Fractional Flow Reserve and Intravascular Ultrasound in Evaluating Intermediate Coronary Lesions

Both physiologic information from fractional flow reserve (FFR) and anatomical information from intravascular ultrasound (IVUS) in assessing intermediate coronary stenotic lesions are useful. Functional significance of a coronary stenosis is determined by both the severity of a stenosis and the amount of myocardium supplied. Therefore, when the functional significance of a lesion is assessed by lumen area measured by IVUS, different criteria should be applied according to lesion location and anatomical variations of the coronary artery. However, previous studies included only patients with proximal lesions or small vessel disease, and the sample sizes were too small to assess these differences. In a recent study, the investigators have shown that optimal IVUS criteria defining the functional significance (FFR \< 0.8) of intermediate coronary stenoses is different according to their locations of the coronary tree. Herein, the investigators performed this study to validate the our results and to generalize the IVUS criteria defining functional significance of intermediate coronary stenosis in a different location of coronary tree in a larger sample size.