冠状动脉左前降支开口部病变的血管内超声观察

Coronary remodeling patterns of ostial left anterior descending artery stenosis: an intravascular ultrasound study

目的 探讨冠状动脉左前降支(LAD)开口部病变的重塑类型。方法 对31例LAD开口部病变(甲组)和24例冠状动脉造影正常的LAD(乙组)进行血管内超声检查。分别于病变远端参照部位及开口部病变处测量血管面积、管腔面积及斑块面积。重塑指数定义为开口部病变处血管面积与病变远端参照部位血管面积的比值。结果 甲组的重塑指数明显小于乙组(0.79±0.19比0.97±0.11,P<0.001)。如定义重塑指数<0.92(乙组平均重塑指数的95％可信区间的下限值)为收缩性重塑,则甲组中81％(25/31)为收缩性重塑。在发生收缩性重塑的病变中,病变处管腔面积的减少54％是由病变处血管收缩所致。病变处管腔面积的减少与血管面积的减少的相关性比病变处管腔面积的减少与斑块面积的增加的相关性更强(r=0.75,P<0.001和r=0.62,P<0.01)。结论 LAD开口部病变以收缩性重塑更常见,收缩性重塑是决定LAD开口部病变狭窄程度的重要因素。

Objective To investigate the coronary remodeling patterns of ostial left anterior descending (LAD) stenosis. Methods A total 31 de novo LAD ostial lesions and 24 angiographically normal LAD ostial were studied with intravascular ultrasound ( IVUS ). Vessel area ( VA) , lumen area (LA) , plaque area (PA) (PA = VA-LA), and plaque burden (PA/VA x 100% ) were measured at LAD ostium and at the distal reference segment. The remodeling index (RI) was calculated as (VA at LAD ostium)/( VA at the distal reference) . Results RI of ostial LAD lesions was significantly smaller than that of normal LAD ostial(0. 79±0. 21 vs. 0. 97±0. 11, P <0. 001). When constrictive remodeling was defined as RI < 0. 92 (lower bound of 95 % confidence interval for normal mean RI) , 81 % ( 25/31) of ostial LAD lesions fitted this definition. In constrictive remodeling group, 54% of luminal narrowing was attributed to paradoxical shrinkage of the vessel. VA reduction correlated with LA reduction more closely ( r = 0. 75, P < 0. 001) than with PA increase(r = 0. 62, P <0. 01) in constrictive remodeling group, allowing for a normal 3% loss of VA at LAD ostium. Conclusions Constrictive remodeling commonly ( 81 %) occurs at ostial LAD lesions and contributes significantly to the development of luminal narrowing.