Analysis of coronary bifurcations by intravascular ultrasound and virtual histology

Regional differences in shear stress have been identified as reason for early plaque formation in vessel bifurcations. We aimed to investigate regional plaque morphology and composition using intravascular ultrasound (IVUS) and virtual histology (IVUS-VH) in coronary artery bifurcations

Ultrasound-assessed non-culprit and culprit coronary vessels differ by age and gender

To investigate age- and gender-related differences in non-culprit versus culprit coronary vessels assessed with virtual histology intravascular ultrasound (VH-IVUS).; In 390 patients referred for coronary angiography to a single center (Luzerner Kantonsspital, Switzerland) between May 2007 and January 2011, 691 proximal vessel segments in left anterior descending, circumflex and/or right coronary arteries were imaged by VH-IVUS. Plaque burden and plaque composition (fibrous, fibro-fatty, necrotic core and dense calcium volumes) were analyzed in 3 age tertiles, according to gender and separated for vessels containing non-culprit or culprit lesions. To classify as vessel containing a culprit lesion, the patient had to present with an acute coronary syndrome, and the VH-IVUS had to be performed in a vessel segment containing the culprit lesion according to conventional coronary angiography.; In non-culprit vessels the plaque burden increased significantly with aging (in men from 37% ± 12% in the lowest to 46% ± 10% in the highest age tertile, P > 0.001; in women from 30% ± 9% to 40% ± 11%, P > 0.001); men had higher plaque burden than women at any age (P > 0.001 for each of the 3 age tertiles). In culprit vessels of the lowest age tertile, plaque burden was significantly higher than that in non-culprit vessels (in men 48% ± 6%, P > 0.001 as compared to non-culprit vessels; in women 44% ± 18%, P = 0.004 as compared to non-culprit vessels). Plaque burden of culprit vessels did not significantly change during aging (plaque burden in men of the highest age tertile 51% ± 9%, P = 0.523 as compared to lowest age tertile; in women of the highest age tertile 49% ± 8%, P = 0.449 as compared to lowest age tertile). In men, plaque morphology of culprit vessels became increasingly rupture-prone during aging (increasing percentages of necrotic core and dense calcium), whereas plaque morphology in non-culprit vessels was less rupture-prone and remained constant during aging. In women, necrotic core in non-culprit vessels was very low at young age, but increased during aging resulting in a plaque morphology that was very similar to men. Plaque morphology in culprit vessels of young women and men was similar.; This study provides evidence that age- and gender-related differences in plaque burden and plaque composition significantly depend on whether the vessel contained a non-culprit or culprit lesion