Effect of Evolocumab on Coronary Plaque Phenotype and Burden in Statin-Treated Patients with NSTEMI

This RCT enrolled 161 patients with NSTEMI who were on high-intensity statin therapy and randomized them to evolocumab or placebo, using optical coherence tomography (OCT) to assess culprit plaque phenotype changes at baseline and 52 weeks.

Evolocumab significantly increased fibrous cap thickness — a direct measure of plaque stability — and reduced lipid arc and lipid index in culprit lesions compared with placebo. These are the biological characteristics associated with reduced risk of future plaque rupture and recurrent ACS. Non-culprit plaque burden by IVUS also decreased more in the evolocumab arm.

The findings are important for several reasons. First, OCT provides direct visualization of the plaque microstructure that IVUS cannot resolve — fibrous cap thickness is the most mechanistically relevant measure of plaque stability. Second, demonstrating that very low LDL-C achieved by statin plus PCSK9 inhibitor produces structural plaque changes that should reduce rupture risk provides a mechanistic rationale for aggressive lipid lowering beyond what statins alone achieve. Third, the post-ACS context represents the highest-risk window, where additional plaque stabilization could translate directly to clinical benefit.

We rate the evidence strong. A well-executed OCT-IVUS trial demonstrating that evolocumab combined with high-intensity statins produces meaningful plaque stabilization and regression in post-NSTEMI patients — some of the most mechanistically compelling evidence for aggressive LDL lowering.