The "Melting Butter Sign" of Coronary Plaque Delipidation: Insights From the YELLOW III Trial

CASE SUMMARY: A 53-year-old man with chronic coronary disease and a nontarget, nonflow-limiting lipid-rich coronary plaque was serially assessed with near-infrared spectroscopy, optical coherence tomography, and intravascular ultrasound. After 26 weeks of evolocumab added to maximally tolerated statin therapy, near-infrared spectroscopy showed marked attenuation of confluent lipid signal ("Melting Butter Sign"), accompanied by fibrous cap thickening on optical coherence tomography, with unchanged plaque burden on intravascular ultrasound. TAKE-HOME MESSAGE: The "Melting Butter Sign" represents imaging-defined plaque delipidation and early stabilization after intensive lipid-lowering therapy with evolocumab.