The sequence of changes in intravascular imaging findings during lipid-lowering therapy and its implication

Over the past two decades, studies with serial coronary imaging have consistently shown favorable changes in plaque phenotype in response to lipid-lowering therapy (LLT). Here, we review these studies, which had varied follow-up periods, to examine the time course of changes in plaque phenotype. The plaque response to LLT appears to start with the thickening of the fibrous cap, followed by a decrease in lipid components and ultimately a regression in plaque volume. Thickening of the fibrous cap is not only the earliest and most sensitive response to LLT but, in combination with a reduction in lipid components, provides protection from coronary artery disease. The small yet significant regression in plaque volume observed in serial studies is suggested to be more indicative of plaque stabilization than lumen expansion. The insight gained from integrating the current literature will help inform better lipid management in clinical practice and guide the design of future studies.