With the aim of assessing the effectiveness and safety of lovastatin in patients with hypercholesterolemia after heart transplantation, as well as the potential differences in the lipid-lowering effect of lovastatin between patients with or without pretransplant coronary artery disease (CAD), we studied 63 heart transplant patients who had serum total cholesterol > 250 mg/dl in spite of dietary therapy. Mean age of subjects was 47 +/- 2 years. Triple-drug immunosuppressive therapy consisted of cyclosporine, azathioprine, and steroids. Thirty-nine patients (62%) had pretransplant CAD and 24 (38%) did not. Pretreatment serum lipid levels were: total cholesterol, 302 +/- 32 mg/dl; low-density lipoprotein (LDL) cholesterol, 201 +/- 35 mg/dl; high-density lipoprotein (HDL) cholesterol, 60 +/- 19 mg/dl; triglycerides, 205 +/- 86 mg/dl; and total/HDL cholesterol ratio, 5.4 +/- 1.6. Patients received 10 to 40 mg/day of lovastatin (mean dose 17 +/- 6) for 13 +/- 4 months. There were no serious adverse events. At 3 months, lovastatin decreased total cholesterol by 15% (p < 0.001), LDL cholesterol by 21% (p < 0.001), triglycerides by 17% (p < 0.05), and total/HDL cholesterol ratio by 17% (p < 0.001), and increased HDL cholesterol by 3% (NS). Although lovastatin was effective in both patients with pretransplant CAD and non-CAD, analysis of its effect in each subgroup (CAD and non-CAD) revealed that its lipid-lowering effect was higher for non-CAD patients (-20% vs -12% for total cholesterol, and -27% vs -17% for LDL cholesterol, both p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)