冠状动脉不稳定斑块血管内超声特征的临床研究

目的　探讨冠状动脉不稳定斑块的血管内超声 (IVUS)的特点。方法　在 31例急性冠脉综合征 (ACS,其中不稳定心绞痛 19例 ,急性心肌梗死 12例 )和 12例稳定性心绞痛患者中进行冠状动脉造影及 IVUS检查。应用 IVUS分别观察比较冠状动脉内斑块的性质 ,同时测量冠脉病变部位及其参考部位的血管外弹力膜面积 (EEMA)、管腔面积 (L A)、斑块面积 (PA)及管腔面积狭窄率 ,并计算斑块的偏心指数 (EI)及血管的重构指数(RI)。结果　在 4 3例患者中发现 ,不稳定心绞痛与急性心肌梗死中脂质斑块分别占 73.7% (14 / 19)及 75 .0 % (9/ 12 ) ,而稳定性心绞痛主要为纤维性斑块及混合性斑块 ,脂质斑块仅占 8.3% (1/ 12 )。同时发现 9例急性冠脉综合征患者发生斑块破裂及血栓形成。与稳定性心绞痛的斑块相比较 ,不稳定心绞痛的斑块具有较大的偏心性 (P<0 .0 5 ) ,EEMA、 PA及管腔面积狭窄率明显大于前者 ,具有显著的统计学意义 (P均 <0 .0 0 1) ,不稳定斑块呈现明显的正性重构 ,占 74 .2 % (2 3/ 31) ,而稳定斑块主要表现为负性重构 ,占 75 .0 % (9/ 12 )。结论　 IVUS能够准确地识别 AS不稳定斑块 ,本研究为早期发现不稳定斑块并预测斑块破裂奠定了基础。

Clinical Study on Intravascular Ultrasonic Features of Unstable Atherosclerotic Plaques

Objective:To identify the characteristic features of unstable atherosclerotic plaques with intravascular ultrasound (IVUS).Methods:Forty-three patients underwent coronary angiography (CAG) and IVUS examinations,of which 19 patients were unstable angina,12 were acute myocardial infarction and 12 were stable angina.IVUS was used to analyze the qualities of the plaques and then to measure the external elastic membrane (EEM) area,lumen area(LA),plaque area(PA) and lumen area narrowing (%) at both the lesions and the reference segments in the same vessel,respectively,and lumen eccentricity index and remodeling index were calculated. The characteristic features of unstable atherosclerotic plaques were derived by comparing the results of IVUS in the stable and unstable plaques.Results:There were 73.7%(14/19) patients with unstable angina and 75.0%(9/12)patients with acute myocardial infarction had soft lipid plaques,while patients with stable angina mainly had fibrous and mixed plaques and only 8.3 %(1/12)patients had soft plaques.Nine lesions in acute coronary symdrcme(ACS)patients occurred plaque rupture and thrombosis.There were more eccentric plaques in unstable than in those of the stable group(P<0.05),and EEMA,LA,PA and lumen area narrowing rates in the unstable plaques were larger than those of stable plaques (P<0.001 respectively).Positive remodeling pattern was observed in 74.2%(23/31) unstable plaques while 75%(9/12) stable plaques showed negative remodeling.Conclusions:IVUS can detect unstable atherosclerotic plaques and predict plaques disruption in the early stage of atherosclerosis.