重度冠状动脉左主干分叉病变的血管内超声虚拟组织学临床研究

A clinical study of virtual histology intravascular ultrasound in severe bifurcation lesions of the left main coronary artery

【目的】采用血管内超声(intravascular ultrasound,IVUS)和血管内超声虚拟组织学(intravascular ultrasound virtual histology,IVUS-VH)检查方法分析重度左主干分叉病变的斑块成分和分布特点。【方法】回顾性分析151例需血运重建的重度左主干(直径狭窄率大于50%)分叉病变患者的IVUS-VH数据,分别测量前降支近端(proximal left anterior descending,LADP)和左主干(left main coronary,LMCA)两个节段内的最小管腔面积(minimal lumen area,MLA)位置处及坏死成分(necrotic core,NC)最大位置处的斑块负荷(plaque burden,PB)与NC成分比例。【结果】冠脉造影(coronary angiography,CAG)显示单纯重度LMCA分叉病变以及同时累及LAD开口的患者分别占88.7%、81.5%。LADP与LMCA节段内的MLA位置处相比呈较小的冠脉横断面残留管腔面积(lumen area,LA)(3.8±1.4)mm^2和较大的斑块负荷(plaque burden,PB)(72.5±8.6)%,组间差异有统计学意义(P<0.05),同时IVUS-L从LADP节段向LMCA节段呈减少的趋势;LADP与LMCA节段内的NC最大位置处相比呈较大的NC成分比例(34.7±7.2)%和较高的虚拟组织学薄纤维帽斑块(virtual histology thin-cap fibroatheroma,VH-TCFA)发生率(67.6%),组间差异有统计学意义(P<0.05),因此冠状动脉粥样硬化斑块从LADP节段向LMCA节段连续分布。【结论】在冠状动脉重度LMCA分叉病变患者中,LADP节段比LMCA节段内的管腔面积小,其斑块负荷重,易损斑块发生率高于LMCA节段。

【Objective】To analyze the composition and distribution of plaques in the bifurcation lesions of the left main coronary artery(LMCA)via intravascular ultrasound(IVUS)and IVUS virtual histology(IVUS-VH).【Methods】The IVUS-VH data of 151 patients with severe LMCA bifurcation lesions(angiographic diameter stenosis>50%)in requirement of revascularization were retrospectively analyzed.The plaque burden(PB)and percentage of necrotic core(%NC)at the minimal lumen area(MLA)and maximal%NC site were measured in two segments,proximal left anterior descending(LADP)and LMCA.【Results】The results of coronary angiography(CAG)showed that a significant LMCA and ostial LAD stenosis appeared in 88.7%and 81.5%of patients respectively.At the MLA site,the proximal LAD segment showed the smallest lumen(3.8±1.4)mm2 and the greatest PB(72.5±8.6)%compared with the LMCA,and the difference was statistically significant(P<0.05).Moreover,there was a significant downward trend in the IVUS-defined lesions(IVUSL)toward the LMCA.At the maximal%NC site,the LADP segment showed the higher necrotic core(34.7±7.2)%and the most frequent virtual histology thin-cap fibroatheroma(TCFA)(67.6%),and the difference was statistically significant(P<0.05).Fibroatheroma was distributed in a continuous pattern from the proximal LAD to the LMCA.【Conclusion】In the severe LMCA bifurcation diseases,the LADP segment is found to have the smallest lumen,the largest PB and the highest virtual histology TCFA rate,and present the most vulnerabable characteristics by IVUS-VH.