Lower Levels of Low-density Lipoprotein Cholesterol Are Associated with a Lower Prevalence of Thin-cap Fibroatheroma in Statin-treated Patients with Coronary Artery Disease

Background: Reducing low-density lipoprotein cholesterol (LDL-C) levels with statins slows the progression of atherosclerotic plaques and reduces cardiovascular events. The 2019 European Society of Cardiology/European Atherosclerosis Society guidelines recommend absolute LDL-C treatment targets of <100 mg/dL, <70 mg/dL and <55 mg/dL according to coexisting patient risk factors.

Objective: To clarify the difference in the plaque characteristics of coronary lesions associated with these LDL-C levels in statin-treated patients.

Methods: A total of 685 consecutive statin-treated patients with coronary artery disease (CAD) who underwent optical coherence tomography (OCT) imaging of culprit lesions were enrolled. The characteristics of culprit plaques evaluated by OCT were compared among the high LDL-C group (≥100 mg/dL, n=247), the moderate LDL-C group (70-100 mg/dL, n=289), the low LDL-C group (55-70 mg/dL, n=106) and the very low LDL-C group (<55 mg/dL, n=43).

Results: A significant trend toward a lower prevalence of thin-cap fibroatheroma (TCFA) associated with the LDL-C groups was observed (23.1, 18.3, 9.4 and 11.6%, respectively, in each group; p=0.002). A trend toward a lower prevalence of TCFAs associated with the LDL-C groups was also observed among patients with lower hemoglobin A1c (<6.2%; p=0.003). LDL-C <70 mg/dL (the low/very low group) was independently associated with the lack of TCFAs (odds ratio, 0.50; 95% confidence interval, 0.27-0.87, p=0.014).

Conclusions: Lower LDL-C levels were associated with a lower prevalence of TCFAs in culprit plaques among statin-treated patients with CAD.