Abstract 3779: Arterial Wall Remodeling in Response to Atheroma Regression with Very Intensive Lipid Lowering: Insights from the ASTEROID Trial
Background: Early atheroma regression is accompanied by contraction of the external elastic membrane (EEM) and no changes in lumen dimensions. This study aimed to investigate the pattern of arterial wall remodeling that accompanies long term atheroma regression in response to very intensive lipid lowering.
Methods: 349 subjects with angiographic coronary artery disease underwent serial assessment of plaque progression by intravascular ultrasound in response to treatment with rosuvastatin 40mg daily. Changes in the dimensions of the lumen and EEM in the entire cohort and subjects that underwent plaque regression (decrease in percent atheroma volume, PAV) and progression (increase in PAV) were investigated.
Results: Serial changes in lumen and external elastic membrane (EEM) volumes are summarized in the table⇓ below. Reductions in PAV (−0.8%, p<0.0001) and total atheroma volume (TAV, −12.5 mm3, p<0.0001) were accompanied by reductions in lumen volume by 3.1% and EEM volume by 4.7%. Atheroma regression was accompanied by a 3.9% reduction in EEM and no change in lumen volumes. Substantial regression was not only associated with a similar 3.2% reduction in EEM, but also a 3.5% increase in lumen. Plaque progression was accompanied by 5.8% reductions in EEM and 9.1% reduction in lumen. Substantial progression was accompanied by a similar 5.7% reduction in EEM and a greater degree of luminal contraction (11.7%).
Conclusion: Mild degrees of atheroma regression are accompanied by contraction of the EEM without changes in the lumen. With increasing degrees of regression, EEM contraction is accompanied by luminal enlargement. This highlights the dynamic nature of arterial wall remodeling in response to long term, substantial atheroma regression.