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 +/- 0.12) had a higher fibrous volume/lesion length (3.85 +/- 2.12 mm(3)/mm vs. 3.04 +/- 1.79 mm(3)/mm, p=0.003) and necrotic core volume/lesion length (1.26 +/- 0.89 mm(3)/mm vs. 0.90 +/- 0.66 mm(3)/mm, p=0.001) than those with negative remodeling (NR) (RI<0.95, n=132, mean RI=0.82 +/- 0.09). At the minimal luminal area site, the lesions with PR had a higher fibrous area (5.81 +/- 3.17 mm(2) vs. 3.61 +/- 2.30 mm(2), p<0.001), dense calcified area (0.73 +/- 0.69 mm(2) vs. 0.46 +/- 0.43 mm(2), p=0.001), and necrotic core area (1.93 +/- 1.33 mm(2) vs. 1.06 +/- 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.