Impact of dyslipidaemia. Lessons from clinical trials

Coronary heart disease (CHD) is a major cause of morbidity and mortality in Western countries, and is associated with significant healthcare costs. Epidemiological studies have shown that elevated cholesterol levels, particularly elevated low density lipoprotein (LDL) cholesterol, are a major established risk factor for the development of CHD. There is a large amount of clinical data available to indicate that lowering total or LDL-cholesterol levels reduces the risk of cardiovascular events and mortality. The most recent cholesterol treatment guidelines from the US and Europe recommend intensive treatment (usually pharmacological) for patients at highest risk for CHD. Results from a number of landmark primary and secondary prevention studies are in support of these guidelines and also suggest that the lower the level of LDL-cholesterol achieved with treatment, the better clinical benefit attained. Thus, these findings indicate that even more aggressive lipid lowering than that recommended by available treatment guidelines may be warranted. Finding and treating all individuals at risk for CHD would be expected to increase the overall treatment costs of hypercholesterolaemia because many patients may not otherwise be treated; however, targeting high risk patients, rather than treating all patients or treating inappropriately, would be expected to reduce other healthcare costs and the indirect costs of lost productivity due to cardiovascular morbidity and mortality. Studies with the HMG-CoA reductase inhibitors, which show that these drugs substantially lower LDL-cholesterol, are the most convincing since they have consistently shown reductions in cardiovascular morbidity and mortality. As a result, statins are now well-established agents for the treatment of dyslipidaemia.