Ben-Dor Itsik, Torguson Rebecca, Deksissa Teshome, Bui Anh B, Xue Zhenyi, Satler Lowell F, Pichard Augusto D, Waksman Ron
Division of Cardiology, Washington Hospital Center, Washington, DC 20010, USA.
Cardiovasc Revasc Med. 2012 May-Jun;13(3):177-82. doi: 10.1016/j.carrev.2011.12.003. Epub 2012 Feb 14.
A fractional flow reserve (FFR) of <0.8 is currently used to guide revascularization in lesions with intermediate coronary stenosis. Whether there is an intravascular ultrasound (IVUS) measurement or a cutoff value that can reliably determine which of these intermediate lesions requires intervention is unclear.
We assessed IVUS measurement accuracy in defining functional ischemia by FFR.
The analysis included 205 intermediate lesions (185 patients) located in vessel diameters >2.5 mm. Positive FFR was considered present at <0.8. IVUS measurements were correlated to the FFR findings in intermediate lesions with 40%-70% stenosis. Fifty-four (26.3%) lesions had FFR<0.8.
There was moderate correlation between FFR and IVUS measurements, including minimum lumen area (MLA) (r=0.36, P<.001), minimum lumen diameter (MLD) (r=0.25, P=<.001), lesion length (r=-0.43, P<.001), and area stenosis (r=-0.33, P=.01). A receiver operating characteristic curve (ROC) identified MLA<3.09 mm(2) (sensitivity 69.2%, specificity 79.5%) as the best threshold value for FFR<0.8. The correlation between FFR and IVUS was better for large vessels compared to small vessels. ROC analysis identified the best threshold value for FFR<0.8 of MLA<2.4 mm(2) [area under curve (AUC)=0.74] in lesions with reference vessel diameters of 2.5-3 mm, MLA<2.7 mm(2) (AUC=0.77) in lesions with reference vessel diameters of 3-3.5 mm, and MLA<3.6 mm(2) (AUC=0.70) in lesions with reference vessel diameters >3.5 mm.
Anatomic measurements of intermediate coronary lesions obtained by IVUS show a moderate correlation to FFR values. The correlation was better for larger-diameter vessels. Vessel size should always be taken into account when determining the MLA associated with functional ischemia.
目前，血流储备分数（FFR）<0.8 用于指导中度冠状动脉狭窄病变的血运重建。尚不清楚是否存在血管内超声（IVUS）测量值或临界值能够可靠地确定哪些中度病变需要干预。
我们评估了IVUS在通过FFR定义功能性心肌缺血方面的测量准确性。
分析纳入了位于直径>2.5 mm血管中的205个中度病变（185例患者）。FFR<0.8被视为阳性。IVUS测量值与狭窄程度为40%-70%的中度病变的FFR结果相关。54个（26.3%）病变的FFR<0.8。
FFR与IVUS测量值之间存在中度相关性，包括最小管腔面积（MLA）（r=0.36，P<0.001）、最小管腔直径（MLD）（r=0.25，P<0.001）、病变长度（r=-0.43，P<0.001）和面积狭窄（r=-0.33，P=0.01）。受试者工作特征曲线（ROC）确定MLA<3.09 mm²（敏感性69.2%，特异性79.5%）为FFR<0.8的最佳阈值。与小血管相比，FFR与IVUS在大血管中的相关性更好。ROC分析确定，在参考血管直径为2.5-3 mm的病变中，FFR<0.8的最佳阈值为MLA<2.4 mm²[曲线下面积（AUC）=0.74]；在参考血管直径为3-3.5 mm的病变中，为MLA<2.7 mm²（AUC=0.77）；在参考血管直径>3.5 mm的病变中，为MLA<3.6 mm²（AUC=0.70）。
通过IVUS获得的中度冠状动脉病变的解剖学测量值与FFR值存在中度相关性。在较大直径血管中相关性更好。在确定与功能性心肌缺血相关的MLA时，应始终考虑血管大小。
