A randomised controlled trial of FFR targeted PCI (Target FFR Study)
Research type
Research Study
Full title
How often can optimal post percutaneous coronary intervention (PCI) fractional flow reserve (FFR) results be achieved?:a randomised controlled trial of FFR targeted PCI (Target FFR Study)
IRAS ID
223780
Contact name
Keith G. Oldroyd
Contact email
Sponsor organisation
Golden Jubilee Foundation
Duration of Study in the UK
2 years, 0 months, 1 days
Research summary
Research Summary:
Cardiology doctors often use a blood flow measurement technique known as Fractional Flow Reserve (FFR) to help decide when a person needs treatment of their coronary artery disease with a stent (a small metallic tube that stretches open a narrowing in a blood vessel). There is evidence to suggest that measuring FFR after stenting could help achieve better final FFR results and potentially better outcomes for patients. Using FFR technology after stenting can help us understand why a result is below target and identify ways to improve it where that occurs. There are additional costs involved though and it isn't clear just how often it is even possible to obtain the target for an optimal post stent FFR result. This uncertainty means it is currently difficult to recommend routine measurements of post stent FFR or to justify the cost involved.
We propose a study to determine how often the target optimal FFR result be achieved in everyday practice using a simple FFR-guided optimisation strategy after stenting. We aim to show that routinely performing blood flow measurements after placement of a stent in a patient's coronary artery and following a simple optimisation strategy when the value is below target can significantly increase the number of patients in whom an optimal post stenting result can be achieved.Lay Summary of Results:
: Cardiology doctors often use a coronary (heart) artery blood flow measurement technique known as Fractional Flow Reserve (FFR) to help determine if a person would benefit from treatment of their coronary artery disease with a stent (a small, tube-shaped metal scaffold that stretches open a narrowing in a blood vessel). Current treatment guidelines recommend that stenting should be considered in arteries with FFR values ≤0.80. Previous research has suggested that performing additional FFR measurements immediately after stenting could help achieve better final FFR results and potentially better outcomes for patients. Using FFR technology after stenting can help us understand why a result remains below target and may also identify ways to improve on it where that occurs. There are additional costs involved though and it was unknown just how often it is even possible to obtain the suggested target optimal FFR result after stenting (a value ≥0.90). This uncertainty meant it was difficult to recommend routine measurements of post-stent FFR or to justify the cost involved without more robust data.The TARGET-FFR randomised controlled trial was developed to determine if a strategy of routinely performing coronary blood flow measurements after placement of a stent and following a simple optimisation protocol if the FFR value was below target would significantly increase the number of people with an optimal post-stent FFR result. 260 people undergoing stenting procedures at the Golden Jubilee National Hospital in Glasgow between March 2018 and November 2019 agreed to participate in the study. Half of the participants were randomly selected to receive the study's optimisation strategy, while the other half underwent standard-of-care stenting followed by blood flow measurements which were not revealed to or acted upon by the treating doctor (control group).
The main findings were that only 32% of people actually achieved the proposed optimal final FFR result of ≥0.90 after stenting. In fact, 29% of people still had an FFR value which remained ≤0.80 despite what looked to be a good result from the stenting procedure. In the optimisation group, 30% of people (40/131) were determined to be suitable for additional measures to try and improve a suboptimal post-stenting FFR result. On average, the extra intervention did improve the FFR values in these arteries but, overall, the FFR-guided optimisation strategy did not significantly increase the final proportion of people with a final FFR ≥0.90 when compared to the control group. It did, however, significantly reduce the proportion of people who had a final FFR value ≤0.80. Stenting procedures which achieved larger improvements in FFR were associated with greater freedom from angina and improved quality of life for participants when re-assessed 3 months later.
In summary, a strategy of routinely measuring coronary artery blood flow after stenting identified that over two-thirds of participants had persistently suboptimal values despite apparently successful procedures. Performing additional intervention on the basis of these results was safe and improved the final blood flow measurements among the worst-affected participants. Larger research trials are required to establish if such strategies can improve long-term clinical outcomes for patients.
REC name
West of Scotland REC 3
REC reference
17/WS/0153
Date of REC Opinion
18 Aug 2017
REC opinion
Further Information Favourable Opinion