血管内超声显像指标对冠状动脉中度狭窄病变功能意义的判断价值

Intravascular ultrasound criteria for the assessment of the functional significance of intermediate coronary artery stenosis

目的:评估血管内超声显像(intravascularultrasound,IVUS)测定的指标对冠状动脉中度狭窄病变功能意义的判断价值。方法:46支冠状动脉造影(coronaryarteryangiography,CAG)显示中度狭窄(直径狭窄率40%～60%)的冠状动脉,压力导丝测定心肌血流储备分数(myocardialfractionalflowreserve,FFRmyo),IVUS测定面积狭窄率及最小管腔面积。以FFRmyo<0.75为界限值,采用受试者工作特征曲线(receiveroperatingcharacteristic,ROC)选择IVUS测量的每个指标的截断点。结果:46支血管病变的直径狭窄率(49±11)%,FFRmyo为(0.83±0.15),显著低于正常组(FFRmyo为0.97±0.02)。14处(30%)病变低于界限值(FFRmyo<0.75)。IVUS面积狭窄率与FFRmyo呈负相关(r=-0.68,P<0.001)。以FFRmyo<0.75为界限值,根据ROC分析,面积狭窄率≥65%为截断点,灵敏度=100%,特异性=72%。最小管腔面积与FFRmyo呈正相关(r=0.63,P<0.001),以最小管腔面积≤4mm2为截断点,灵敏度=93%,特异性=77%。结论:IVUS测定的面积狭窄率≥65%、最小管腔面积≤4mm2,能较准确地判断中度狭窄病变的功能意义。

Objective：to evaluate the role of intravascular ultrasound（IVUS） in the assessment of functional significance of the intermediate lesion. Method： In 46 lesions of intermediate severity（ e. g, 40% to 60% diameter stenosis）we assessed 1. by pressure wire：myocardial fractional flow reserve（FFRmyo, index of functional significance）, and 2. by IVUS： minimal lumen cross-sectional area（MLA） and percent area stenosis at the lesion site. Receiver operating characteristic（ROC） curve analysis was performed to establish the best cut-off values of IVUS indexes（ i. e., MLA and percent area stenosis ） that were most predictive of FFRmyo 〈 0. 75. Result： FFRmyo in 46 lesions of angiographic intermediate stenosis （49 ± 11 ）% was significantly lower than it was in angiographic normal artery （0.83 ± 0. 15 vs. 0. 97 ± 0. 02, P 〈 0. 01 ）, Fourteen lesions （30%） were functionally critical （ e. g, FFRmyo 〈 0. 75 ）. By regression analysis, percent area stenosis had a significant inverse correlation with FFRmyo （ r = - O. 68, P 〈 0 .O1 ） .MLA showed a significant positive relation with FFPmyo （ r = 0. 63, P 〈 0. 01 ）. By ROC analysis, we identified a IVUS area stonosis ≥ 65 % （sensitivity 100%, specificity 72 % ）, a minimal lumen cross-sectional area 4 mm^2 （ sensitivity 93 %, specificity 77 % ） to be the best cut-off values to fit with FFRmyo 〈 0. 75. Conclusion： IVUS area stenosis ≥ 65% and minimal lumen cross-sectional area ≥ 4 mm^2 reliably identified functionally critical intermediate coronary stenosis.