血管内超声显像在造影无显著狭窄病变的急性冠脉综合征中的应用

目的探讨血管内超声显像(IVUS)在冠状动脉造影无显著狭窄病变的急性冠状动脉综合征的病变检测和指导治疗中的应用价值.方法选取临床诊断急性冠状动脉综合征患者21例,4例为急性Q波性心肌梗死,3例为非Q波性心肌梗死,14例为不稳定型心绞痛,所有病例经冠状动脉造影主要冠脉未见直径狭窄>60%的病变.对靶血管(LAD 17例,RCA 3例,LCX 1例)行IVUS检查.结果 21例21处病变中14例(66.7%)为软斑块,2例(9.5%)为纤维斑块,4例(19.0%)为钙化斑块,1例(4.8%)为混合型斑块;共19例(90.5%)为偏心性斑块;13例(61.9%)正性重构,8例(38.1%)负性重构;重构指数为1.02±0.10(￣x±s).21例患者中有5例发现有斑块破裂,占23.8%;2例发现血栓,占9.5%.面积狭窄率(斑块负荷)范围从43.0%至79.1%,平均为70.0%±8.8%.病变处最小管腔直径(MLD)为(2.29±0.50) mm.IVUS测得的直径狭窄率、面积狭窄率、最小管腔面积和参照血管直径均大于定量冠状动脉造影所测得的数值(P均<0.05).根据IVUS检查结果,15例进行了血运重建术(1例冠脉搭桥术,14例支架植入术).结论在冠状动脉造影无显著狭窄病变的急性冠状动脉综合征病人中,血管内超声检查有助于明确病变的程度、性质并指导治疗方案的选择,病变的偏心性和正性重构可能是造成冠脉造影低估病变程度的主要原因.

Intravascular ultrasound imaging in acute coronary syndrome without angiographically significant stenosis

Objective To assess the value of intravascular ultrasound imaging (IVUS) in patients diagnosed as acute coronary syndrome but without significant stenosis by angiography. Methods Twenty-one patients (male 13) clinically diagnosed as acute coronary syndrome was enrolled in this study. Among them, 4 patients had acute Q-wave myocardial infarction, 3 were non-Q-wave myocardial infarction, 14 suffered from unstable angina. All the patients underwent coronary angiography and no significant stenosis (diameter stenosis >60%) was found in three main vessels (LAD,RCA and LCX). IVUS was performed in the target vessels. Results A total of 21 lesions of 21 patients were examined by IVUS. 14 (66.7%) lesions were soft plaque, 2 (9.5%) were fibrous plaque, 4 (19.0%) were calcified plaque and one (4.8%) was mixed plaque. Most of the plaque (19/21, 90.5%) were eccentric. Positive remodeling was found in 13 (61.9%) lesions and negative remodeling in 8 (38.1%) lesions with mean remodeling index of 1.02±0.10. Mean area stenosis (plaque burden) was 70.0±8.8% (43.0% to 79.1%)and the minimal lumen diameter was (2.29 ±0.50) mm. The diameter stenosis, area stenosis, minimal lumen area and the reference diameter measured by IVUS were larger than those measured by quantitative coronary angiography (all P<0.05). Based on the IVUS finding, 15 patients received revascularization treatment with one bypass surgery and 14 coronary stenting. Conclusion In patients with acute coronary syndrome and no angiographically significant stenotic lesions, IVUS may be useful to precisely assess the severity of the stenosis, the characteristics of the lesion and to enhance the decision making for the treatment. The eccentricity and negative remodeling in the lesion site was possibly the main course of the underestimation by the coronary angiography.