Background:
Fractional Flow Reserve (FFR) is a method based on the use of a pressure wire - now proven effective to evaluate the hemodynamic impact of a coronary stenosis. However, this technique is invasive. To address this, software packages computing the FFR value based solely on angiography images were developed. These software packages have been validated for chronic coronary syndrome (CCS) but not for every other clinical context. This review summarizes angiography-derived software packages validated for each specific contexts as well as landmark studies and clinical trials supporting the modalities.
Methods:
All Publications found on PubMed were reviewed and 4 angiography-derived software packages were selected: QFRTM by Medis, vFFRTM by Pie Medical Imaging, FFRangioTM by Cathworks and caFFRTM by RainMed. Publications review was based on searching specific contexts validations or use, landmark studies and clinical trials. Specific contexts were then introduced into a table to compare the different software packages validations. Landmark studies and clinical trials were also compared.
Results:
In this review, 218 publications were considered and from those, QFR is the software package with the most validations or with the largest use in different specific contexts with 21 publications that were considered valid for this review, while vFFR arrived second with 9 publications. Regarding the 2 other software packages (FFRangio and caFFR), only 3 publications were found. QFR also has the most patients included among the selected publications (11’940 patients) as compared to vFFR, FFRangio and caFFR (with respectively 2’206, 652 and 554 patients).
Interestingly, the 4 modalities landmark studies i.e. validations in generic context (CCS) vs wire based-FFR have comparable number of patients included: 329 for QFR, 334 for vFFR, 301 for FFRangio, 330 for caFFR.
Regarding clinical trials, QFR is the only modality with a completed and published clinical trial. vFFR and caFFR clinical trials are currently ongoing. Their number of patients included is also comparable: 3847 for QFR, 2228 for vFFR, 2132 for caFFR.
All the software packages have both FDA and CE certification except caFFR which does not have the FDA approval according to the data available Mai 20th 2022.
Conclusion:
For the time being, QFR is the modality with the most upsides: more specific contexts validations and an existing clinical trial published are two decisive arguments but incoming clinical trials could bring arguments for other modalities.
Further validations are however necessary to fully be able to compare these software packages and decide which one to choose when thinking of purchasing one.