Feasibility of CT Angiography-derived Kinetic Energy of Coronary Flow to Improve the Detection of Hemodynamically Significant Coronary Stenosis.

Purpose: To investigate whether coronary flow kinetic energy has incremental value over simulated fractional flow reserve (sFFR) in diagnosing hemodynamically significant stenosis assessed with coronary CT angiography and invasive fractional flow reserve (FFR).

Materials And Methods: This single-center retrospective study included 113 patients (mean age, 68 years ± 9 [SD]; 80 men) who underwent coronary CT angiography showing intermediate stenosis (30%-70% stenosis) and subsequent invasive FFR between December 2015 and March 2020. Kinetic energy was calculated using proximal coronary diameter and myocardial mass of the stenotic region. A mesh-free simulation was performed to calculate the sFFR. Invasive FFR of 0.80 or less indicated hemodynamically significant stenosis. Models using diameter stenosis, kinetic energy, and sFFR were compared by analyzing the receiver operating characteristic curve.

Results: Of the 144 vessels evaluated, 53 vessels (37%) had hemodynamically significant stenosis. Kinetic energy of vessels with significant stenosis was higher than that of vessels with nonsignificant stenosis (79 mJ/kg [IQR, 58-104 mJ/kg] vs 36 mJ/kg [IQR, 23-59 mJ/kg]; < .001). Multivariable analysis including diameter stenosis and sFFR showed that kinetic energy (per 20 mJ/kg; odds ratio, 1.92; 95% CI: 1.37, 2.95; < .001) was a predictor of hemodynamically significant stenosis. Adding kinetic energy to diameter stenosis and sFFR improved the area under the receiver operating characteristic curve from 0.89 (95% CI: 0.84, 0.95) to 0.93 (95% CI: 0.89, 0.97) ( = .04).

Conclusion: Kinetic energy had incremental value over sFFR in detecting hemodynamically significant stenosis assessed with invasive FFR. Coronary CT Angiography, Coronary Arteries, Fractional Flow Reserve, Kinetic Energy, Cardiac © RSNA, 2022.