Fraction flow reserve

ffr

1. FRACTIONAL FLOW RESERVE Dr. Priyanka Thakur DM cardiology Resident

2. Coronary angiography is the most accurate morphologic assessment of the lumen of the epicardial coronary arteries till date, but is limited in gauging the functional repercussions of coronary stenoses .

3. LIMITATIONS OF CORONARY ANGIOGRAPHY highly subjective provides a 2–dimentional view of a 3-dimensional lumen. Severity of a stenotic lesion is reported in comparison to a normal reference segment . lumenography & does not provide information regarding vessel wall. An ecentric stenosis has varying appearance of severity in different views.

4. FFR (Fractional flow reserve)

5. T echnique to evaluate the hemodynamic relevance of coronary artery stenoses .  "the ratio of maximal flow achievable in the stenotic coronary artery to the maximal flow achievable in the same coronary artery if it was normal"

6. Normal value is 1 irrespective of the patient , artery or vascular bed Takes into account collateral blood flow Stenosis specific FFR value ≤ 0.80 is considered significant stenosis Independent of prevailing Systemic haemodynamics like heart rate , blood pressure & LV contractility reproducible since the microvasculature has the capacity to vasodilate till the same extent repeatedly

7. Relation between FFR & viable myocardium– If a stenotic vessel supplies a larger viable myocardial mass, there will be larger hyperaemic flow during maximal vasodilation resulting in a greater gradient between Pd & Pa & thus , a lower value of FFR. Therefore , the haemodynamic significance of a lesion is dependent on its perfusion territory.

8. Technique

9. Clinical Applications Intermediate lesions (50 to 80 %) Multivessel Coronary Artery Disease Left-Main Coronary Artery Disease Tandem and bifurcation Lesions CABG conduit patency

10. CLINICAL EVIDENCE

11. DEFER- Deferral Versus Performance of PCI of Non-Ischemia-Producing Stenoses Study Name Size Clinical Presentation FFR Cutoff Outcomes DEFER (2001) 325 patients at 14 medical centers Stable chest pain and an intermediate stenosis without objective evidence of ischemia 0.75 No benefit stenting a non-ischemic stenosis

12. FAME TRIAL - Fractional Flow Reserve Versus Angiography for Multivessel Evaluation  Study Size Trial Design Clinical Presentation FFR Cutoff Outcomes FAME study ( 2009) 1,005 patients at 20 medical centers Prospective, randomized Multivessel CAD 0.80 Routine measurement of FFR in patients with multivessel CAD who are undergoing PCI with drug-eluting stent significantly reduces MACE at 1 year

13. FAME 2 TRIAL

14. Muller et al. demonstrated good prognostication by deferring revascularization with a negative FFR for the long-term clinical outcome of patients with an angiographically intermediate left anterior descending coronary artery (LAD). In this study, medical treatment of patients with a hemodynamically nonsignificant stenosis (FFR ≥0.80) in the proximal LAD was associated with an excellent long-term clinical outcome, with survival at 5 years, which is similar to a control group without known CAD 

15. FFR in Acute Coronary Syndrome (ACS)

16. Study name Size Clinical Presentation FFR Cutoff Outcomes Compare Acute 2017 885 at 24 centers in Europe and Asia Patients with STEMI and multivessel disease who had undergone primary PCI of an infarct-related coronary artery 0.80 FFR-guided complete revascularization of non-infarct-related arteries in the acute setting resulted in lower MACE, driven by decreased revascularization

17. Indications and Guidelines for FFR ACC/AATS/AHA/ASE/ASNC/SCAI/SCCT/STS 2016 Appropriate Use Criteria for Coronary Revascularization in Patients With Acute Coronary Syndromes:  In the presence of an asymptomatic intermediate-severity non-culprit artery stenosis , revascularization was rated as “appropriate therapy,” provided that the FFR was ≤0.80.

18. European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS) 2014 FFR to identify hemodynamically relevant lesions in stable patients when evidence of ischemia is not available FFR guided PCI in patients with multivessel disease

19. ACC/AATS/AHA/ASE/ASNC/SCAI/SCCT/STS 2017 Appropriate Use Criteria for Coronary Revascularization in Patients With Stable Ischemic Heart Disease: Invasive measurements (such as FFR) may be very helpful in further defining the need for revascularization and may substitute for stress test findings . FFR ≤0.80 is abnormal and is consistent with downstream inducible ischemia .