Evaluation of cardiac CT-FFR
Research type
Research Study
Full title
The evaluation of Fractional Flow Reserve computed from CT images
IRAS ID
234418
Contact name
Balazs Ruzsics
Contact email
Sponsor organisation
Royal Liverpool and Broadgreen University Hospitals NHS Trust
ISRCTN Number
ISRCTN00000000
Duration of Study in the UK
0 years, 11 months, 30 days
Research summary
Coronary CT angiography (CTCA) is a non-invasive and hence safer alternative to invasive coronary angiography (dye injection into heart arteries) for visualisation of blood flow to the heart. CTCA is well-established in clinical practice for assessment of chest pain (coronary artery disease). Standard CTCA allows visualisation of narrowings in heart arteries. Where narrowings are mild, tablet treatment is used and where severe, stents or bypass surgery is usually needed. However where narrowings are moderate/intermediate, it can be difficult to assess whether the narrowing actually causes significantly reduced flow and hence ischaemia (suboptimal blood flow to heart muscle).
Ischaemia testing is then needed and is performed using non-invasive stress tests (exercise heart and assess blood flow using cardiac-MRI [stress-CMR], stress-echocardiography, stress nuclear imaging), or with FFR (Fractional Flow Reserve). FFR allows ischaemia assessment by measuring the difference in pressure which is proportional to flow across a narrowing. Typically this is done invasively with a wire in the artery (pressure wire, 'invasive-FFR'). The new technique of CT-FFR allows this to be done offline from routinely-acquired non-invasive CTCA images. CT-FFR is NICE-approved and shows good correlation with the gold standard of invasive-FFR.
(A). There is no published data comparing CT-FFR against non-invasive ischaemia stress tests. We will correlate CT-FFR ischaemia assessment versus the gold-standard non-invasive method of stress-CMR to further assess the robustness and accuracy of CT-FFR.
(B). In patients with stents, metal in the stent makes visual assessment of narrowings and hence ischaemia within the stent difficult and potentially non-diagnostic due to artefact (technical issues due to metal brightness). CT-FFR does not require visual assessment of the artery lumen and may improve analysis in difficult to assess patients such as those with stents. We will compare CT-FFR with standard visual assessment of stents on CTCA for significant narrowing (ischaemia).
REC name
East Midlands - Nottingham 1 Research Ethics Committee
REC reference
17/EM/0399
Date of REC Opinion
11 Oct 2017
REC opinion
Favourable Opinion