Low-Density Lipoprotein Cholesterol Levels on Statins and Cardiovascular Event Risk in Stable Coronary Artery Disease - An Observation From the REAL-CAD Study.

Background: The relationship between very low on-treatment low-density lipoprotein cholesterol (LDL-C) level and cardiovascular event risk is still unclear in patients receiving the same doses of statins.

Methods and results: From the REAL-CAD study comparing high-dose (4 mg/day) with low-dose (1 mg/day) pitavastatin therapy in patients with stable coronary artery disease, 11,105 patients with acceptable statin adherence were divided into 3 groups according to the on-treatment LDL-C level at 6 months (<70 mg/dL, 70-100 mg/dL, and ≥100 mg/dL). The primary outcome measure was a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal ischemic stroke, or unstable angina requiring emergent admission. The adjusted risks of the LDL-C <70 mg/dL group relative to the LDL-C 70-100 mg/dL group (reference) was not significantly different for the primary outcome measure in both 1 mg/day and 4 mg/day strata (HR 0.84, 95% CI 0.58-1.18, P=0.32, and HR 1.25, 95% CI 0.88-1.79, P=0.22). The adjusted risk of the LDL-C ≥100 mg/dL group relative to the reference group was not significant for the primary outcome measure in the 1 mg/day stratum (HR 0.82, 95% CI 0.60-1.11, P=0.21), whereas it was highly significant in the 4 mg/day stratum (HR 3.32, 95% CI 2.08-5.17, P<0.001).

Conclusions: A very low on-treatment LDL-C level (<70 mg/dL) was not associated with lower cardiovascular event risk compared with moderately low on-treatment LDL-C level (70-100 mg/dL) in patients receiving the same doses of statins.