Controversy still remains regarding the possible clinical or arteriographic benefit of intensive lipid-altering therapy in patients who have coronary artery disease and apparently normal lipid levels. Resolution of this controversy appears to depend on an improved understanding of the role of variables other than total or low density lipoprotein cholesterol levels. A comparison of the "normolipidemic" subgroup of The Familial Atherosclerosis Treatment Study patients and The Harvard Atherosclerosis Reversibility Project patients indicates that low levels of high density lipoprotein cholesterol and elevated levels of apolipoprotein B appear to increase considerably the likelihood of benefit from intensive lipid-altering therapy. Other risk-related variables such as systolic blood pressure and lipoprotein(a) further contribute to the prediction of risk and possibly to the potential for treatment benefit.