On-treatment analysis of the Improved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT)

Am Heart J. 2016 Dec:182:89-96. doi: 10.1016/j.ahj.2016.09.004. Epub 2016 Sep 23.

Abstract

Background: We aimed to determine the efficacy and safety of adding ezetimibe (Ez) to simvastatin (S) in a post-acute coronary syndrome (ACS) population in a prespecified on-treatment analysis.

Methods: We evaluated 17,706 post-ACS patients from the IMPROVE-IT trial who had low-density lipoprotein cholesterol values between 50 and 125 mg/dL and who received Ez 10 mg/d with S 40 mg/d (Ez/S) or placebo with simvastatin 40 mg/d (P/S). The primary composite end point was cardiovascular death, myocardial infarction, unstable angina, coronary revascularization ≥30 days postrandomization, or stroke. The on-treatment analysis included patients who received study drug for the duration of the trial or experienced a primary end point or noncardiovascular death within 30 days of drug discontinuation.

Results: Mean low-density lipoprotein cholesterol values at 1 year were 71 mg/dL for P/S and 54 mg/dL for Ez/S (absolute difference -17 mg/dL = -24%; P < .001). The 7-year Kaplan-Meier estimate of the primary end point occurred in 32.4% in the P/S arm and 29.8% in the Ez/S arm (absolute difference 2.6%; HRadj 0.92 [95% CI 0.87-0.98]; P = .01). The absolute treatment effect favoring Ez/S was 30% greater than in the intention-to-treat analysis of IMPROVE-IT.

Conclusions: This analysis provides additional support for the efficacy and safety of adding Ez to S in this high-risk, post-ACS population.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Acute Coronary Syndrome* / blood
  • Acute Coronary Syndrome* / diagnosis
  • Acute Coronary Syndrome* / drug therapy
  • Aged
  • Anticholesteremic Agents / administration & dosage
  • Anticholesteremic Agents / adverse effects
  • Cholesterol, LDL / blood*
  • Dose-Response Relationship, Drug
  • Drug Monitoring / methods
  • Drug Synergism
  • Drug Therapy, Combination / methods
  • Drug Therapy, Combination / statistics & numerical data
  • Ezetimibe* / administration & dosage
  • Ezetimibe* / adverse effects
  • Female
  • Humans
  • Male
  • Middle Aged
  • Simvastatin* / administration & dosage
  • Simvastatin* / adverse effects
  • Treatment Outcome

Substances

  • Anticholesteremic Agents
  • Cholesterol, LDL
  • Simvastatin
  • Ezetimibe