Real-world clinical and cost analysis of CT coronary angiography and CT coronary angiography-derived fractional flow reserve (FFRCT)-guided care in the National Health Service

Abstract

Aim: To quantify the real-world clinical and cost impact of computed tomography (CT) coronary angiography (CTCA)-derived fractional flow reserve (FFR_CT) in the National Health Service (NHS).

Materials and methods: Consecutive clinical CTCA examinations from September to December 2018 with ≥1 stenosis of ≥25% underwent FFR_CT analysis. The Heart Team reviewed clinical data and CTCA findings, blinded to FFR_CT values, and documented hypothetical consensus management. FFR_CT results were then unblinded and hypothetical consensus management re-recorded. Diagnostic waiting times for management pathways were estimated. A per-patient cost analysis for diagnostic certainty regarding coronary artery disease (CAD) management was performed using 2014-2020 NHS tariffs for pre- and post-FFR_CT pathways.

Results: Two hundred and fifty-one CTCAs were performed during the study period. Fifty-seven percent (145/251) had no CAD or stenosis <25%. One study was non-diagnostic. Of the remaining 42% (105/251), two were ineligible for FFR_CT and there was a 5% (5/103) failure rate. FFR_CT led to a change in hypothetical management in 65% (64/98; p<0.001) patients with a functional imaging test cancelled in 17% (17/98) and a diagnostic angiogram cancelled in 47% (46/98). FFR_CT-guided management had a reduced mean time to definitive investigation compared with CTCA alone (28 ± 4 versus 44 ± 4 days; p=0.004). Using the proposed 2020/21 tariff, CTCA + FFR_CT for stenosis ≥50% resulted in a diagnostic pathway £44.97 more expensive per patient than usual care without FFR_CT.

Conclusions: In the real-world NHS setting, FFR_CT-guided management has the potential to rationalise patient management, accelerate diagnostic pathways, and depending on the stenosis severity modelled, may be cost-effective.