Introduction: To date, most clinical comparisons of ezetimibe-statin combination therapy versus statin monotherapy have relied entirely on surrogate variables. In this systematic review, we study the efficacy and safety of ezetimibe-statin combination therapy in comparison to statin monotherapy in terms of the prevention of cardiovascular events in hyperlipidemic patients with atherosclerosis and/or diabetes mellitus.
Method: This review is based on a systematic literature search (1995 to July 2015) in PubMed, the Excerpta Medica Database (EMBASE), the Cochrane Library, and the ClinicalTrials.gov registry.
Results: Nine randomized, controlled trials with data from a total of 19 461 patients were included. Ezetimibe-statin combination therapy was associated with a lower risk of cardiovascular events than statin monotherapy: 33% of the patients treated with ezetimibe and a statin, and 35% of those treated with a statin alone, had a cardiovascular event within seven years (number needed to treat [NNT]: 50 over 7 years). Combination therapy was also significantly more effective in preventing a composite endpoint consisting of death due to cardiovascular disease, nonfatal myocardial infarction, unstable angina pectoris, coronary revascularization, and nonfatal stroke (hazard ratio [HR] 0.94, 95% confidence interval [0,89; 0,99]; p = 0.016). Diabetic patients benefited from combination therapy rather than monotherapy with respect to cardiovascular morbidity (HR 0.87 [0.78; 0.94]). On the other hand, the addition of ezetimibe to statin therapy did not lessen either cardiovascular or overall mortality. Serious undesired events occurred in 38% of the patients taking ezetimibe and a statin and in 39% of the patients taking a statin alone (relative risk 1.09 [0.77; 1.55]).
Conclusion: In high-risk patients with an acute coronary syndrome, combination therapy with ezetimibe and a statin lowered the risk of cardiovascular events in comparison to statin monotherapy. The risk of dying or suffering an adverse drug effect was similar in the two treatment groups.