Diagnostic performance of virtual fractional flow reserve derived from routine coronary angiography using segmentation free reduced order (1-dimensional) flow modelling

Kevin Mohee; Jonathan P Mynard; Gauravsingh Dhunnoo; Rhodri Davies; Perumal Nithiarasu; Julian P Halcox; Daniel R Obaid

doi:10.1177/2048004020967578

Diagnostic performance of virtual fractional flow reserve derived from routine coronary angiography using segmentation free reduced order (1-dimensional) flow modelling

JRSM Cardiovasc Dis. 2020 Nov 5:9:2048004020967578. doi: 10.1177/2048004020967578. eCollection 2020 Jan-Dec.

Authors

Kevin Mohee¹, Jonathan P Mynard^{2

3

4

5}, Gauravsingh Dhunnoo¹, Rhodri Davies¹, Perumal Nithiarasu⁶, Julian P Halcox⁷, Daniel R Obaid⁷

Affiliations

¹ Department of Cardiology, Swansea Bay University Health Board, Morriston Hospital, Swansea, UK.
² Heart Research, Murdoch Children's Research Institute, Parkville, VIC, Australia.
³ Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia.
⁴ Department of Biomedical Engineering, The University of Melbourne, Parkville, VIC, Australia.
⁵ Department of Cardiology, The Royal Children's Hospital, Parkville, VIC, Australia.
⁶ Swansea University School of Engineering, Bay Campus, Swansea, UK.
⁷ Swansea University Medical School, Swansea, UK.

Abstract

Introduction: Fractional flow reserve (FFR) improves assessment of the physiological significance of coronary lesions compared with conventional angiography. However, it is an invasive investigation. We tested the performance of a virtual FFR (1D-vFFR) using routine angiographic images and a rapidly performed reduced order computational model.

Methods: Quantitative coronary angiography (QCA) was performed in 102 with coronary lesions assessed by invasive FFR. A 1D-vFFR for each lesion was created using reduced order (one-dimensional) computational flow modelling derived from conventional angiographic images and patient specific estimates of coronary flow. The diagnostic accuracy of 1D-vFFR and QCA derived stenosis was compared against the gold standard of invasive FFR using area under the receiver operator characteristic curve (AUC).

Results: QCA revealed the mean coronary stenosis diameter was 44% ± 12% and lesion length 13 ± 7 mm. Following angiography calculation of the 1DvFFR took less than one minute. Coronary stenosis (QCA) had a significant but weak correlation with FFR (r = -0.2, p = 0.04) and poor diagnostic performance to identify lesions with FFR <0.80 (AUC 0.39, p = 0.09), (sensitivity - 58% and specificity - 26% at a QCA stenosis of 50%). In contrast, 1D-vFFR had a better correlation with FFR (r = 0.32, p = 0.01) and significantly better diagnostic performance (AUC 0.67, p = 0.007), (sensitivity - 92% and specificity - 29% at a 1D-vFFR of 0.7).

Conclusions: 1D-vFFR improves the determination of functionally significant coronary lesions compared with conventional angiography without requiring a pressure-wire or hyperaemia induction. It is fast enough to influence immediate clinical decision-making but requires further clinical evaluation.

Keywords: Coronary imaging: angiography/ultrasound/Doppler/CC; cardiovascular imaging agents/techniques; catheter-based coronary interventions: stents.