended to focus on prevention of coronary events in high-risk groups, particularly those with established coronary heart disease. While this is understandable, it has led to a lack of emphasis on primary prevention. Yet it is only by means of primary or even pri-mordial prevention that a substantial reduction in coronary mortality on a population level will be achieved. This becomes clear when we consider that half of all persons who suffer a first myocardial infarction will die within the first month thereafter. Nevertheless, major progress has been made in primary prevention. Reliable risk algorithms have been constructed in Europe (PROCAM) and the U.S., and preliminary analyses on both sides of the Atlantic indicate that these algorithms can be useful applied to populations which are geographically and ethnically distinct from those in which they were derived. A notable trend in recent years is the increasing recognition of the metabolic syndrome with its key components of abdominal obesity, hypertriglyceridemia hypertension, low HDL-C, small, dense LDL, insulin resistance and hyperinsulinemia as being perhaps the most common and dangerous metabolic abnormality of all. Newer risk markers are being evaluated. The position of homocysteine remains unclear. Despite a strong association of elevated homocysteine with risk in case-control studies, prospective investigations have been less convincing. Evidence is beginning to accumulate from cross-sectional and prospective studies that markers of inflammation such as C-reactive peptide may improve our ability to predict risk of coronary events. While these data are encouraging, results of further studies must be awaited before the true place of these markers can be determined. The same can be said of many genetic markers of risk. Though a very large number of association studies have indicated links between a variety of genetic markers and coronary risk, these effects have tended to disappear after controlling for epigenetic and confounding factors and with increasing sample sizes. Finally, much attention is being devoted to non-invasive imaging of the coronary arteries. Such methods hold much promise as a screening test to exclude coronary stenosis in low-risk individuals. However, the measurement of calcium content of the arterial wall by EBCT has yet to prove its usefulness as a predictor of coronary events.