FFR is non-inferior to IVUS in improving PCI outcomes, FLAVOUR study.

In the contemporary cardiology practice, the use of both FFR and IVUS is considered to be the best strategy to improve clinical outcomes of PCI procedure. However, many cardiac catheterization laboratories have either FFR or IVUS but not both, and therefore a frequently asked question is "whether one device can be used both to make the decision to proceed with PCI and to improve stent implantation?"

This issue was recently addressed by authors Koo et al through the findings of the randomized FLAVOUR trial, published this week in NEJM. The trial has shown that in patients with intermediate stenosis undergoing PCI, FFR guidance was noninferior to IVUS guidance with respect to the composite primary outcome of death, myocardial infarction, or revascularization at 24 months.

FFR provides physiological assessment of lesion severity while IVUS can provide detailed anatomical information regarding the lumen, vessel, and plaque. However can they be used interchangeably remains a topic of debate.

For the present study, authors recruited 1682 patients with an intermediate coronary stenosis and randomly assigned them to either FFR guidance or IVUS guidance to make the decision whether to proceed with PCI and, if so, to improve the stenting procedure.

Revascularization was performed if the FFR was 0.80 or less or if IVUS identified a minimal luminal area of 3 mm2 or less or a luminal area of 3 to 4 mm2 with a plaque burden of more than 70%.

On the basis of these criteria, stents were implanted in 44.4% of the patients in the FFR group and in 65.3% of those in the IVUS group.

At 24 months, the composite outcome of death from any cause, myocardial infarction, or revascularization occurred in 8.1% of the patients in the FFR group and in 8.5% of those in the IVUS group, an absolute difference of 0.4 percentage points, which met the criteria for the noninferiority of FFR guidance.

"In this head-to-head comparison between FFR guidance and IVUS guidance for evaluating the need for PCI, investigators reexamined whether IVUS is useful in deciding whether an intermediate stenosis should be revascularized. They also reassessed the suitability of FFR in determining whether a stent has been successfully implanted. Since there were no apparent differences in the frequency of revascularization (driven either by ischemia or target lesion) during the follow-up period, these questions appear to be answered affirmatively and suggest that it is feasible to use only one of these tools to guide PCI", noted Jane A. Leopold, M.D. in an accompanying editorial.

The noninferiority of FFR guidance occurred with a lower incidence of target-vessel PCI in the FFR group than in the IVUS group, which led to the implantation of fewer stents and less frequent administration of dual antiplatelet agents.

Source: NEJM:

1. DOI: 10.1056/NEJMoa2201546

2. DOI: 10.1056/NEJMe2209148