Low rate of treatment of hypercholesterolemia by cardiologists in patients with suspected and proven coronary artery disease. BACKGROUND. Although specific guidelines for the treatment of hypercholesterolemia have been published, it is not known whether physicians treating patients likely to have lipid disorders have adopted the recommendations. METHODS AND RESULTS. The approach of cardiologists to the treatment of hypercholesterolemia in a metropolitan teaching hospital was assessed by interviewing patients with chest pain who were admitted for coronary angiography in 1988-1989 and by measuring fasting blood lipid profiles. At 1 month and again 12-24 months later, patients were contacted by telephone to determine if there had been any changes in treatment. Of 95 patients evaluated, 81 had coronary artery disease. Only 17% of those with high levels of total cholesterol and/or low density lipoprotein cholesterol were being actively treated with diet and/or drugs. In the remaining patients, either lipid studies had not been done or abnormal results had not been addressed. There was little change in treatment approach during the month after the diagnostic procedure. Furthermore, the experience was similar in those patients subjected to coronary revascularization. One to 2 years after the initial intervention, 69 of the original study group could be contacted again. Although active dietary or pharmacological therapy was initiated in some individuals during this interval, it was stopped in others. Thirty-five percent of hypercholesterolemic patients were receiving targeted therapy. CONCLUSIONS. Thus, only a small proportion of patients with documented coronary artery disease and hypercholesterolemia were being actively treated for their lipid disorder, suggesting that the published treatment guidelines have not yet been fully accepted. However, an encouraging improvement in frequency of treatment of hypercholesterolemia was documented during the 1-2-year observation period. 