Efficacy and safety of combination therapy with statin and ezetimibe in patients failing to achieve target LDL levels at cardiology outpatient clinics in Turkey (COM-TR-OLDL): a real-world observational study

Background Achieving target low-density lipoprotein cholesterol (LDL-C) levels in patients with atherosclerotic cardiovascular disease (ASCVD) frequently requires combination lipid-lowering therapy. Single-pill combination (SPC) regimens may improve adherence compared with free-dose combinations (FDC) in real-world clinical practice. Methods This retrospective observational study included 450 ASCVD patients with baseline LDL-C levels of 70–189 mg/dL who were followed in cardiology outpatient clinics between January 2023 and December 2024. Patients received atorvastatin–ezetimibe either as a single-pill combination (SPC, n = 392) or as a free-dose combination (FDC, n = 58). Primary endpoints were LDL-C reduction and treatment adherence (≥ 80% of prescribed doses). Secondary endpoints included LDL-C target attainment and adverse events. Non-parametric tests and chi-square/Fisher’s exact tests were used for statistical analysis. Results At 1 month, LDL-C levels were significantly lower in the SPC group compared with the FDC group (90.6 vs. 119 mg/dL; p = 0.005), and adherence was higher (89.8% vs. 70.7%; p < 0.001). At 4 months, LDL-C levels were comparable between groups, while continuous adherence remained significantly higher in the SPC group (86% vs. 69%; p = 0.001). A higher proportion of SPC-treated patients achieved LDL-C < 100 mg/dL at 1 month (81.9% vs. 67.2%; p = 0.009). Conclusions In this real-world ASCVD cohort, SPC therapy with atorvastatin and ezetimibe was associated with superior adherence and comparable lipid-lowering efficacy despite lower statin doses. Fixed-dose combination strategies may represent an effective approach to optimize adherence and cardiovascular risk management.