Effect of Low-Density Lipoprotein Cholesterol Lowering by Ezetimibe/Simvastatin on Outcome Incidence: Overview, Meta-Analyses, and Meta-Regression Analyses of Randomized Trials

Clin Cardiol. 2015 Dec;38(12):763-9. doi: 10.1002/clc.22441. Epub 2015 Aug 18.

Abstract

This analysis investigated the extent of different outcome reductions from low-density lipoprotein cholesterol (LDL-C) lowering following ezetimibe/simvastatin treatment and the proportionality of outcome to LDL-C reductions. The authors searched PubMed between 1997 and mid-June 2015 (any language) and the Cochrane Library to identify all randomized controlled trials comparing ezetimibe/simvastatin with placebo or less intensive LDL-C lowering. Risk ratios (RR) and 95% confidence intervals (CIs), standardized to 20 mg/dL LDL-C reduction, were calculated for 5 primary outcomes (fatal and nonfatal) and 4 secondary outcomes (non-cardiovascular [CV] death, cancer, myopathy, and hepatopathy). Five ezetimibe/simvastatin RCTs (30 051 individuals) were eligible, 2 comparing ezetimibe/simvastatin vs placebo and 3 vs less intensive treatment. Outcomes reduced almost to the same extent were stroke (RR: -13%, 95% CI: -21% to -3%), coronary heart disease (CHD; RR: -12%, 95% CI: -19% to -5%), and composite of stroke and CHD (RR: -14%, 95% CI: -20% to -8%). Absolute risk reductions: 5 strokes, 10 CHD events, and 16 stroke and CHD events prevented for every 1000 patients treated for 5 years. Residual risk was almost 7× higher than absolute risk reduction for all the above outcomes. All death outcomes were not reduced, and secondary outcomes did not differ between groups. Logarithmic risk ratios were not associated with LDL-C lowering. Our meta-analysis provides evidence that, in patients with different CV disease burden, major CV events are safely reduced by LDL-C lowering with ezetimibe/simvastatin, while raising the hypothesis that the extent of LDL-C lowering might not be accompanied by incremental clinical-event reduction.

Publication types

  • Meta-Analysis
  • Review

MeSH terms

  • Anticholesteremic Agents / adverse effects
  • Anticholesteremic Agents / therapeutic use*
  • Cardiovascular Diseases / drug therapy
  • Cardiovascular Diseases / epidemiology
  • Cardiovascular Diseases / prevention & control
  • Cholesterol, LDL / drug effects*
  • Drug Therapy, Combination
  • Ezetimibe / administration & dosage
  • Ezetimibe / adverse effects
  • Ezetimibe / therapeutic use*
  • Humans
  • Hypercholesterolemia / complications
  • Hypercholesterolemia / drug therapy*
  • Incidence
  • Randomized Controlled Trials as Topic
  • Simvastatin / administration & dosage
  • Simvastatin / adverse effects
  • Simvastatin / therapeutic use*
  • Treatment Outcome

Substances

  • Anticholesteremic Agents
  • Cholesterol, LDL
  • Simvastatin
  • Ezetimibe