Less invasive fractional flow reserve measurement from 3-dimensional quantitative coronary angiography and classic fluid dynamic equations

Abstract

The aim of this study was to develop a simplified model of FFR calculation (FFR sim ) derived from three-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.The 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 (FFR sim ) was assessed by comparing the results with standard invasive FFR measurements (FFR meas ) in 68 vessels with a single stenosis. We found a strong correlation between the FFR sim and the FFR meas (r=0.86, p<0.0001). The sensitivity and specificity for predicting the abnormal FFR of ≤0.80 (indicating haemodynamically significant stenosis) were 90% and 100%, respectively. The area under the curve (AUC) was 0.96. To achieve 100% negative and positive predictive values we defined the FFR sim >0.88 and the FFR sim ≤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 FFR sim .

Computerised Methodologies for Non-Invasive Angiography-Derived Fractional Flow Reserve Assessment: A Critical Review

“…FFR sim is an angiography-derived FFR methodology that is based on 3D-QCA and classic fluid dynamics equations without using finite element analysis [21].…”

“…Finally, this allows calculation of FFR sim which is defined as Pd/Pa across as stenosis. Tar et al studied 68 vessels with single-vessel stenosis where FFR sim shows strong correlation with invasive FFR (r � 0.86, p < 0.0001) [21]. e sensitivity and AUC of FFR sim to detect haemodynamically significant lesions (FFR < 0.80) were 0.90 and 0.96, respectively.…”

A hyperaemiás és a nonhyperaemiás intrakoronáriás nyomásarányok együttes értékelésének diagnosztikus jelentősége

“…Mivel ez a legkevésbé invazív és legolcsóbb módszer, így amennyiben további tanulmányok helyen lesz javasolható a képalapú (image based FFR) -számíthatjuk ki bizonyos pontossággal az éren kialakuló nyomásesést. Az eddigi eredmények szerint ezek a kevésbé invazív módszeren alapuló képalapú FFR-értékek jól közelítik az invazív módszerrel mért FFR-t (28)(29)(30)…”

Hyperemic contrast velocity assessment improves accuracy of the image-based fractional flow reserve calculation

“…In our previous study, on a less invasive FFR measurement, we proposed a new simplified model developed for the estimation of FFR [2]. It was found that this method was suitable for characterizing every single intermediate stenosis with an especially good positive predictive value; furthermore, the calculations only require a simple MS Excel sheet for the input of the hyperemic flow velocity values and the data of the three-dimensional coronary reconstruction.…”

“…The purpose of this present study was to perform a retrospective analysis on the cases of the previous study [2] to assess the accuracy of FFR calculations using the fixed hyperemic contrast flow, the resting frame count, and the hyperemic frame count data.…”