Aim: Noninvasive fractional flow reserve (NiFFR) is an emerging method for
evaluating the functional significance of a coronary lesion during diagnostic coronary
angiography (CAG). The method relies on the computational flow dynamics and the threedimensional (3D) reconstruction of the vessel extracted from CAG. In the present study,
we sought to evaluate the diagnostic performance and applicability of 2D-based NiFFR.
Methods: In this prospective observational study, we evaluated 2D-based NiFFR in
279 candidates for invasive CAG and invasive fractional flow reserve (FFR). NiFFR
was calculated via two methods: variable NiFFR, in which the contrast transport time
was extracted from the angiographic view, and fixed NiFFR, in which a prespecified
frame count was applied.
Results: The final analysis was performed on 245 patients (250 lesions). Variable
NiFFR had an area under the receiver operating characteristic curve of 81.5%, an
accuracy of 80.0%, a sensitivity of 82.2%, a specificity of 82.2%, a negative predictive
value of 91.4%, and a positive predictive value of 63.6%. The mean difference
between FFR and NiFFR was −0.0244 ±.0616 (p ≤.0001). A pressure wire-free
hybrid strategy was possible in 68.8% of our population with variable NiFFR.
Conclusions: Our 2D-based NiFFR yielded results comparable to those derived from
3D-based software. Our findings should; however, be confirmed in larger trials.
coronary angiography, fractional flow reserve, quantitative coronary analysis, quantitative