Prognostic Implication of LDL-C Variability and Its Association with Lipid-Lowering Strategies: Insights from the RACING and LODESTAR Trials

Abstract

Purpose: We aimed to compare the visit-to-visit variability in low-density lipoprotein cholesterol (LDL-C) according to different lipid-lowering strategies and evaluate its prognostic implications using data from previous trials. Materials and Methods: We analyzed two randomized clinical trials: the RACING trial and the LODESTAR trial. LDL-C variability was evaluated using standard deviation (SD), coefficient of variation, and variation independent of mean. The primary endpoint was a composite of death, myocardial infarction, stroke, or coronary revascularization. Results: Among the 6800 patients included, when compared with patients randomized to high-intensity statins, LDL-C variability was similar in the group randomized to moderate-intensity statin plus ezetimibe combination, but it was higher in those randomized to treat-to-target strategy. The variability in LDL-C (by SD) was a predictor of primary endpoint even after adjustment for lipidlowering strategy and mean LDL-C (hazard ratio 1.024; 95% confidence interval 1.014 to 1.035; p<0.001). Every 1-SD increase in LDLC variability (SD) was also independently associated with higher risk of myocardial infarction by 2.1%, stroke by 3.5%, and coronary revascularization by 2.7%. Conclusion: Compared to high-intensity statin therapy, LDL-C variability was not increased with the moderate-intensity statin plus ezetimibe combination therapy; however, it was increased in the treat-to-target strategy. Even among those treated with moderate-or high-intensity statins or statins with a target LDL-C levels of 50−70 mg/dL, increased LDL-C variability was associated with higher risk of adverse cardiovascular outcomes.