Therapeutic Change of HMG‐CoA Reductase Inhibitors in Patients with Coronary Artery Disease

Abstract

STUDY OBJECTIVE: To evaluate short-term outcomes when atorvastatin was substituted for pravastatin or simvastatin in patients with coronary artery disease. DESIGN: Open-label, fixed-dosage, one-way crossover from pravastatin and simvastatin to atorvastatin. SETTING: University-affiliated hospital and outpatient clinics. PATIENTS: Eighty patients with coronary artery disease with a minimum baseline low-density lipoprotein (LDL) above 130 mg/dl: 20 were treated with pravastatin 20 mg/day, 20 with pravastatin 40 mg/day, 20 with simvastatin 20 mg/day, and 20 with simvastatin 40 mg/day for a minimum of 6 months, with a prescription refill rate of 80% or greater. Intervention. Before crossover, patients had a fasting lipid profile determined and were questioned about side effects of pravastatin and simvastatin. All patients were switched to atorvastatin 10 mg/day. After 12 weeks of atorvastatin therapy, a repeat fasting lipid profile was obtained and patients were questioned about side effects with the drug. MEASUREMENTS AND MAIN RESULTS: Baseline demographic and clinical characteristics of the treatment groups were not significantly different with the exception of a lower baseline LDL in patients receiving pravastatin 20 mg/day. Baseline LDL values were as follows: pravastatin 20 mg/day, 158+/-26 mg/dl; pravastatin 40 mg/day, 176+/-22 mg/dl; simvastatin 20 mg/day, 177+/-27 mg/dl; and simvastatin 40 mg/day, 177+/-27 mg/dl. Reductions in LDL after treatment with pravastatin or simvastatin were as follows: pravastatin 20 mg/day, 22%; pravastatin 40 mg/day, 32%; simvastatin 20 mg/day, 33%; and simvastatin 40 mg/day, 38%. Patients achieving LDL goal with initial therapy were as follows: pravastatin 20 mg/day, 5%; pravastatin 40 mg/day, 5%; simvastatin 20 mg/day, 20%; and simvastatin 40 mg/day, 30%. After the switch to atorvastatin 10 mg/day, reductions in LDL were as follows: pravastatin 20 mg/day, 39% (p<0.001); pravastatin 40 mg/day, 38% (p<0.01); simvastatin 20 mg/day, 39% (p=0.04); and simvastatin 40 mg/day, 38% (p=0.83). Patients achieving LDL goals with atorvastatin 10 mg/day were as follows: pravastatin 20 mg/day, 60%; pravastatin 40 mg/day, 30%; simvastatin 20 mg/day, 25%; and simvastatin 40 mg/day, 30%. The frequency of side effects was similar for all three statins. Based on annual average wholesale price, atorvastatin 10 mg/day was more cost-effective than all pravastatin and simvastatin regimens. CONCLUSIONS: Therapeutic interchange from pravastatin 20 and 40 mg/day and simvastatin 20 mg/day to atorvastatin 10 mg/day was associated with both cost savings and significant reductions in LDL. The change from simvastatin 40 mg/day to atorvastatin 10 mg/day was associated with cost savings and an equivalent reduction in LDL.