Therapeutic change of HMG-CoA reductase inhibitors in patients with coronary artery disease

Study Objective. To evaluate short-term outcomes when atorvastatin was subs tituted for pravastatin or simvastatin in patients with coronary artery dis ease. Design. Open-label, fixed-dosage, one-way crossover from pravastatin and si mvastatin to atorvastatin. Setting. University-affiliated hospital and outpatient clinics. Patients. Eighty patients with coronary artery disease with a minimum basel ine low-density lipoprotein (LDL) above 130 mg/dl: 20 were treated with pra vastatin 20 mg/day, 20 with pravastatin 40 mg/day, 20 with simvastatin 20 m g/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 determ ined and were questioned about side effects of pravastatin and simvastatin. All patients were switched to atorvastatin 10 mg/day. After 12 weeks of at orvastatin therapy, a repeat fasting lipid profile was obtained and patient s were questioned about side effects with the drug. Measurements and Main Results. Baseline demographic and clinical characteri stics of the treatment groups were not significantly different with the exc eption 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/d l; 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 m g/day, 22%; pravastatin 40 mg/day, 32%; simvastatin 20 mg/day, 33%; and sim vastatin 40 mg/day, 38%. Patients achieving LDL goal with initial therapy w ere as follows: pravastatin 20 mg/day, 5%; pravastatin 40 mg/day, 5%; simva statin 20 mg/day, 20%; and simvastatin 40 mg/day 30%. After the switch to a torvastatin 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 achiev ing LDL goals with atorvastatin 10 mg/day were as follows: pravastatin 20 m g/day 60%; pravastatin 40 mg/day 30%; simvastatin 20 mg/day, 25%; and simva statin 40 mg/day, 30%. The frequency of side effects was similar for all th ree statins. Based on annual average wholesale price, atorvastatin 10 mg/da y 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 co st savings and significant reductions in LDL. The change from simvastatin 4 0 mg/day to atorvastatin 10 mg/day was associated with cost savings and an equivalent reduction in LDL.