左主干冠状动脉病变的血管内超声研究

目的 血管内超声评价非严蕈钙化性左主干病变的形态特点,探讨开口和非开口部位形成狭窄的不同机制.方法 2004年10月至2007年10月,共入选造影确诊或可疑的狭窄病变并行血管内超声检查的153例(开口47例,非开口106例)非严重钙化性左主干病变,定性和定量分析血管内超声图像;负性重构定义为重构指数＜0.95.结果 左主干参考节段平均管腔直径和血管(外弹力膜)直径为(4.1±0.8)mm和(5.3士0.8)mm.开口病变的纤维性、钙化性和软斑块分别为70.2%、19.2%和8.5%,而非开口病变为35.8%、43.4%和3.8%,两者差异有统计学意义(P=0.01).总体来说,31.1%病例的最小管腔面积＜6 mm2,其中开口组29.5%,非开口组31.9%(P=0.87).最小管腔面积在两组相似,但非开口组的斑块面积(13.3±5.4)mm2比(10.8±4.5)mm2,P=0.007]和斑块负荷(61.9%±14.5%比54.8%±15.9%,P=0.020)均显著大于开口组,斑块负荷＞50%的比例更高(84.8%比61.3%,P=0.002).开口病变的重构系数显著低于非开口病变(0.9±0.2比1.0.±0.2,P=0.000),而且负性重构更多见(74.5%和34.9%,P=0.000).logistic回归分析发现,病变部位(OR=4.9,P=0.004)、斑块面积(OR=1.2,P=0.01)和斑块负荷(OR=0.003,P=0.000)是左主干发生重构的独立预测因素.结论 负性重构现象在左主干开口病变中更常见,可能是其狭窄形成的机制之一.狭窄程度不确定的冠状动脉左主干病变需要血管内超声精确评价.

Morphological characteristics of ostial and non-ostial left main corollary artery lesion without heavy calcification determined by intravascular ultrasound imaging

Objective We aimed to assess and compare the morphological characteristics of ostial and non-ostial left main coronary artery (LMCA) lesion without heavy calcification using intravascular ultrasound (IVUS) imaging.Methods Between Oct.2004 and Oct.2007,153 patients with confirmed or suspected coronary artery narrowing in coronary angiography with satisfactory IVUS images and non-heavy calcifieation were inchded in the study (ostial lesions,n=47;non-ostial lesion,n=106).IVUS analysis included plaque composition,external elastic membrane (EEM),lumen,plaque cross-sectional area (CSA),plaque burden (plaque CSA/EEM CSA) at the lesion,proximal and/or distal reference site,and remodeling index (RI,lesion EEM CSA/reference EEM CSA).Negative remodeling was defined as RI＜0.95.Results LMCA mean reference lumen and vessel diameter was 4.1.±0.8 mm and 5.3.±0.8 mm respectively.Incidence of patients with minimum lumen area (MLA＜6.0 mm2) was similar between the two groups (29.5% for ostial Iesions and 31.9% for non-ostial Iesions,P=0.87).There were significantly more fibrous (70.2% vs.35.8%) and soft (8.5%vs.3.8%) plaques while significantly less calcified plaque (1 9.2% vs.43.4%) in patients with ostile lesions compared those with non-ostial lesions (all P＜0.05).Compared to non-ostial lesions,ostial lesion had significant smaller plaque area (10.8.±4.5)mm2 vs.(13.3±5.4) mm2,P=0.007],less plaque burden (54.8%.±15.9% vs.61.9%.±14.5%,P=0.020),smaller RI (0.9±0.2 vs.1.0±0.2,P=0.000) and higher incidence of negative remodeling (74.5% vs.34.9%,P=0.000).Multivariant Logistic regression analysis showed that the site of lesion (ostial or non-estial lesion,Or=4.9,P=0.004),plaque area (OR=1.2,P=0.01) and plaque burden (OR=0.003,P=0.000) were the independent predictors of LMCA remodeling.Conclusion Negative remodcling might be responsible for the development of LMCA ostial narrowing.