Relation of plaque size to compositions as determined by an in vivo volumetric intravascular ultrasound radiofrequency analysis

As the plaques have enlarged, the changes in specific plaque compositions have not been sufficiently investigated. We evaluated the relation of plaque size to each plaque component (fibrotic, fibrofatty, dense calcium, and necrotic core) in 244 patients with volumetric virtual histology intravascular ultrasound analysis. Plaque volume was significantly correlated with fibrotic volume (r = 0.886, P < 0.001), necrotic core volume (r = 0.716, P < 0.001), fibrofatty volume (r = 0.572, P < 0.001), and dense calcium volume (r = 0.382, P < 0.001). There was a weak correlation between plaque volume and percentage of fibrofatty plaque and dense calcium (r = 0.140, P = 0.030 and r = -0.146, P = 0.023, respectively). Plaque volume was not significantly correlated with percentage of fibrotic plaque and necrotic core. As the plaque volume increased, there was an increase in absolute amounts of each plaque component (fibrotic > necrotic core > fibrofatty > dense calcium). However, there were no significantly relevant correlations between plaque volume and percentage of each plaque component.