Identifying patients at risk for coronary heart disease: implications from trials of lipid-lowering drug therapy

Abnormal lipid levels contribute significantly to the risk of coronary heart disease (CHD), which is increased further in the presence of other risk factors. The association between elevated low-density lipoprotein (LDL) cholesterol and CHD risk is well established, and large primary and secondary prevention studies of HMG-CoA reductase inhibitors (statins) have shown conclusively that lowering LDL cholesterol levels reduces CHD events and total mortality. Regardless of the intervention used (diet, surgery, drugs), reduction of plasma cholesterol has consistently produced a reduction in cardiovascular risk. Absolute benefit is greatest in those who are at highest risk initially, and trial results suggest that the lower the LDL cholesterol level achieved, at least down to LDL of 3.0 mmol/l, then the lower is the CHD event risk. Epidemiological data also point to the negative impact of other lipids on CHD risk. Low levels of high-density lipoprotein (HDL) and high levels of triglycerides (particularly in conjunction with an LDL/HDL ratio >5) are particularly strong risk factors for CHD. Thus, although prevention trials to date have primarily assessed the impact of LDL lowering on CHD events, the initial assessment of CHD risk should consider a more detailed atherogenic profile including HDL and triglyceride levels. A general approach to preventing cardiovascular disease should include strategies to reduce the overall CHD risk by lifestyle modification and management of modifiable risk factors such as smoking, hypertension and diabetes. Based on data from recent prevention studies, and because they are the most potent lipid-lowering agents available for lowering LDL cholesterol, statins have appropriately become the drug of choice for most patients with hyperlipidaemia who require drug therapy.