Efficacy and Safety of Adding Ezetimibe to Statin Therapy Among Women and Men: Insight From IMPROVE‐IT (Improved Reduction of Outcomes: Vytorin Efficacy International Trial)

Background IMPROVE‐IT (Improved Reduction of Outcomes: Vytorin Efficacy International Trial) showed that adding the nonstatin ezetimibe to statin therapy further reduced cardiovascular events in patients after an acute coronary syndrome. In a prespecified analysis, we explore results stratified by sex. Methods and Results In IMPROVE‐IT, patients with acute coronary syndrome and low‐density lipoprotein cholesterol of 50 to 125 mg/dL were randomized to placebo/simvastatin 40 mg or ezetimibe/simvastatin 10/40 mg. They were followed up for a median of 6 years for the primary composite of cardiovascular death, myocardial infarction, hospitalization for unstable angina, coronary revascularization ≥30 days, and stroke. Among 18 144 patients in IMPROVE‐IT, 4416 (24%) were women. At 12 months, the addition of ezetimibe to simvastatin significantly reduced low‐density lipoprotein cholesterol from baseline compared with simvastatin monotherapy in men and women equally (absolute reduction, 16.7 mg/dL in men and 16.4 mg/dL in women). Women receiving ezetimibe/simvastatin had a 12% risk reduction over those receiving placebo/simvastatin for the primary composite end point (hazard ratio, 0.88; 95% confidence interval, 0.79–0.99) compared with a 5% reduction for men (hazard ratio, 0.95; 95% confidence interval, 0.90–1.01; P=0.26 for interaction). When the total number of primary events was considered, women had an 18% reduction with the addition of ezetimibe (relative risk, 95% confidence interval, 0.81; 0.71–0.94) and men had a 6% reduction (relative risk, 0.94; 95% confidence interval, 0.87–1.02; P=0.08 for interaction). The addition of ezetimibe did not increase the rates of safety events in either women or men. Conclusions IMPROVE‐IT demonstrated that the benefit of adding ezetimibe to statin is present in both women and men, with a good safety profile supporting the use of intensive, combination, lipid‐lowering therapy to optimize cardiovascular outcomes. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT00202878.