Introduction
A high-intensity statin, defined as atorvastatin 40mg or 80mg and rosuvastatin 20mg or 40mg orally, which lowers low-density lipoprotein cholesterol (LDL-C) by ≥50%, is recommended by clinical practice guidelines for secondary prevention of cardiovascular events among patients who have an atherosclerotic cardiovascular disease (CVD) (Class 1A).1,2 Several clinical trials have demonstrated that statin use reduces major cardiovascular events.3–10Specifically, large randomized controlled clinical trials have established the efficacy and safety of statins for secondary prevention of CVDs.8–10 The Intensive versus Moderate Lipid Lowering with Statins after Acute Coronary Syndromes (PROVE IT) trial that compared atorvastatin 80mg to pravastatin 40mg demonstrated a risk reduction of 16% over two years in the composite endpoint of all-cause mortality, myocardial infarction, documented unstable angina requiring re-hospitalization, revascularization (performed at least 30 days after randomization), and stroke among patients with the acute coronary syndrome (ACS).8 Additionally, the Intensive Lipid Lowering with Atorvastatin in Patients with Stable Coronary Disease (TNT) trial that compared atorvastatin 80mg to 10mg showed a risk reduction of 22% over 4.9 years in a major adverse cardiovascular event (MACE), defined as cardiovascular death, non-fatal myocardial infarction, resuscitation after cardiac arrest, and fatal or non-fatal stroke.9 Similarly, in the Effects of Atorvastatin on Early Recurrent Ischemic Events in Acute Coronary Syndrome (MIRACL) trial, the early use of atorvastatin 80mg after ACS compared to placebo had resulted in a 16% significant reduction in a primary composite outcome of mortality, non-fatal myocardial infarction, and cardiac arrest with resuscitation over a follow-up period of 16 weeks.10
Therefore, the use of atorvastatin 80mg among patients with coronary artery disease (CAD) had resulted in a risk reduction of 16-22% in MACE. However, to the best of our knowledge, the secondary prevention cardiovascular benefit of atorvastatin 40mg compared to 80mg in the setting of ACS has not yet been well-established. Although the CURE-ACS trial compared both doses among ACS patients in terms of LDL-C reduction11, there is no head-to-head comparison between atorvastatin 40mg and 80mg to assess the cardiovascular secondary prevention effect of the two regimens. Therefore, this retrospective, observational cohort study aimed to compare using real-world data the effectiveness and safety of two high-intensity statin doses (atorvastatin 40mg vs. 80mg) in patients with ACS at 1 month and 12 months post-discharge, and to determine the predictors of prescribing 80mg upon discharge.