Abstract 5769: Cardiovascular Outcomes for Patients Treated With Ezetimibe/Simvastatin Combination Compared With Simvastatin or Atorvastatin Alone
Purpose: The efficacy of the combination of ezetimibe and simvastatin has been questioned following the results from the ENHANCE study, which found no difference in change in carotid intima-media thickness with ezetimibe/simvastatin combination compared with simvastatin alone. Because of the limited patient population (heterozygous familial hypercholesterolemia) and failure to examine cardiovascular events, additional research is necessary to evaluate clinical outcomes for patients using ezetimibe/simvastatin. Although a controlled clinical outcomes study is currently being conducted, results are not expected until 2012.
Methods: Using administrative claims from a health insurance plan that included commercial and Medicare clients, we conducted a retrospective cohort analysis to compare the relative rates of clinical events (hospitalization for myocardial infarction (MI) or stroke) among patients age 18 to 84 with history of MI, stroke, or diabetes treated with ezetimibe/simvastatin combination versus simvastatin alone or atorvastatin alone. Simvastatin and atorvastatin-treated patients were each matched 1:1 with ezetimibe/simvastatin patients based on simvastatin daily dose equivalent and propensity score (derived using demographic and cardiovascular risk variables). Proportional hazards regression was performed with adjustment for demographics, medical history, and coronary heart disease medication use.
Results: There were 9,983 patients in each cohort. The number of events per 100 person-years was 0.89 for ezetimibe/simvasatin, 0.93 for atorvastatin, and 1.05 for simvastatin. The risk of events was not significantly different for ezetimibe/simvastatin vs. atorvastatin alone (adjusted HR 0.89; 95% CI, 0.67–1.17), for ezetimibe/simvastatin vs. simvastatin alone (adjusted HR 0.80; 95% CI, 0.61 – 1.04), or simvastatin alone vs. atorvastatin alone (adjusted HR 1.11; 95% CI, 0.86 –1.44).
Conclusions: Although the ENHANCE study raised questions on the efficacy of the ezetimibe/simvastatin combination, findings from this large population of high risk patients suggest that cardiovascular outcomes for patients treated with ezetimibe/simvastatin are similar to those treated with simvastatin or atorvastatin alone.