title: Impact of switching treatment from rosuvastatin to atorvastatin on rates of cardiovascular events.
abstract: BACKGROUND
  Now that generic atorvastatin has become available, a process of switching from rosuvastatin to atorvastatin may occur and could persist until the patent on branded rosuvastatin expires. It is important to understand the impact that such therapy may have on patients' cardiovascular (CV) health.
  
  
  OBJECTIVE
  This simulated study estimates the impact of switching patients treated with rosuvastatin to atorvastatin on rates of CV events over a 5-year period.
  
  
  METHODS
  A study of 50,038 virtual dyslipidemic patients aged 45 to 70 years was conducted using the Archimedes model. Virtual patients were created based on the profiles of patients in the National Health and Nutrition Examination Survey (NHANES). Statin treatment models were constructed based on data from published studies, including STELLAR, JUPITER, CARDS, ASCOT, and TNT. Patients were started on a dose of rosuvastatin based on their ATP III low-density lipoprotein cholesterol (LDL-C) goal and the distributions of statin use observed in US pharmacy claims data. Patients were monitored for 5 years, during which time they received regular visits with the opportunity to increase their dosage if they were above their LDL-C goal. In the experimental arm, patients were switched from rosuvastatin to atorvastatin at the first clinic visit 6 weeks after initiating rosuvastatin (using an atorvastatin dose twice the rosuvastatin milligram-dose). No switching occurred in the control arm, and patients were titrated as necessary per ATP III cholesterol management guidelines. The rate of first occurrence of a major adverse cardiovascular event (MACE; myocardial infarction, stroke, and/or cardiovascular-related death) over the 5-year period was estimated for each study arm.
  
  
  RESULTS
  After 5 years, in the atorvastatin-switched arm compared with continuing rosuvastatin, 4.8% fewer patients reached goal (87% vs 91%, respectively). The 5-year relative risk for MACE with switching was 1.109 (95% CI, 1.092-1.127), and the number needed to harm (NNH) to incur 1 additional MACE over 5 years was 262, favoring treatment with rosuvastatin. In diabetic individuals who were switched to atorvastatin, the 5-year relative risk for MACE was 1.121 (95% CI, 1.091-1.151), and the NNH over 5 years was 195, indicating greater risk in diabetic individuals. The results were insensitive to adherence rates and LDL-C goal values.
  
  
  CONCLUSIONS
  This study found that switching from rosuvastatin to atorvastatin led to fewer patients attaining LDL-C goal and a greater risk for MACE.
authors.affiliation: Archimedes, Inc, San Francisco, California. Electronic address: henri.folse@archimedesmodel.com.
authors.forename: Henry
authors.initials: H
authors.lastname: Folse
authors.affiliation: AstraZeneca, Mölndal, Sweden.
authors.forename: Catarina
authors.initials: C
authors.lastname: Sternhufvud
authors.affiliation: Archimedes, Inc, San Francisco, California.
authors.forename: C
authors.initials: C
authors.lastname: Andy Schuetz
authors.affiliation: Archimedes, Inc, San Francisco, California.
authors.forename: Badri
authors.initials: B
authors.lastname: Rengarajan
authors.affiliation: AstraZeneca Pharmaceuticals LP, Wilmington, Delaware.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Gandhi
mesh_terms: D000368:Aged; D000069059:Atorvastatin; D002318:Cardiovascular Diseases / Q000139:chemically induced* / Q000453:epidemiology; D003198:Computer Simulation; D057915:Drug Substitution / Q000009:adverse effects*; D050171:Dyslipidemias / Q000188:drug therapy*; D005464:Fluorobenzenes / Q000493:pharmacokinetics / Q000627:therapeutic use*; D006538:Heptanoic Acids / Q000009:adverse effects* / Q000493:pharmacokinetics / Q000627:therapeutic use; D006801:Humans; D008875:Middle Aged; D008954:Models, Biological; D011743:Pyrimidines / Q000493:pharmacokinetics / Q000627:therapeutic use*; D011758:Pyrroles / Q000009:adverse effects* / Q000493:pharmacokinetics / Q000627:therapeutic use; D012307:Risk Factors; D000068718:Rosuvastatin Calcium; D013449:Sulfonamides / Q000493:pharmacokinetics / Q000627:therapeutic use*
chemical_list: D005464:Fluorobenzenes; D006538:Heptanoic Acids; D011743:Pyrimidines; D011758:Pyrroles; D013449:Sulfonamides; D000068718:Rosuvastatin Calcium; D000069059:Atorvastatin
keywords: atorvastatin; cholesterol; model; rosuvastatin; simulation; statin