JIM 2020: What Interventional cardiologists need to know about FFR-CT — Dr Gian Luca Pontone

Dr Gian Luca Pontone (Cardiology Center Monzino IRCCS, Milan, IT) unpacks fractional flow reserve-computed tomography (FFR CT) for interventional cardiologists.
 
Questions:
1. How is FFR-CT changing clinical practice?
2. Is FFR-CT a viable alternative to more invasive procedures?
3. In which clinical scenarios is FFR-CT most beneficial? 
4. What are the benefits of FFR-CT?
5. What are the limitations of FFR-CT?
6. What key details should interventional cardiologists know about FFR-CT?
 
Filmed on location at the JIM 2020.
Interviewer: Ashlynne Merrifield
Videographer: Dom Woodruff
 

Transcript Below :

Question 1 : How is FFR-CT changing clinical practice?

[Pontone] The FFR-CT is a wonderful tool to improve the performance of a CTA, CT Angiography, in patients with suspected coronary artery disease. Everybody knows that according to the new guidelines, CDC guidelines, now the CTA is a test that we can use as a first level to rule out the presence of coronary artery disease. But the main limitation of CT angiography is the limited positive predictive value in case we found obstructive coronary artery disease. The addition of FFR-CT changed the paradigm, changed the practice because it's able to improve the positive predictive value of a CT angiography. In this way it's able to limit the number of false positive case [Sic]. So, the most important impact in clinical practice is to limit the unnecessary invasive coronary angiography in case of a positive CT angiography. 

Question 2 : Is FFR-CT a viable alternative to more invasive procedures?

[Pontone]  The main aim of FFR-CT is to avoid invasive procedures that are not necessary. But at the same time it's a very robust gatekeeper to improve the people with significant disease to be referred to the cath lab. So, in general, the expectation is to reduce the number of diagnostic evaluations and to improve the rate of revascularization, appropriate revascularization, in the cath lab. This is the main aim of FFR-CT in clinical practice. 

Question 3 : In which clinical scenarios is FFR-CT most beneficial?

[Pontone] The FFR-CT is typically very useful when you have an intermediate stenosis in cardiac CT. I mean, intermediate stenosis ranging between 50% to 70% of a luminal narrowing. Because in this specific setting, we have to kind of a problem [Sic]. First, a potential risk of overestimation of coronary artery stenosis by CTA. Second, incase there is two obstructive coronary artery disease intermediate lesions the question that we have in mind: is there is ischaemia associated or not? FFR-CT is extremely useful in this setting because it is a wonderful tool to resolve both limitations. First, to limit the overestimation. Second, in case of correct estimation to detect the presence of ischaemia. In this way, we have a more efficient result from non-invasive evaluation. 

Question 4 : What are the benefits of FFR-CT?

[Pontone] The main benefit in terms of cost effectiveness as demonstrated by the PLATFORM trial, is to reduce the cost for management of a patient with suspected coronary artery disease. Indeed, when we have a diagnostic workup, in which FFR-CT is used as a gatekeeper to a cath lab, the overall cost is lower than about 50% as compared to the standard diagnostic workup. This means that we can save a lot of money and at the same time, to reduce the number of patients to be referred to the cath lab. And just to be more efficient, to identify the patient that they really receive benefit from the invasive evaluation. 

Question 5 : What are the limitations of FFR-CT?

[Pontone] The main limitation of FFR-CT is still the limited positive predictive value, especially in the subset of a patient with a calcified lesion. Indeed, as you know, when there are calcification in coronary arteries, the performance of FFR-CT could be limited. Of course, in this case, it is very important to check which FFR-CT value we have. I mean that if the value is very low, there is a good chance it is a true, significant disease. But the problem is that when we have a value in the gray zone between 0.7 to 0.8 in presence of calcified lesion. In this specific setting, we need probably more information to add on top of FFR-CT to be more precise. And one option is to stress CT perfusion. 

Question 6 : What key details should interventional cardiologists know about FFR-CT?

[Pontone]I believe that in the next future, the background of cardiac CT in general, more specific FFR-CT should be part of the general background of interventional cardiology. This is very important because in the next scenario, the most common pathway that we will have is that the interventional cardiologist will treat patient in which everything was already studied in a non-invasive setting. And so, to this regard, it's very important that an interventional cardiologist has a general background about these new techniques. They are able to manipulate the images sent to have a personal interpretation about the data. Because this, I believe, makes more efficient also the strategy of revascularization in the cath lab.