Fractional Flow Reserve (FFR) is an ideal tool for cardiologists to make the right decision: Dr Nils P Johnson
Shahid Akhter, editor, ETHealthworld spoke to Dr Nils P Johnson, Associate Professor of Cardiology, University of Texas, Houston, USA to know more about Fractional Flow Reserve (FFR) and how it impacts the decision making process in Intervention cardiology.
Use of FFR Intervention cardiology
One of the biggest challenges that an interventional cardiologist faces is the basic question : which patient needs stents ? It is a technology that is expensive, invasive and is something that stays in the patient’s body for the rest of his/her life. So, making that decision in a correct way and quantifiable way is something that cardiology has struggled with for many decades. Fractional Flow Reserve (FFR) provides the best established objective tool for making that decision, so that we can feel confident that ‘Yes! this patient needed stent’ or ‘No! that patient could be simply treated with medicines.’ It is a tool that is used everyday while I am working in a cath-lab taking care of patients.
Patients come to us as interventional cardiologists, usually through two ways. One way, that they are very sick or having a heart attack and so they show up in a real emergency. In this case, our goal for those patients, is to stop the heart attack and to stabilize things. The other common way that patients come to us is because they are having some kind of symptoms, they are having shortness of breath or they have pains in their chest when they exercise. I would say the strongest reason to use Fractional Flow Reserve (FFR) is a stable patient. The person who has some kind of symptom, the question is weather, is it coming from the heart or is it something that we could make that person feel better by treating it with a stent. That’s where most of the data has come over the last 20-30 years in terms of using Fractional Flow Reserve (FFR). So, that’s really the strongest reason for choosing Fractional Flow Reserve (FFR).
Acceptance of Fractional Flow Reserve (FFR) in the US
One of the ways by which this is measured, is by taking the number of Fractional Flow Reserve (FFR) procedures and dividing it by the number of stents. It’s a simple ratio, but at least it gives us some understanding of how the amount of Fractional Flow Reserve (FFR) usage has changed over time. It’s something that can be compared among countries as well. And countries have published this data. What we see today looking at the US, Australia and countries like Sweden, is that the number is somewhere between 20% and 30% these days. The number though, has really changed in the last 5 years. If you go back, in a lot of those places you will see that, 5 years – 10 years ago it was maybe a third or quarter or less of what it was and so that change, that 4-5 full growth, I think is a sign of how its acceptance has really increased in countries that are able to invest on fractional flow reserve (FFR) as a tool for doctors to make decisions with.
Use of Fractional Flow Reserve (FFR), Clinical evidence and international guidelines
The United States has had a challenge with legal cases of patients coming to doctors and to courts and saying, ‘I had a stent but I didn’t need a stent’, and actually some court decision by judges, who have said that doctors should have use Fractional Flow Reserve (FFR) in order to make their decisions and I think that is a sign of the acceptance.
Use of FFR, Clinical evidence and international guidelines
It is not just a tool that we as physicians are using to make the correct decisions. It is also a way of validating both the patients and others who are looking at these procedures and said that ‘Yes! this was a procedure that was necessary.’ So, it’s interesting that it has actually entered legal court decisions as well.
Usage of Fractional Flow Reserve (FFR) – Predictability and Precision
So, there are a lot of tests that we do in medicine day-to-day. For example, you might check your blood pressure, you might go and have your blood sugar level measured. All of those tests that we do have a certain imprecision to them. If you took your blood pressure and then you took it again you don’t get the same number each time. And, one of the important things is to understand how much that number might vary a little bit over time. We then compare Fractional Flow Reserve (FFR) to other tests like Blood Pressure, Blood Sugar for diabetes. We see that FFR actually has the smallest variation compared to those other tests. So, if we say, “Hey! Blood Pressure is a reasonable thing for us to use to make decisions.” Blood Cholesterol levels, Blood Sugar levels, Fractional Flow Reserve (FFR) is slightly better than all of those in terms of its precision.
Technological Innovation: Better patient Outcome
It’s so interesting to see the history of where Fractional Flow Reserve (FFR) started as a great example of the interplay between ‘a company that’s making a tool’ and ‘the physicians and researchers developing the evidence for it’. Back when the first company made the Fractional Flow Reserve (FFR) wires in the early 1990s they actually didn’t know what was it going to be useful for. The small sensors was made by a company that was into engineering and wanted to make something that no one else was doing before, but they were not certain how it will be useful for the doctor. And, in one of those lucky things that happened in history, the doctors came along and said you know we really need a monitorised sensors, so that we can put down the heart arteries. So, that was the first start and then is this collaboration between physicians and industry. Without either one of those two sides, they wouldn’t have known what to do with the product. If the physicians wouldn’t have been able to take an idea they had and find the tools to make it a reality. And that’s the kind of dynamics that really has continued for 20-30 years with Fractional Flow Reserve (FFR).