血管内超声结合压力导丝对冠状动脉临界病变的判断价值

目的探讨血管内超声(IVUS)指标结合压力导丝评价冠状动脉临界病变的价值。方法 42例患者冠状动脉造影(CAG)显示临界病变(直径狭窄率40%-70%)56处,用压力导丝测定其心肌血流储备分数(FFR),IVUS测定最小管腔面积(MLA)、血管外膜面积计算面积狭窄率。以FFR<0.75为界值,采用受试者工作特征曲线(ROC)选择IVUS指标的切点。结果 56处血管病变的IVUS测得面积狭窄率为(75.0±3.8)%,MLA(3.83±0.37)mm2。压力导丝测得FFR为0.78±0.03,29处病变低于界限值(FFR<0.75),均显著低于CAG正常对照组(FFR为0.95±0.03)。IVUS面积狭窄率与FFR呈负相关(r=-0.72,P<0.01)。以FFR<0.75为界值,根据ROC分析,面积狭窄率≥75%、MLA≤3.0mm2为切点灵敏性分别为94%、85%,特异性73%、66%。结论IVUS测定的面积狭窄率≥75%和MLA≤3.0mm2与FFR<0.75密切相关,可据此判断临界病变的血管功能,指导临床处理策略的制定。

Value of intravascular ultrasound combined with pressure wire in evaluating intermediate coronary artery stenosis

Objective To investigate the value of intravascular ultrasound combined with pressure wire in evaluating intermediate artery stenosis.Methods Fourty-two patients had 56 lesions of intermediate coronary lesions(40% to 70% stenosis) diagnosed by coronary artery angiography(CAG).Myocardial fractional flow reserve(FFR) was determined by pressure wire,and minimal lumen area(MLA) and area stenosis rate at the lesion region were determined by intravascular ultrasound(IVUS).Optimal IVUS criteria for functionally significant stenoses(FFR<0.75) were assessed through receiver operating characteristic(ROC) curve analysis.Results The area stenosis rate was(75.0±3.8)%,MLA was(3.83±0.37) mm2,FFR was 0.78±0.03,and FFR<0.75 in 29 lesions.All lesions were significantly lower than those in control group with normal artery(FFR=0.95±0.03).Area stenosis rate showed a significant negative correlation with FFR(r=-0.72,P<0.01).MLA had a significant positive correlation with FFR(r=0.60,P<0.01).By ROC analysis,IVUS area stonosis rate≥75%(sensitivity 91%,specificity 76%),MLA≤3.0 mm2(sensitivity 87%,specificity 64%) were confirmed the optimal cut-off values consistent with FFR<0.75.Conclusion IVUS parameters(area stonosis rate and MLA) are closely correlated to FFR<0.75,which may be used to determine the functional significance of the lesions in patients with intermediate coronary artery stenosis.