Original Research
The Use and Efficacy of FFR-CT: Real-World Multicenter Audit of Clinical Data With Cost Analysis

https://doi.org/10.1016/j.jcmg.2023.02.005Get rights and content

Abstract

Background

Fractional flow reserve–computed tomography (FFR-CT) is endorsed by UK and U.S. chest pain guidelines, but its clinical effectiveness and cost benefit in real-world practice are unknown.

Objectives

The purpose of this study was to audit the use of FFR-CT in clinical practice against England’s National Institute for Health and Care Excellence guidance and assess its diagnostic accuracy and cost.

Methods

A multicenter audit was undertaken covering the 3 years when FFR-CT was centrally funded in England. For coronary computed tomographic angiograms (CCTAs) submitted for FFR-CT analysis, centers provided data on symptoms, CCTA and FFR-CT findings, and subsequent management. Audit standards included using FFR-CT only in patients with stable chest pain and equivocal stenosis (50%-69%). Diagnostic accuracy was evaluated against invasive FFR, when performed. Follow-up for nonfatal myocardial infarction and all-cause mortality was undertaken. The cost of an FFR-CT strategy was compared to alternative stress imaging pathways using cost analysis modeling.

Results

A total of 2,298 CCTAs from 12 centers underwent FFR-CT analysis. Stable chest pain was the main symptom in 77%, and 40% had equivocal stenosis. Positive and negative predictive values of FFR-CT were 49% and 76%, respectively. A total of 46 events (2%) occurred over a mean follow-up period of 17 months; FFR-CT (cutoff: 0.80) was not predictive. The FFR-CT strategy costs £2,102 per patient compared with an average of £1,411 for stress imaging.

Conclusions

In clinical practice, the National Institute for Health and Care Excellence criteria for using FFR-CT were met in three-fourths of patients for symptoms and 40% for stenosis. FFR-CT had a low positive predictive value, making its use potentially more expensive than conventional stress imaging strategies.

Section snippets

Methods

We undertook a multicenter audit of FFR-CT performed as part of the ITP program in England between April 2018 and March 2021. Cardiologists and radiologists from hospital trusts in England using FFR-CT were invited to participate (Supplemental Table 1). Because this study was a clinical audit involving a retrospective review of observational data, it was exempt from the need for ethical approval. However, the participating centers registered the project with their quality and safety

Results

Twelve hospital trusts in England contributed to this study, with 2,298 CCTA studies (10.9%) sent for FFR-CT analysis. The number of cases contributed by each center, the time over which the scans were performed, and the total number of CCTAs performed during the same period are shown in Supplemental Table 1.

Baseline clinical and imaging data are shown in Table 1. The mean age of the patients was 61.4 ± 10.0 years (range: 20-91 years), and 62% were male.

Discussion

This observational overview of real-world clinical practice in England reveals that, against the recommendations made by NICE, a quarter of CCTA patients referred for FFR-CT did not have stable chest pain and only 40% had stenosis of uncertain functional significance. Moreover, the PPV of FFR-CT was as low at 33% to 50%, depending on the range of CCTA stenosis considered. Cost analysis suggests that the use of FFR-CT is more expensive than stress imaging alternatives.

Based on the available

Conclusions

To our knowledge, this is the first multicenter audit of the use of FFR-CT against national clinical standards. We found that of the 11% of CCTAs analyzed for FFR-CT, 23% did not have stable chest pain, and 60% did not have stenosis of uncertain significance (50%-69%). The PPV and NPV of FFR-CT in real-world practice were lower than values obtained from published trials, and there was no outcome benefit. Cost analysis revealed that the use of FFR-CT may be more expensive than stress imaging

Funding Support and Author Disclosures

The authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Acknowledgments

The authors are grateful to the British Association of Cardiologists of Indian Origin, who supported this audit. The authors acknowledge the contribution of Paul Bassett for statistical analysis and that of Ana Duarte, Research Fellow at the Centre of Health Economics, University of York, United Kingdom, for the health economic analysis.

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