Background and Aim: The relevance of statin therapy in acute coronary syndrome (ACS) is well-established, but little is known about the optimal timing of statin administration, particularly within the first 24 hours following ACS. (1, 2) The aim of the study was to gather data on early and late outcomes of ACS patients (pts) through the Croatian branch of the ISACS-CT (International Registry of Acute Coronary Syndromes in Transitional Countries) registry.

Patients and Methods: The data was gathered retrospectively from January 2012 to October 2017. The study population included 1898 ACS pts: 46.4% (n=881) with ST-segment elevation myocardial infarction (STEMI), 36.1% (n=685) with non-ST-segment elevation myocardial infarction (NSTEMI) and 17.5% (n=332) with unstable angina pectoris (UA). Follow-up was performed on 33% (n=630) of the cohort, 43.7% (n=275) with STEMI, 34.4% (n=217) NSTEMI and 21.9% (n=138) with UA.

Results: In the first 24 hours following ACS, statins were administered in 1734 (93%) pts (for 24 pts the data is missing), while the pts who received them later or not at all were the control group. The two groups did not differ regarding age, gender, body mass index, left ventricular ejection fraction (LVEF) during initial hospitalization, smoking status, history of diabetes, chronic heart failure or arterial hypertension at initial hospitalization nor at 1-year follow-up (Table 1). The overall in-hospital mortality rate was 4%, similar to that in pts treated with statins within the first 24 hours (3%), while in pts without early statin treatment, in-hospital mortality rate was 18% (p<0.001). The risk of in-hospital death was significantly higher in pts without early statin therapy (odds ratio [OR] 7.32, 95% confidence interval [CI] 4.371-12.27, p<0.001), while the risk of primary outcome at 1-year follow-up was not significantly different between groups in univariate regression analysis. Older age (OR 1.1, 95% CI 1.06-1.20, p< 0.001), higher creatinine level (OR 1.0, 95% CI 1.005-1.012, p<0.001), lower LVEF (OR 0.90, 95%CI 0.86-0.94, p<0.001) and lack of early statin treatment (OR 3.6, 95% CI 1.0-13.10, p=0.05) were positively associated with increased odds for early primary outcome in multivariable regression model (Table 2).

Conclusion: Initiation of statin therapy within the first 24 hours following ACS is associated with a significant reduction in in-hospital mortality, although the positive effect of early statin therapy did not reach statistical significance at 1-year follow-up.