Comparing Simvastatin Monotherapy V/S Simvastatin-Ezetimibe Combination Therapy for the Treatment of Hyperlipidemia: A Meta-Analysis and Review

Longstanding hyperlipidemia can increase the risk of cardiovascular disease. Statins are currently the mainstay of treatment in hyperlipidemia. Combination therapy of statin with ezetimibe is only indicated for severe hypercholesterolemia and very high-risk atherosclerotic cardiovascular disease (ASCVD) population. There is a paucity of studies comparing statin monotherapy vs combination therapy with ezetimibe. This study aims to perform a meta-analysis of the existing literature and compare the effectiveness of statin monotherapy with statin-ezetimibe combination therapy in the management of hyperlipidemia. A systematic electronic search of the scientific literature was performed in PubMed, EMBASE, and Scopus. Only randomized controlled trials comparing simvastatin monotherapy vs simvastatin-ezetimibe combination therapy between the years 2000 and 2021 and published in English language were included. Fifteen studies were included in the final analysis. The main outcomes that were compared were a reduction in low-density lipoprotein (LDL) and high-density lipoprotein (HDL). Our study showed that combination therapy led to a higher reduction of LDL-C (Mean difference: -20.22(-26.38, -14.07); P<0.0001) compared to monotherapy with a statin alone. There was no significant difference in the reduction of HDL-C values (Mean difference: -0.07(-0.45,0.32); P-0.04) between the two groups. Our study indicates that the combination therapy of simvastatin and ezetimibe is more effective in reduction of LDL-C levels compared to simvastatin monotherapy alone. Currently, guidelines recommend combination therapy only for severe hypercholesterolemia and high-risk ASCVD patients, more studies are needed to study the effectiveness of simvastatin-ezetimibe combination therapy in low-risk ASCVD population.