Effect of Alirocumab on Coronary Plaque in Patients With Coronary Artery Disease Assessed by Optical Coherence Tomography

Background: Proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitors have been demonstrated with significant greater reduction of LDL cholesterol levels and cardiovascular events, compared with standard statin therapy. However, the evidence on the impact of PCSK9 inhibitors on coronary plaque composition and morphology are limited. Methods: In this prospective, open-label, randomized study, eligible patients with intermediate coronary lesions and elevated LDL cholesterol values were randomized to either alirocumab 75 mg Q2W plus statin therapy (alirocumab arm) or statin therapy (standard care arm). Optical coherence tomography (OCT) assessment for target lesions were obtained at the baseline and at 36 weeks of follow-up. Results: LDL cholesterol levels were significantly decreased in both alirocumab arm and standard care arm, whereas the absolute reduction of LDL cholesterol was significantly greater in patients with alirocumab (1.72±0.51 vs 0.96±0.59, P<0.0001). Compared with standard statin therapy, the addition of alirocumab to statins was associated with significant greater increase in minimum fibrous cap thickness (18.0 [10.8- 29.2]um vs 13.2 [7.4-18.6]um; P=0.029), minimum lumen area (0.20[ 0.10-0.33]mm 2 vs 0.13 [0.12-0.24]mm 2 ; P=0.006) and greater diminution in maximum lipid arc (15.1 ̊ [7.8 -24.5] vs. 8.4 ̊ [2.0 -10.5]; P=0.008). Conclusions: The addition of alirocumab to statins can not only provide additional LDL cholesterol lowering effect but also have a potential role in promoting a more stable plaque phenotype.