FFR demonstrated continuous association with outcomes

Measuring fractional flow reserve was associated with fewer events and freedom from angina in a recent meta-analysis.

For the analysis, researchers examined 9,173 study-level lesions and 6,961 patient-level lesions, and hypothesized that lower FFR values would result in a higher risk and should, consequently, be associated with greater benefit from revascularization.

The median follow-up duration was 16 months for study-level data and 14 months for patient-level data.

Results indicated an increase in clinical events with decreases in FFR. Greater benefits of revascularization were reported in association with lower FFR values.

The threshold for outcomes-derived FFR occurred in the range between 0.75 and 0.80 in most cases, according to the researchers. However, they noted that this finding was limited by confounding related to indication.

An inverse relationship was reported for FFR measured immediately after stenting and prognosis (HR=0.86; 95% CI, 0.80-0.93). When FFR was used as a component to the intervention strategy, revascularization occurred approximately 50% less frequently as the rate reported for an anatomy-based strategy, but with 20% less adverse events and a 10% improvement in relief from angina.

“FFR demonstrates a continuous and independent relationship with subsequent outcomes, modulated by medical therapy vs. revascularization,” the researchers concluded. “Measurement of FFR immediately after stenting also shows an inverse gradient of risk, likely from residual diffuse disease. An FFR-guided revascularization strategy significantly reduces events and increases freedom from angina with fewer procedures than an anatomy-based strategy.”

John McB. Hodgson, MD, of the Case Western Reserve School of Medicine and MetroHealth Medical Center in Cleveland, wrote an editorial that described the study as an “elegant analysis” of FFR data from the last 2 decades.

“Using meta-analysis techniques, they have shown a continuous relationship between measured FFR and patient outcome,” he wrote. “Although the statistics may be a bit daunting for the average clinician (myself included), the message is quite clear: When FFR values are low, patients benefit from revascularization and when FFR values are high, we can do harm by proceeding with revascularization.”

Hodgson added that the results were consistent in left main lesions, patients with diabetes and those with ACS.

“For more than 10 years, as data have been published, the importance of routinely performing FFR has been emphasized in review articles and editorials,” Hodgson wrote. “FFR guidance has been shown to be of value in intermediate lesions, side branches, left main lesions, potential bypass graft insertion sites and in-stent restenosis lesions to name a few unique applications. An FFR-based interventional strategy has been shown to improve patient outcomes in balloon angioplasty, in bare-metal stent PCI, in drug-eluting stent PCI and in guiding surgical revascularization.”

Hodgson noted that the procedure is user-friendly and that guidelines include FFR for a cross section of intermediate lesions.

“So, one is left wondering what part of the FFR link don’t interventional cardiologists understand?” he wrote. “The data are clear; the cardiology community should not tolerate continuing to ignore it.”

For more information:

Johnson NP. J Am Coll Cardiol. 2014;64:1641-1654.

Hodgson JM. J Am Coll Cardiol. 2014;64:1655-1657.

Disclosure: The researchers report financial disclosures with several device companies, including Abbott Vascular, Boston Scientific, Medtronic, St. Jude Medical and Terumo. See the study for the full list of disclosures. Hodgson reports financial disclosures with Boston Scientific, Infraredx, St. Jude Medical and Volcano.