Positive Vascular Remodeling in Culprit Coronary Lesion is Associated With Plaque Composition: An Intravascular Ultrasound-Virtual Histology Study

Background and Objectives: The relationship between the positive remodeling (PR) of a coronary artery and plaque composition has been studied only in a relatively small number of study population or non-culprit lesion. We evaluated the association between coronary plaque composition and coronary artery remodeling in a relatively large number of culprit lesions. Subjects and Methods: The study population consisted of 325 consecutive patients with coronary artery disease that underwent intravascular ultrasound-virtual histology examination in a culprit lesion. The remodeling index (RI) was calculated as the lesion external elastic membrane (EEM) area divided by the average reference EEM area. Results: The lesions with PR (RI>1.05, n=97, mean RI=$1.19{\pm}0.12$) had a higher fibrous volume/lesion length ($3.85{\pm}2.12\;mm^3$/mm vs. $3.04{\pm}1.79\;mm^3$/mm, p=0.003) and necrotic core volume/lesion length ($1.26{\pm}0.89\;mm^3$/mm vs. $0.90{\pm}0.66\;mm^3$/mm, p=0.001) than those with negative remodeling (NR) (RI<0.95, n=132, mean RI=$0.82{\pm}0.09$). At the minimal luminal area site, the lesions with PR had a higher fibrous area ($5.81{\pm}3.17\;mm^2$ vs. $3.61{\pm}2.30\;mm^2$, p<0.001), dense calcified area ($0.73{\pm}0.69\;mm^2$ vs. $0.46{\pm}0.43\;mm^2$, p=0.001), and necrotic core area ($1.93{\pm}1.33\;mm^2$ vs. $1.06{\pm}0.91\;mm^2$, p<0.001) than those with NR. RI showed significant positive correlation with fibrous volume/ lesion length (r=0.173, p=0.002), necrotic core volume/lesion length (r=0.188, p=0.001), fibrous area (r=0.347, p<0.001), fibrofatty area (r=0.111, p=0.036), dense calcified area (r=0.239, p<0.001), and necrotic core area (r=0.334, p<0.001). Multivariate analysis showed that the independent factor for PR was the necrotic core volume/lesion length (beta=0.130, 95% confidence interval; 0.002-0.056, p=0.037) over the entire lesion. Conclusion: This study suggests that PR in a culprit lesion is associated with the necrotic core volume in the entire lesion, which is a characteristic of vulnerable plaque.