Proportion and Magnitude of LDL-C Reduction Following CABG with Low-Dose Statin Therapy: A Retrospective Cohort Study

Abstract

Objectives: Patients undergoing coronary artery bypass grafting (CABG) require intensive lipid lowering as part of secondary prevention. However, real-world achievement of guideline-recommended ≥50% LDL-C reduction with low-dose statin therapy remains uncertain. Aim of this study was to determine the proportion of patients achieving ≥50% LDL-C reduction and to assess the magnitude of LDL-C reduction over time among post-CABG patients receiving 20 mg dose of statins. Methodology: This retrospective cohort study included 170 post-CABG patients receiving low-dose statin therapy. LDL-C levels were recorded at baseline and at 3, 6, and 12 months. The primary outcome was the proportion of patients achieving ≥50% LDL-C reduction at each time point. Within-subject changes over time were assessed using the Friedman test, with post-hoc pairwise comparisons conducted using Wilcoxon signed-rank tests with Bonferroni correction. Results: Median LDL-C reduction increased progressively from 16.3% (IQR: 10.7–21.0) at 3 months to 31.0% (IQR: 19.6–35.4) at 6 months and 45.9% (IQR: 25.7–50.6) at 12 months. Differences across time points were statistically significant (Friedman χ² = 423.9, p < 0.001; Kendall’s W = 0.836). No patients achieved ≥50% LDL-C reduction at 3 or 6 months, whereas 28.8% (95% CI: 22.5–36.1) achieved this target at 12 months. Mean LDL-C declined from 152.9 ± 20.6 mg/dL at baseline to 94.7 ± 27.6 mg/dL at 12 months. Conclusion: LDL-C reduction following CABG with low-dose statins is progressive over time; however, achievement of ≥50% reduction is limited within the first year. These findings highlight the need for closer monitoring and potential treatment intensification.