Variability of the LDL-C lowering response to ezetimibe and ezetimibe + statin therapy in hypercholesterolemic patients

Objective: We compared the variability of LDL-C-lowering responses to treatment with ezetimibe + statins versus statins in hypercholesterolemic patients.

Methods: An analysis of patient-level data pooled from 27 double-blind, placebo and/or active-controlled studies in 21,671 patients treated with ezetimibe + statins versus statins on first-line (statin-naïve/wash-out) or second-line (on statin, randomized to ezetimibe versus placebo [add-on] or ezetimibe versus uptitrated statin [uptitrate]) for 6-24 wks. Variances (standard deviation [SD], coefficient of variation [CV], and root mean squared error [RMSE] adjusted for various factors) for % change from baseline in LDL-C were compared.

Results: In first-line and second-line add-on studies, the variability (SD, RMSE) of % change from baseline in LDL-C was lower in ezetimibe + statin-treated patients versus statin-treated patients, ±covariates. Differences were small but statistically significant due to the large sample size. In second-line uptitrate studies, ezetimibe + statin treatment resulted in greater unadjusted variability (SD) versus statin therapy, while the adjusted variability (RMSE) was significantly lower. Relative variability (CV=SD/mean) was lower for ezetimibe + statins versus statin therapy for all study types, being more pronounced in second-line add-on and uptitrate studies, attributed to larger mean LDL-C reductions for ezetimibe + statins versus statin groups. When assessed by individual study/type, statin brand, potency or dose, the CVs remained lower for ezetimibe + statins versus statins in second-line studies. The SDs showed no consistent trend for either therapy.

Conclusion: In hypercholesterolemic patients, the absolute variability of LDL-C-lowering responses to ezetimibe + statins was not greater versus statins alone and appeared lower when adjusted for other factors. Relative variability was lower in patients treated with statins + ezetimibe. A better understanding of the variability of the LDL-C lowering response may help guide clinicians in making therapeutic decisions.