FARGO: FFR No Help for CABG in Patients With Multivessel Disease

In patients with multivessel disease, fractional flow reserve (FFR) assessment before CABG surgery does not improve outcomes compared with angiography-guided surgery, according to results of the FARGO trial.

“FFR appears as a good refinement tool to improve PCI decisions; but considering this first set of randomized data in CABG patients, FFR may be of a lesser interest in patients oriented towards CABG surgery,” say Gilles Montalescot, MD, PhD, and Benoît Lattuca, MD (both of Pitié-Salpêtrière University Hospital, Paris), in an editorial accompanying the results published online November 26, 2018, in the Journal of the American College of Cardiology.

Jack Boyd, MD (Stanford University, CA), who commented on the study for TCTMD, added that while it won’t change clinical practice, it does add information for those looking for an answer about how to use FFR in CABG. “This is probably the best data we have available to this point,” he said.

FARGO comes at a time when there are more questions than ever about the role of FFR guidance in the treatment of multivessel disease. As Montalescot and Lattuca note, “FFR is often used in routine practice as a decision tool for the type of revascularization (CABG or PCI) in multivessel disease patients, a situation where we lack evidence.” Just a few months ago, the FUTURE trial found that in an all-comers population of multivessel disease patients, FFR was associated with a doubling of the risk of death within the first year, with no beneficial impact on other outcomes.

Results Not in Favor of FFR

Led by Anne Langhoff Thuesen, MD (Odense University Hospital, Denmark), the FARGO trial enrolled 100 patients referred for CABG at three hospitals in Denmark. Patients were randomly assigned to FFR-guided or angiography-guided CABG. All had two- or three-vessel disease, with the majority in each group having a diagnosis of stable angina. A heart team constructed a graft plan based on the coronary angiogram. In the FFR-guided group, lesions with FFR > 0.80 were deferred, and a new graft plan was created.

Graft failure, the primary endpoint, was defined as less than TIMI flow grade 3 and/or anastomosis stenosis > 50%. At 6 months, the primary endpoint had occurred in a similar percentage of patients in the FFR and angiography groups (16% vs 12%; P = 0.97). This included graft failures to both FFR-positive and FFR-negative lesions in the angiography-guided group and graft failures to only FFR-positive lesions in the FFR-guided group.

Rates of death, MI, and stroke also were similar between the FFR and angiography groups, with no difference seen in the rate of revascularization before angiographic follow-up. After 6 months, deferred lesions showed a significant reduction in mean FFR from index to follow-up (0.89 ± 0.05 vs 0.81 ± 0.11; P = 0.002), a finding that Boyd said is “the most notable aspect of this paper,” because it contradicts a number of prior studies. It suggests that unlike in PCI, FFR “doesn’t have direct applicability to bypass surgery,” he added.

Extrapolation From PCI to CABG Not Relevant

Thuesen and colleagues say accelerating atherosclerosis of the deferred coronary lesion is one explanation for the unexpected finding “and might suggest that functionally guided surgical revascularization could be associated with more repeat revascularization at longer-term follow-up.” The findings are in contrast to results from DEFER and FAME, both of which supported the safety of deferral of functionally insignificant lesions in PCI-treated patients.

Montalescot and Lattuca note that the results should be interpreted cautiously and serve as an argument against using an FFR-guided approach when constructing a graft plan. They add that “the lessons learned from the FFR trials in PCI may not be extrapolated to CABG patients.”

To TCTMD, Boyd said while more research in this area is needed, it is also important for researchers doing this work to provide detailed information on how they devise their graft plans. “I would like to see more specifics on how that works in their program,” he said of the FARGO researchers. Approximately 12% of procedures in the study were not in compliance with the stated graft plan, mostly due to the small caliber of the coronary arteries or lack of grafting material, which Thuesen and colleagues acknowledge may have “complicated a study of different grafting strategies, although it reflected reality in surgical revascularization.”

Photo Credit: Engstrøm T. FFR Artifacts, Failures, and Troubleshooting. Presented at TCT 2018. September 24, 2018. San Diego, CA.