冠状动脉重构的血管内超声研究

Investigation of coronary arterial remodeling by intravascular ultrasound

目的应用血管内超声探讨冠状动脉重构的病变特征及其与临床表现的关系。方法39例急性冠脉综合征患者与45例稳定性心绞痛患者进行冠脉造影及血管内超声检查,对病变进行定性和定量测定。包括外弹力膜血管面积(EEMA)、最小血管内膜腔面积、斑块面积、斑块体积及斑块的性状和重构指数,根据血管内超声斑块的性状分为软斑块和硬斑块(包括纤维斑块、钙化斑块和混合斑块)。重构指数(RI)=病变处EEMA/平均参考血管处EEMA。若RI>1.0为正性重构,RI<1.0为负性重构。结果正性重构及负性重构两组年龄、性别及冠心病危险因素等无明显差别,急性冠状动脉综合征的患者更多的表现为正性重构(61.4%vs30.0%,P<0.01)。稳定性心绞痛的患者更多的表现为负性重构(70.0%vs38.6%,P<0.01)。与负性重构相比,正性重构一般狭窄程度较轻,但病变部位的血管面积及斑块面积较大〔(17.8±7.0)vs(13.6±4.9)mm2,(12.2±5.5)vs(9.5±4.8)mm2,P<0.01〕,同时正性重构多为偏心性软斑块,发生钙化的较少。结论正性重构及负性重构的病理特征不同,正性重构病变以软斑块及偏心性斑块多见,冠状动脉重构与临床表现及斑块特征有关。

Objective To investigate the lesion characteristics of coronary remodeling by intravascular ultrasound（IVUS）and to evaluate the relation between coronary remodeling pattern and clinical presentation of coronary heart disease. Methods Eighty four selected patients who underwent coronary angiography and pre-intervention IVUS were analyzed. 39 cases of acute myocardial infarction and unstable angina pectoris were categorized as acute coronary syndrome （ACS）, and 45 cases of stable angina pectoris （SAP） as stable coronary artery disease （CAD）. IVUS was used to measure the external elastic membrane area（EEMA）, minimal luminal area, plaque area（PA）, plaque volume, plaque character and arterial remodeling index. The lesions were classified into soft plaque and hard plaque（including fibrous plaque, calcified plaque and mixed plaque） according to different ultrasound patterns of tissue reflection. The remodeling index（RI）was defined as the ratio of vessel cross sectional area（EEMA） of lesion segment to the mean reference EEMA. Positive remodeling was defined as RI 〉 1.0 and negative remodeling as RI 〈 1.0. Coronary remodeling patterns and plaque morphology of the culprit lesion obtained by IVUS were analyzed in terms of their relation with clinical presentation or angiographic morphology. Results The age, sex and risk factors for eoro nary heart disease （hypertension, diabetes, smoking,hyperlipemia） had no significant differences between negative remodeling and positive remodeling groups（P 〉 0.05） In ACS group, positive remodeling was observed more frequently than in SAP group （61.4 % vs 30. 0 %, P 〈0.01 ）, whereas in SAP group negative remodeling was more frenquently observed than in ACS group（70.0% vs 38.6 %, P〈0.01 ）. Positive remodeling was usually based on mild stenosis （≤50%）, but the EEMA and the PA ware significantly larger in positive remodeling lesion than those in negative remodeling lesionS（17.8±7.0）mm^2 vs （13.6±4. 8）mm^2 , （12.2±5.5） mm^2 vs （9.5±4.8）mm^2 ,P〈0. 01]. In patients with positive remodeling, soft plaque , eccentric plaque with little calcification was most frequent （63. 6%,65.9% respectively）. Conclusion The plaque morphology of the culprit lesion are different between the two kinds of coronary remodeling patterns. The lesion feature in positive remodeling is apparently soft eccentric plaque. These results may reflect the impact of remodeling types and its culprit lesion characteristics of CAD on clinical presentation.