Efficacy of combination therapy with ezetimibe and statins versus a double dose of statin monotherapy in participants with hypercholesterolemia: a meta-analysis of literature

Background The aim of this study was to compare and summarize the lipid-altering effects of combination therapy with ezetimibe and statins (E/S) and a double dose of statin (D/S) monotherapy on patients with hypercholesterolemia. Methods We conducted search on 2 medical databases, PubMed and EMBASE to identify all relevant studies. A meta-analysis was performed to clarify the efficacy in the two groups. Only double-blind Randomized controlled study (RCTs) of efficacy evaluation in the two groups with ezetimibe and statins and a double dose of statin in participants with hypercholesterolemia that examined low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC) and high-density lipoprotein (HDL) were included. Two reviewers extracted data from all primary studies independently. The primary data were the level of LDL-C, TC and HDL-C concentrations at the end point and are expressed as mean and standard deviation (SD). Results A total of 11 double-blind, active or placebo-controlled studies with 1926 hypercholesterolemia adults randomized to ezetimibe 10 mg added to ongoing statins (N = 994) or statin titration (doubling) (N = 932) were pooled for the global meta-analysis. The effect size between treatment groups within individual studies was assessed by weighted mean difference (MD) using a random- or fixed-effect model. The result showed that the participants in E/S group get obvious lower LDL-C [MD = -13.14 mg/dL, 95%CI (-16.83, -9.44), p = 0.00001] and TC concentration [MD = -23.79 mg/dL, 95%CI (-38.65, -8.93), p = 0.002] from baseline to follow-up, comparing to the D/S group. Besides, no significant between-group differences were observed for concentrations of HDL-C [MD = 0.46 mg/dL, 95%CI (- 1.14, 2.06), p = 0.57]. According to subgroup analysis, the combination of ezetimibe and atorvastatin (10 mg) [MD = -16.98 mg/dL, p < 0 .0001] or simvastatin (20 mg) [MD = -17.35 mg/dL, p < 0 .0001] showed stronger ability of reducing LDL-C than combination of ezetimibe and rosuvastatin (10 mg) [MD = -9.29 mg/dL, p = 0.05]. The efficacy of short-term (endpoint time between 6 to 16 week) and long-term (52 week) treatment in the LDL-C between two groups did not show significant differences. Besides, only participants from Asia treated with combination therapy were associated with a significant lower LDL-C concentration [MD = -14.7 mg/dL, p < 0 .0001]. Conclusions The addition of ezetimibe to statin appears to be more effective on reducing LDL-C and TC concentrations than doubling the statin dose. Moreover, the ability to reduce cholesterol levels of combinations therapy with ezetimibe and different statins or to participants from different geographic location may vary, based on this meta-analysis, while more samples are needed to verify.