"Less Invasive" Fractional Flow Reserve Measurement From 3-Dimensional Quantitative Coronary Angiography and Classic Fluid Dynamic Equations

Aims: To develop a simplified model of FFR calculation (FFRsim) deriving from 3-dimensional (3D) coronary angiographic data and classic fluid dynamic equations without using finite element analysis. Methods and results: Intracoronary pressure measurements were performed by pressure wire sensors. Lumens of the interrogated vessel segments were reconstructed in 3D. The coronary artery volumetric flow was calculated based on the velocity of the contrast material. Pressure gradients were computed by classic fluid dynamic equations. The diagnostic power of the simplified computation of the FFR (FFRsim) was assessed by comparing the results with standard invasive FFR measurements (FFRmeas) in 68 vessels with single stenosis. We found a strong correlation between the FFRsim and the FFRmeas (r=0.86, p 0.88 and the FFRsim ≤ 0.8 ranges. In our patient population, these ranges were found in 69% of the cases. Conclusions: According to our simplified model the invasive FFR measurement can be omitted without misclassification in pre-specified ranges of the calculated FFRsim