High-Density Lipoprotein Cholesterol and Cardiovascular Events in Patients with Stable Coronary Artery Disease Treated with Statins: An Observation from the REAL-CAD Study

Aim: The association between high-density lipoprotein cholesterol (HDL-C) level after statin therapy and cardiovascular events in patients with stable coronary artery disease (CAD) remains unclear. Thus, in this study, we sought to determine how HDL-C level after statin therapy is associated with cardiovascular events in stable CAD patients. Methods: From the REAL-CAD study which had shown the favorable prognostic effect of high-dose pitavastatin in stable CAD patients with low-density lipoprotein cholesterol (LDL-C) ＜120 mg/dL, 9,221 patients with HDL-C data at baseline and 6 months, no occurrence of primary outcome at 6 months, and reported non-adherence for pitavastatin, were examined. The primary outcome was a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal ischemic stroke, or unstable angina requiring emergent admission after 6 months of randomization. Absolute difference and ratio of HDL-C levels were defined as (those at 6 months–at baseline) and (absolute difference/baseline)×100, respectively. Results: During a median follow-up period of 4.0 (IQR 3.2–4.7) years, the primary outcome occurred in 417 (4.5%) patients. The adjusted risk of all HDL-C-related variables (baseline value, 6-month value, absolute, and relative changes) for the primary outcome was not significant (hazard ratio [HR] 0.99, 95% confidence interval [CI] 0.91–1.08, HR 1.03, 95% CI 0.94–1.12, HR 1.05, 95% CI 0.98–1.12, and HR 1.08, 95% CI 0.94–1.24, respectively). Furthermore, adjusted HRs of all HDL-C-related variables remained non-significant for the primary outcome regardless of on-treatment LDL-C level at 6 months. Conclusions: After statin therapy with modestly controlled LDL-C, HDL-C level has little prognostic value in patients with stable CAD.