Relationship between coronary artery remodeling and plaque composition in culprit lesions: an intravascular ultrasound radiofrequency analysis.

BACKGROUND: The relationship between coronary artery remodeling and culprit plaque composition in vivo has not been fully evaluated by spectral analysis of intravascular ultrasound (IVUS) radiofrequency (RF) data. METHODS AND RESULTS: IVUS RF analyses were performed for 56 consecutive de novo culprit lesions of 52 patients undergoing percutaneous coronary intervention. Remodeling of culprit lesions was determined using the remodeling index (RI), calculated as the external elastic membrane area of the minimum lumen area (MLA) site divided by that of the proximal reference site. Positive remodeling was defined as RI >1.05, intermediate remodeling as 0.95< or = RI < or =1.05 and negative remodeling as RI <0.95. Among the 56 lesions, positive remodeling was detected in 24, intermediate remodeling in 16, and negative remodeling in 16. At MLA sites, positive remodeling lesions had a larger percentage of the fibrofatty component than negative remodeling lesions (22.5+/-10.3% vs 10.4+/-6.6%, p=0.0001), whereas the latter contained a larger percentage of the dense calcium component than the former (2.8+/-2.9% vs 8.4+/-7.0%, p=0.016). CONCLUSIONS: Culprit plaques with positive remodeling have a large lipid burden, whereas those with negative remodeling contain a large amount of calcium.