BENEFIT AND PITFALLS OF FFR IN CORONARY INTERVENTION

1. FFR GUIDED CORONARY
INTERVENTION
DR. MAHENDRA
CARDIOLOGY,JIPMER

2. Challenges in daily practice
• Patients with recent myocardial infarction , questions pertain to
lesions not responsible for symptoms or infarct—so called “non
culprit” lesions .
• Subsequent cardiovascular events appear equally likely in non
culprit lesions following MI .
• Patients with stable angina, questions surround the choice
between medical therapy and revascularization
• Difficulty is identifying specific lesions that are functionally
significant or that will likely lead to adverse events.
• Frequent occurrence of multivessel disease poses additional
challenges.
• Noninvasive tests may lack sensitivity and specificity to detect
multivessel disease and treatment decisions can be complex .

5. Fractional flow reserve
• FFR is used to assess the physiologic consequences of
obstruction with a goal of predicting benefit from
revascularization or which lesions should be treated .
• Derived from the ratio of the mean distal coronary artery
pressure (Pd) to the mean aortic pressure (Pa) during the
period of maximum hyperemia.
• Fractional flow reserve is not affected by changes in the
hemodynamic conditions or microcirculation.
• ‘‘normal’’ ratio is expected to be 1.
• Values less than 0.75 to 0.80 are considered functionally
ischemic, while those 0.94 to 1.0 normal.

6. What Fractional Flow Reserve Value
Defines Ischemia?
 FFR value <0.75 was associated with reversible ischemia on
noninvasive stress testing (exercise stress test, nuclear scan,
and dobutamine stress echocardiogram) with 88%sensitivity,
100% specificity, 100% positive predictive value, 88% negative
predictive value, and 93% accuracy.
 DEFER study and other studies have used an FFR value of
<0.75 as the cutoff for ischemia.
 FFR value >0.80 has been shown to exclude an ischemia-
producing lesions, with predictive value of >95%.

7. • Coronary stenosis can be arbitrarily classified into 3 groups on
the basis of FFR values:
a. non–ischemic stenosis with FFR >0.80
b. ischemia-producing stenosis with FFR <0.75.
c. gray zone with FFR values between 0.75 and 0.80.

8. Applications for Fractional Flow Reserve in Coronary
Artery Disease
• Single-Vessel Disease-
• DEFER study has shown that patients with single vessel stenosis and FFR
>0.75 who did not undergo PCI had excellent outcomes.
• The risk of cardiac death or myocardial infarction (MI) related to the
stenosis was <1% per year and was not reduced with PCI.
• patients with single-vessel stenosis and FFR <0.75 are 5× more likely to
experience cardiac death or MI within 5 years, despite undergoing
revascularization.
• medical treatment of patients with proximal left anterior descending
stenosis and FFR >0.80had excellent5-year outcomes

9. • patients with small coronary arteries (diameter <2.8 mm), FFR can
safely determine stenosis that necessitate revascularization.
• In the Physiologic and Anatomical Evaluation Prior to and After
Stent Implantation in Small Coronary Vessels (PHANTOM) trial, 60
patients with small coronary arteries underwent FFR.
• group with FFR <0.75 underwent revascularization.
• At 1 year, there was no occurrence of MI or death in either group.
• patients with FFR <0.75, 24% underwent a repeat PCI, but only
2.6% of patients with FFR >0.75 underwent revascularization.

10. Left Main Stenosis
• Nonischemic FFR values (>0.80) in left main lesions are associated with
excellent long-term outcomes.
• accurate LM FFR reflects flow through both the LAD and the CFX.
• myocardial bed for the LM is the summed territories of both the LAD and
the CFX.
• LM bed can be even larger if the RCA is occluded and there is collateral
supply from the left coronary system.
• isolated LM narrowing with no LAD, CFX, or RCA stenosis reflects the
physiologic significance of just the LM narrowing.
• LM narrowing plus LAD stenosis could produce a higher LM FFR because
the LM bed is reduced in size.
• LM FFR alone cannot be accurately measured just as when there are serial
lesions.

11. • Tandem Lesions-
• Tandem lesions are defined as 2 separate lesions with >50%stenosis each
in the same coronary artery, separated by an angiographically normal
segment.
• If the FFR is<0.75 PCI for the stenosis that showed marked narrowing
first and then repeating the FFR measurement.
• If the FFR remains<0.75,the other stenosis was revascularized as well ,in
contrast, if the FFR value of the first lesion increased after PCI to >0.75,
then these second lesion was treated only medically.

14. Multi vessel Coronary Artery Disease

16. Exclusion criteria
• angiographically significant left main coronary artery
disease
• previous coronary artery bypass surgery
• cardiogenic shock
• extremely tortuous or calcified coronary arteries
• a life expectancy of 2 years
• pregnancy
• contraindication to DES placement.

23. • Discussion
• Multi vessel CAD, favorable of FFR during PCI as compared to PCI
guided by angiography alone is maintained at 2-year follow up.
• combined rate of death and myocardial infarction were significantly
lower among patients in the FFR-guided group.
• composite end point of death, need for revascularization was no
longer significantly lower in FFR-guided group.
• outcome in initially deferred lesions on the basis of FFR 0.80 was
excellent, underscoring the safety of the FFR guided approach.
• incidence of all types of adverse events was consistently reduced by
roughly 30%.
• The absolute risk for MACE was reduced by 4.5%.

24. Natural Course of Lesions Deferred on
PCI-Based FFR Measurements
• Randomized trial to address this concern is the DEFER (FFR to
Determine Appropriateness of Angioplasty in Moderate
Coronary Stenosis) study was done

27. • 5-year event-free survival rates similar in the deferred and
PCI groups .
• Composite rates of cardiac death and acute myocardial
infarction in the deferred, PCI, and reference groups were
3.3%, 7.9%, and 15.7%, respectively.
• Functionally nonsignificant coronary stenosis, regardless of
angiographic stenosis, could be safely deferred for up to 5
years.

28. IVUS VS FFR

30. • IVUS cannot directly estimate the functional significance of
coronary stenosis.
• Strong correlations have been observed between IVUS-
measured minimal lumen area (MLA) and inducible ischemia
as determined by myocardial SPECT imaging, coronary flow
reserve, and FFR.
• An IVUS MLA of 4 mm2 is theoretically large enough to affect
coronary blood flow.
• It is generally accepted that 50% diameter stenosis, which
corresponds to 75% area stenosis, is significant.

34. • FFR values of lesions with MLA 4 mm2 were widely scattered
• 66% of analyzed lesions had MLA 4 mm2 but FFR 0.80.
• Using our new, stricter criteria of MLA, 2.4 mm2, 30% of
analyzed lesions had MLA 2.4 mm2 but FFR 0.80.
• use of our new IVUS MLA criteria may avoid unnecessary
procedures in 36% of coronary lesions investigated.
• IVUS MLA criteria alone cannot predict the result of FFR
measurement.
• The FFR value and IVUS-measured parameters are
complementary and not competitive.

35. Other study
• FAME 2 Study
• conclusively address the question of whether performing PCI
in lesions with abnormal FFR results leads to better outcome
compared with deferring PCI, a subsequent clinical study,
FAME 2, was conducted.

38. FAMOUS-NSTEMI

40. Algorithm of functional angioplasty

41. THANK YOU