FFR in Spotlight at C3: Controversy on Gray Zone

Interventional Academy Speaks to William Fearon, MD and Bernard DeBruyne, MD

With keen interest, I read the study by Kang et al regarding PCI in patients with gray zone FFR. I was even more intrigued when I read Dr. Hitinder Gurm’s summary perspective on the study published in ACC.org. I was surprised by his strong endorsement for deferred revascularization for patients with FFR in gray zone i.e. between 0.75 to 0.80. In interventional cardiology, even with blinded randomized data, we have a difficult time changing clinical practice patterns. In this case I doubt that I would have made such a strong endorsement for one strategy over other.  As a follow-up, I obtained the perspectives and expert opinions regarding the study by Drs. William Fearon and Bernard DeBruyne.  I asked each of them the critical question on whether a clinician should change their practice of treatment less than 0.80 FFR value based on FAME to 0.75?

In response,  Dr. William Fearon, Professor of Medicine at Stanford University Medical Center, commented, “Studies evaluating medical therapy in patients with gray zone FFR values have shown higher event rates with medical therapy when compared with patients treated medically with FFR values > 0.80. The question is at what FFR value does the benefit of PCI outweigh its risk? Based on the FAME 2 trial, one can conclude that this occurs in patients with FFR values ≤ 0.80. The study by Kang et al reminds us that there is likely less benefit with PCI in those patients with gray zone FFR values. However, because that study was not randomized, it is likely that the operators showed good clinical judgment and chose not to perform PCI on gray zone FFR patients with lower risk features and elected to perform PCI on the higher risk gray zone FFR patients. Comparing outcomes in this nonrandomized study is tricky because the differences in these patients may not have been accounted for in the analysis. For the time being, I recommend that operators continue to use their clinical judgment in patients who have gray zone FFR values. If the patient has a focal lesion in a large epicardial vessel and typical symptoms, then likely PCI will improve outcomes.  However, if the patient has atypical symptoms or is asymptomatic, or has more diffuse disease or a technically unattractive lesion, then medical therapy may be more appropriate.”

Similarly, Dr. Beranrd De Bruyne, Co-Director of the Cardiovascular Center Aalst in Belgium, had a similar reaction stating, “NO. This data should not change our recommendation. Moreover, a study by Adjedj et al Circulation 2017 also studied this question and found that patients in the gray zone benefit from revascularization. OF COURSE, common sense is needed and there is a trade-off: a patient with a long calcified lesion with two bifurcation and an FFR of 0.75 is a different animal than a short smooth type A lesion with 0.80.”

In summary, a clinician’s judgement for individual patient and lesion is of paramount importance. Let us not make our clinicians robots who is simply following algorithms and numbers.  We need to keep room for clinical judgement and best patient outcomes.

At C3, we will be debating this controversy along with many similar issues.  This is a MUST-ATTEND event for 2018!

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