916-84 Balloon Angioplasty Evaluated In Vitro by Intracoronary Ultrasound: A Validation with Histology

Abstract

To determine whether one single cross-section obtained with intracoronary ultrasound (ICUS) at the most stenotic site is representative for the ultimate outcome following balloon angioplasty, 25 coronary artery specimens were studied in vitro using a displacement sensing device. Corresponding ultrasound cross-sections (n = 250) were compared with their histologic counterpart. Prior to intervention the sensitivity and specificity of eccentric/3concentric and soft/hard was high (≥ 94%); the specificity of lipid was high (81%), whereas its sensitivity was low (31%). Following intervention the specificity of morphologic features present was higher than the sensitivity: dissection 100% vs 60%; plaque rupture 93% vs 16%; and internal elastic lamina rupture 94% vs 54%. Similar data were obtained for all crosssections and at the most stenotic site. The incidence of pathologic changes at the most stenotic site was higher compared to the overall result. Considering all cross-sections evaluated. concentric lesions were more frequently associated with a dissection and plaque rupture than eccentric lesions; no such relation was evidenced at the most stenotic site. As result of balloon angioplasty ICUS imaging revealed an increase in free lumen area (FLA) and media-bounded area (MBA), whereas plaque area (PLA) reduced slightly. Large differences were encountered when mean values were compared with values obtained at the most stenotic site: FLA increase 30% vs 60% and MBA increase 12% vs 20%. No differences were found in mean PLA reduction and PLA reduction at the most stenotic site (5% vs 8%). This is the first in vitro study that systematically examined coronary arteries with ICUS before and after balloon angioplasty. Comparing the overall data obtained within the dilated specimen to the most stenotic site it was found that similar data were obtained for sensitivity and specificity. The pathologic and quantitative changes seen at the most stenotic site following intervention were more outspoken compared to the overall data.