Читать книгу Interventional Cardiology - Группа авторов - Страница 195

When both iFR and FFR are measured, a mismatch is possible in 1 in 5 cases of truly moderate disease. This is less likely in truly severe and truly mild stenoses. To date, there is no randomized data for this subset of patients, but close observational studies have suggested there is no difference in event rates when resting indices are negative and FFR is positive; the event rate is the same as seen when all the indices are negative [88]. A higher event rate has been demonstrated when all the indices are ischemic and the vessels are deferred [88].

In the setting of a mismatch, there are three basic clinical options: (i) treat according to the most positive index, (ii) treat according to the most negative index, (iii) use other data to act as an arbiter for clinical decision‐making.

In the case of option (i) future events will likely be driven by the quality of the stented segment; therefore, any treatment should be performed at the highest possible quality. Imaging should be used to support the intervention and ensure maximum lumen area is achieved. Post‐stenting physiology is advisable to ensure a genuine physiological gain is achieved; if there is no appreciable gain, then this suggests that the difference between the two parameters was not solely due to the lesion being assessed.

If option (ii) is chosen and the lesion is deferred, then escalated medical therapy and close observation would be appropriate. If there are ongoing symptoms or if quality of life is reduced, PCI still remains a viable option.

If (iii) is pursued, then other clinical parameters and patient symptoms should be considered for decision making. Occasionally, intravascular imaging may be helpful to evaluate for plaque instability, very large plaque burden or significantly decreased minimal lumen area.

In all cases, one should recall that the index is not an arbiter of clinical medicine and is used to supplement clinical decision making. The issue of mismatch dichotomy has resulted from the need of hard cut‐points during the index development. One should recall that there is no true hard point of “ischemia” – rather it is a continuum which should be treated as such.