The relation between fractional flow reserve and vascular dilation ration in predicting myocardial ischemia

Abstract Introduction Fractional flow reserve (FFR) is the gold standard for evaluation of myocardial ischemia but requires invasive pressure wire. Laplace’s Law states that the tension in the wall if a vessel is proportional to the pressure inside the vessel and its radius. The vascular dilation ratio (VDR) is the degree of dilation in the vessel proximal to the stenosis. Our aim was to test VDR using routine angiographic images and its correlation with FFR. Method Patients who performed coronary angiography with FFR were enrolled. After the images were reconstructed using ciunterpint and binarization analysis, VDR was calculated using the ratio of the maximal diameter minus the minimal diameter divided by the minimal diameter after contrast injection. Lesion’s characteristics, including adenosine dose and FFR were collected. The lesions were divided into two groups based on their FFR values: FFR≤ 0.8 and FFR >0.8. Result A total of 31 patients were enrolled, with a mean age 62.0 ± 13.3 years, and 19 of them were male). Of the 31 de-novo lesions analyzed, 23 were located in the left anterior descending artery, 4 in left circumflex artery, and 4 in right coronary artery. VDR was significantly higher in the group of lesions with FFR≤ 0.8, compared to the group with FFR >0.8 (P<0.01) (Table 1). The negative correlation coefficient between VDR and FFR was -0.92 (Figure 1). Conclusion The high negative correlation between VDR and FFR suggests that VDR could be a useful pre-FFR test for evaluating the severity of myocardial ischemia. Further studies with larger sample sized are warranted to confirm these finding.Table 1Figure 1