Non-invasive physiological assessment of coronary artery obstruction on coronary computed tomography angiography

Abstract

Computed tomography-derived fractional flow reserve (CT-FFR) enhances the specificity of coronary computed tomography angiography (CCTA) to that of the most specific non-invasive imaging techniques, while maintaining high sensitivity in stable coronary artery disease (CAD). As gatekeeper for invasive coronary angiography (ICA), use of CT-FFR results in a significant reduction of negative ICA procedures and associated costs and complications, without increasing cardiovascular events. It is expected that CT-FFR algorithms will continue to improve, regarding accuracy and generalisability, and that introduction of new features will allow further treatment guidance and reduced invasive diagnostic testing. Advancements in CCTA quality and artificial intelligence (AI) are starting to unfold the incremental diagnostic and prognostic capabilities of CCTA's attenuation-based images in CAD, with future perspectives promising additional CCTA parameters which will enable non-invasive assessment of myocardial ischaemia as well as CAD activity and future cardiovascular risk. This review discusses practical application, interpretation and impact of CT-FFR on patient care, and how this ties into the CCTA 'one stop shop' for coronary assessment and patient prognosis. In this light, selective adoption of the most promising, objective and reproducible techniques and algorithms will yield maximal diagnostic value of CCTA without overcomplicating patient management and guideline recommendations.

Keywords: Artificial intelligence; CT-derived fractional flow reserve; Computed tomography angiography; Coronary artery disease; Myocardial ischaemia.

Fig. 1

Infographic: Suggested diagnostic approach using CCTA and CT-FFR as gatekeepers for ICA in clinical management and cardiovascular risk modification. PTP pre-test probability, CAD-RADS coronary artery disease—reporting and data system, LM left main, LAD left anterior descending, HRP high-risk plaque, P3–P4 plaque burden severe-extensive, ICA invasive coronary angiography, FFR fractional flow reserve, iFR instantaneous wave-free ratio, CT-FFR computed tomography-derived fractional flow reserve, RFM risk factor modification

Fig. 2

Example of a patient with a an intermediate coronary stenosis in the left anterior descending artery (LAD) with b corresponding CT-FFR analysis positive for ischaemia and c subsequent invasive coronary angiography, during which revascularisation of both focal stenoses was performed. RCA right coronary artery, LCx left circumflex artery

Fig. 3

Example of a patient with a an intermediate coronary stenosis in the left anterior descending artery (LAD) with b corresponding CT-FFR analysis negative for ischaemia. No invasive coronary angiography was performed. Please note that the CT-FFR value decreases along all three coronary vessels, despite absence of other focal stenoses