Hello everybody, I'm Tatsuya Nakama from Tokyo Bay Medical Center, Japan. Today I'd like to introduce the result of our GRIFFIN study. GRIFFIN study is the relationship between the FFR and the restenosis after the DCB angioplasty for femoral-popliteal regions.

What is the importance behind the GRIFFIN study?

Recently, in the field of the coronary intervention, the relationship between the FFR and indication of the [illegible] also outcome after PCI is frequently reported. However, there is not so much about scientific data of FFR value and DCB angioplasty. So we want to make some of the scientific data about the FFR in the peripheral artery disease and vascular treatment for peripheral artery disease.

So for the stenting strategies, some of the physicians already reported the relationship between the FFR and the result of the angioplasty and the stenting. However, recently stenting is not so mainstream strategy, especially for the femoral-popliteal segment, due to the flexibility of the femoral-popliteal segment. Stenting strategy sometimes makes a problem. The leave-nothing-behind strategy like DCB angioplasty became mainstream and the market share is gradually increasing.

So in these studies we evaluate the result of the DCB angioplasty with the FFR value. DCB angioplasty, as you know, includes a much amount of the problem like impossible to control the recoil and also don't have enough ability to prevent the dissections. They don't have ability to repair the dissections because it's only balloon-based strategy. Therefore, it sometimes fails. But there is no objective evaluation system about the angioplasty failure, DCB angioplasty failure. We mainly evaluate it using only angiography.

It's a very subjective finding. For example, this form classification is frequently used but is very subjective and not so much scientific data about the relationship between the [illegible] classification and result of the DCB angioplasty. We really need a very objective, scientifically evaluated definition about the angioplasty failure. We thought FFR value is directly evaluated through disturbance about the, of course before and after the angioplasty. Therefore, evaluation of the FFR after the angioplasty may directly related to the result of the angioplasty itself. Therefore, we tried to start the previous studies evaluation of the relationship between the FFR and outcome after DCB angioplasty.

What was the study design and patient population?

The study is a prospective multi-centre study. It was held in between January to December 2023. Unfortunately, the number is not huge. Total 126 case patients were enrolled in this GRIFFIN study. The inclusion criteria is Rutherford 2 to 4. Rutherford 5 and 6 tissue loss patient is excluded from these studies. Only De Novo FP lesions were included. After the convention of angioplasty, clear angioplasty failure patients like [illegible] stenosis over 50% angiography or angiographically clear severe dissection, it means type D dissection with flow delay were excluded.

After the evaluations, a total of 103 case patients were enrolled, finally enrolled, and [illegible] were performed. Total 103 patients. We classified into the patient between the two groups: restenosis cases and non-restenosis cases. The definition of restenosis is defined as PSVR over 2.4 by duplex ultrasound or [illegible] stenosis over 50% on angiography and decrease in ABI level of 0.2. Then we try to compare the FFR value just after the DCB angioplasty and instance of the restenosis on 12 months.

What were the key outcomes?

As we expected there is a significant difference between the FFR values between the restenosis patient and the non-restenosis patient. The restenosis patient showed significantly lower FFR values: 0.85. And non-restenosis cases were significantly higher FFR value: 0.96. It means higher FFR value showed non-restenosis. It's very easy to understand. And after the multiple rate analysis, FFR value itself is clearly visualised as an independent predictor of the restenosis.

Where no restenosis predictor of the [illegible] stenosis and dissection grade is not associated to the restenosis in this study because super severe dissection over type D and significant restenosis cases over 50% were excluded. Then we tried to evaluate the cut-off value, cut-off FFR values of the restenosis after the DCB angioplasty. We describe the ROC curve using this data and finally 0.92 is a very good cut-off value for the restenosis. It was pointed at. P-value is 0.0003. As you can see, if we classified the [illegible] using this 0.92 FFR values, over 0.92 cases will show only 6% restenosis. However, if the FFR value is lower than 0.92, as you can see, 33% restenosis were observed. This is quite remarkable findings.

Were there any surprising or unexpected results?

Actually, this is a not so big, huge number study. Therefore, very unexpected results and amazing results are not observed. But interesting point is this 0.92 FFR cut-off value is clearly similar to the previously reported FFR cut-off value for the drug-eluting stent, restenosis after drug-eluting. It's quite an interesting finding.

How should these findings impact clinical practice?

It’s very clear, after the DCB angioplasty, we evaluate only the result of the DCB angioplasty operated only with angiography. It's quite subjective findings. As already reported, the evaluation of the dissection grade and the stenosis, it means result of angioplasty is very, the decision is very heterogenetic.

Many physicians have their opinions. It's very difficult to find clear results. However, if we use this FFR values, evaluation of the FFR after DCB angioplasty we can clearly find that this angioplasty is fair or not, easily expected clinical outcomes. Therefore, use of the FFR value is significantly useful in a daily clinical practice.

What are the next steps?

Thank you very much. This is only a small number of studies and actually so hyperlinear technique. In this study, we use probably 30 [illegible], but many of this kind of technique is not fully established in huge trials. Therefore, the next step is more and also the FFR value and some of the dissection grade everything is not evaluated with only on site.

Therefore, more controlled, collaborative, adjudicated and also a much number of patient study, maybe a reason to evaluate this kind of reported FFR value. And if possible a randomized control trial may be next step to establish the action result. For example, if after the angioplasty, state-based strategy versus DCB strategy or another kind of trial may be a reasonable step.