Visualization of the improvement of myocardial perfusion after coronary intervention using motorized fractional flow reserve pullback curve

This study aimed to evaluate the feasibility and utility of using motorized pullback of the pressure guidewire to provide a graphic assessment and prediction of the benefits of coronary intervention. Fractional flow reserve (FFR) measurements were performed with motorized pullback imaging in 20 patients who underwent successful percutaneous coronary intervention (PCI) of the left anterior descending artery. Physiological lesion length (PLL) was calculated using frame counts to determine stent length. FFR area was calculated by integrating the FFR values recorded during pullback tracing (FFRarea). The percentage increase in FFR area (%FFRarea) was defined as the ratio of the difference between the pre- and post-intervention FFRarea to the total frame count. The average FFR values were enhanced following PCI, from 0.64 to 0.82, and the median value of the difference between pre- and post-interventional FFR values (D-FFR) and %FFRarea were 0.13 and 10.6%, respectively. The %FFRarea demonstrated a significant positive correlation with D-FFR (R 2, 0.61; p < 0.01). PLL tended to be longer and the %FFRarea was smaller in lesions with a gradual pressure-drop pattern than those with an abrupt pressure-drop pattern (35.37 vs. 20.40 mm, p = 0.07; 5.78 vs. 16.21%, p < 0.05, respectively). Motorized pullback tracing was able to identify the extent and location of stenosis and help in appropriate stent implantation, in addition to visualizing and quantifying the improvement in FFR following PCI.