Fractional Flow Reserve and Intravascular Ultrasound-Guided Intervention Strategy for Clinical Outcomes in Patients With Intermediate Stenosis - FLAVOUR

Contribution To Literature:

Highlighted text has been updated as of August 27, 2023.

The FLAVOUR trial showed that FFR-guided PCI is noninferior to IVUS-guided PCI among patients with an intermediate coronary stenosis.


The goal of the trial was to evaluate fractional flow reserve (FFR) compared with intravascular ultrasound (IVUS) among patients with an intermediate coronary stenosis.

Study Design

  • Randomized
  • Parallel
  • Open-label

Patients with an intermediate coronary stenosis were randomized to FFR (n = 838) vs. IVUS (n = 844).

In the FFR group, percutaneous coronary intervention (PCI) was indicated if FFR ≤0.8 and considered optimized if post-PCI FFR ≥0.88.

In the IVUS group, PCI was indicated if minimal luminal area (MLA) ≤3 mm2, or >3 to 4 mm2 with plaque burden >70% and considered optimized if post-PCI MLA ≥5.5 mm2 and plaque burden at stent edge ≤55%.

  • Total number of enrollees: 1,682
  • Duration of follow-up: 24 months
  • Mean patient age: 65 years
  • Percentage female: 29%
  • Percentage with diabetes: 33%

Inclusion criteria:

  • ≥19 years of age
  • Stable coronary artery disease with an intermediate stenosis (40-70%) on coronary angiogram
  • Lesion eligible for PCI

Exclusion criteria:

  • Hypersensitivity or contraindication to any study medication
  • Active bleeding problem or coagulopathy
  • Target lesion in bypass graft or left main artery
  • Life expectancy <2 years

Other salient features/characteristics:

  • In the FFR group, the mean FFR was 0.83 and 50% had optimized PCI.
  • In the IVUS group, the mean MLA was 3.4 mm2 and 55% had optimized PCI.

Principal Findings:

The primary outcome, all-cause death, myocardial infarction (MI), or revascularization at 24 months, occurred in 8.1% of the FFR group vs. 8.5% of the IVUS group (p for noninferiority = 0.015). This finding was the same among tested subgroups.

Secondary outcomes:

  • MI at 24 months: 1.9% of the FFR group vs. 1.7% of the IVUS group (p = 0.70)
  • Revascularization at 24 months: 5.7% of the FFR group vs. 5.3% of the IVUS group (p = 0.71)
  • No difference in patient-reported outcomes (Seattle Angina Questionnaire) between treatment groups

Sex differences: 29.7% women. Women were older with higher ejection fraction but less likely to be smokers or have undergone prior PCI. Pre-PCI FFR among women was higher on average than in men, and MLA was lower. Women were less likely to undergo PCI compared with men (40.8% vs. 47.9%, p = 0.008), particularly in the FFR arm (25% vs. 36.8%, p = 0.001). The primary endpoint, target vessel failure (TVF), was lower among women than men (2.4% vs. 4.5%, p = 0.04), driven primarily by a lower rate of TV-MI or cardiac death (0.4% vs. 1.8%, p = 0.039). TVF was lower among women than men among those whose PCI was deferred (1.7% vs. 5.2%, p = 0.017) but not among those undergoing PCI (3.4% vs. 3.7%, p = 0.79). No difference was noted for both men or women with FFR or IVUS-guidance.


Among patients with an intermediate coronary stenosis, FFR-guided PCI was noninferior to IVUS-guided PCI. FFR-guided PCI was associated with a similar incidence of adverse cardiovascular events at 24 months compared with IVUS-guided PCI. Patient-reported outcomes were similar between the treatment groups. These results apply to patients with non–left main native coronary artery stenoses. Based on clinical outcome data from this trial, either coronary physiology or coronary anatomy can be used to guide coronary revascularization and either modality can be used to optimize stent implantation.

Women underwent PCI less frequently than men, which was attributable mostly to the FFR-guidance arm. Women whose PCI was deferred had better outcomes than men. Among those undergoing PCI, both strategies yielded similar results. These data suggest that a FFR-guided strategy may be preferable among women.


Zhang J, Jiang J, Hu X, et al. Sex Differences in Fractional Flow Reserve- or Intravascular Ultrasound-Guided Percutaneous Coronary Intervention. JACC Cardiovasc Interv 2023;Aug 27:[Epub ahead of print].

Presented by Dr. Xinyang Hu at the European Society of Cardiology Congress, Amsterdam, Netherlands, August 27, 2023.

Presented by Dr. Bon-Kwon Koo at the American College of Cardiology Annual Scientific Session (ACC 2022), Washington, DC, April 4, 2022.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Atherosclerotic Disease (CAD/PAD), Aortic Surgery, Cardiac Surgery and SIHD, Interventions and Coronary Artery Disease, Interventions and Imaging, Angiography, Echocardiography/Ultrasound, Nuclear Imaging

Keywords: ACC22, ACC Annual Scientific Session, Angina Pectoris, Constriction, Pathologic, Coronary Angiography, Coronary Artery Disease, Coronary Stenosis, ESC Congress, ESC23, Fractional Flow Reserve, Myocardial, Myocardial Infarction, Myocardial Ischemia, Myocardial Revascularization, Percutaneous Coronary Intervention, Stents, Ultrasonography, Interventional

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