Background: The relevance of the IMPROVE-IT trial on real-life practice has not been explored in patients with ACS.

Methods: A prospective Swiss cohort of 6266 patients hospitalized for ACS between 2009 and 2017 with a one-year follow-up. The primary endpoints were the ezetimibe use overall or in combination with high-intensity statin at discharge and at one year after ACS. Secondary endpoint was LDL-C target achievement at one year in a subsample of 2984 patients. Relative Ratios (RR) were used to assess changes in primary endpoints before and after the publication of IMPROVE-IT, adjusting for age, sex, diabetes, prior myocardial infarction, LDL-C and attendance to cardiac rehabilitation.

Results: The period following the publication of the IMPROVE-IT trial was associated with a steady increase in the use of ezetimibe at discharge (from 1.8% to 3.8%, P < 0.001, adjusted RR 2.85, 95% CI 1.90-4.25) and at one year (from 5.0% to 13.8%, P < 0.001, adjusted RR 3.00, 95% CI 2.40-3.75). The combination of high-intensity statin and ezetimibe rose from 0.9% to 2.1% at discharge (P < 0.001, adjusted RR 3.35, 95% CI 1.90-5.89) and from 2.1% to 7.8% at one year (P < 0.001, adjusted RR 3.98, 95% CI 2.90-5.47). The period following the publication of the IMPROVE-IT trial was associated with an improvement of LDL-C target <1.8 mmol/L (adjusted RR 1.37, 95% CI 1.12-1.68).

Conclusions: After the publication of the IMPROVE-IT trial, the use of ezetimibe was increased by three-fold in a large contemporary cohort of ACS patients, concomitant with an improved LDL-C target achievement.