Physicians' Academy for Cardiovascular Education
Greater increase in minimum fibrous cap thickness by PCSK9i after NSTEMI

Greater increase in minimum fibrous cap thickness by PCSK9i after NSTEMI

News - Aug. 29, 2021

Assessing the impact of PCSK9 inhibition on coronary plaque phenotype with optical coherence tomography: Primary results of the HUYGENS study

Presented at the ESC congress 2021 by: Prof. Stephen Nicholls, MD, PhD Melbourne, Australia

Introduction and methods

Previous studies with IVUS have shown that high intensity statins with and without PCSK9 inhibitors result in plaque regression and that the degree of plaque regression was proportional to LDL-c lowering. Plaque vulnerability plays an important role in residual CV risk, but the impact of lipid lowering on plaque vulnerability is unknown.

In the HUYGENS study the impact of evolocumab on top of statin therapy on plaque phenotype was examined in patients post-ACS.

Patients with NSTEMI, angiographic CAD and qualifying LDL-c dependent on prior statin use, intend to be subsequently treated with maximally tolerated statin, target segment on optical coherence tomography (OCT) containing at least one image with fibrous cap thickness (FCT) <120 µm and one image with lip arc >90° were recruited. Patients were randomized to evolocumab 420 mg SC monthly or matching placebo, in addition to background lipid lowering therapy. Patients underwent OCT at baseline and at week 50. There were 135 patients who completed the study.

OCT analysis was performed on cross-sectional images 0.2 mm apart through a matched arterial segment. Analysis included measurement of the minimum FCT and extent of lipid arc in each image. Primary endpoint was the change in minimum FCT anywhere in the segment.

Main results


In the HUYGENS study, addition of evolocumab to maximally tolerated statins for 12 months resulted in a greater increase in the minimum FCT and decreases in the maximum lipid arc, throughout the vessel and in lipid rich plaques, when compared to placebo on top of maximally tolerated statins. The degree of benefit on plaque phenotype was proportional to the intensity of lipid lowering.

Prof. Nicholls concluded that these findings suggest that vulnerable plaques can be stabilized after an ACS and this should motivate the use of intensive lipid lowering therapies in patients post-ACS.

- Our reporting is based on the information provided at the ESC Congress -

Greater increase in minimum fibrous cap thickness by PCSK9i after NSTEMI

The rationale and design of this study were published in Cardiovasc Diagn Ther.

Share this page with your colleagues and friends: