Sex Differences in FFR- and IVUS-Guided PCI

Quick Takes

  • In intermediate stenosis, the use of FFR led to a lower PCI rate but had a similar prognostic value compared to IVUS in both women and men.
  • Despite the same % of diameter stenosis, women had a smaller minimal lumen area, smaller plaque burden, and higher FFR.
  • Overall, women had a lower rate of PCI than men and showed a lower target vessel failure rate. According to the treatment type (PCI vs. deferral), the cumulative incidence of target vessel failure was lower in women than in men among those with the deferral of PCI.

Study Questions:

Sex differences in treatment and clinical outcomes according to physiology- or imaging-guided percutaneous coronary intervention (PCI) strategies remain unclear. Are there any sex differences in procedural characteristics and clinical outcomes in fractional flow reserve (FFR)- versus intracoronary ultrasound (IVUS)-guided PCI?


The FLAVOUR (Fractional Flow Reserve and Intravascular Ultrasound for Clinical Outcomes in Patients With Intermediate Stenosis) trial was an investigator initiated, prospective, multinational, randomized controlled trial that compared FFR- and IVUS-guided PCI strategies. This is a secondary analysis of this randomized trial aimed to investigate the impact of sex on procedural characteristics, treatment, and clinical outcomes according to different strategies and treatment types (PCI vs. deferral of PCI, also referred to as deferral group). The criterion of FFR-guided revascularization was an FFR ≤0.80. The criteria of IVUS-guided PCI were minimal lumen area (MLA) ≤3 mm2; or 3 mm2 < MLA ≤4 mm2 and plaque burden >70%. The primary outcome was target vessel failure (TVF) at 24 months, defined as a composite of cardiac death, target vessel myocardial infarction, and target vessel revascularization. The Seattle Angina Questionnaire (SAQ) was used to quantify patient-reported outcomes regarding the symptoms and daily life.


Of 1,619 patients, 30% were women. Women showed a smaller MLA (3.3 ± 1.2 mm2 vs. 3.5 ± 1.3 mm2, p = 0.022), a smaller plaque burden (68.2 ± 10.3% vs. 70.9 ± 10.0%, p = 0.001), and a less severe area stenosis (69.0 ± 8.6% vs. 72.0 ± 9.0%, p < 0.001). Compared with men, women had a smaller MLA, smaller plaque burden, and higher FFR. They had a lower PCI rate (40.8% vs. 47.9%, p = 0.008), which was mainly contributed by FFR guidance. Overall, women showed a lower TVF rate (2.4% vs. 4.5%). According to the treatment type, the cumulative incidence of TVF was lower in women than in men among those with the deferral of PCI (1.7% vs. 5.2%). Moreover, in multivariate regression analyses, sex was an independent predictor of TVF in overall patients (adjusted hazard ratio [HR], 1.96; 95% confidence interval [CI], 1.04-3.73; p = 0.039) and in the Deferral group (adjusted HR, 3.70; 95% CI, 1.44-9.50; p = 0.007). However, this trend was not observed in patients who underwent PCI. In both women and men, there were no differences in clinical outcomes between the FFR- and IVUS-guided strategies.


This study explored the impact of sex on physiology and outcomes in revascularization. The main findings were as follows: 1) Despite visually comparable % of diameter stenosis between sexes, an in-depth evaluation by FFR or IVUS showed less severe disease burden in women than that in men. 2) Women had a lower rate of PCI than men, which was attributed to the difference in patients guided by FFR. 3) Women experienced better clinical outcomes at 24 months than men, and such a favorable prognosis in women was mainly driven by the lower event rate in the Deferral group. 4) There were no differences in clinical outcomes between the FFR- and IVUS-guided strategies in both women and men.


The lack of sex-specific guidelines in the management of coronary artery disease (CAD) in women in terms of PCI and TVF has been challenging, especially since there is a unique phenotype of CAD in women, such as more nonobstructive plaques, higher resting flow, and less calcified lesions. In the current study, although visually estimated % of diameter stenosis was similar between the two sexes, an advanced evaluation by FFR or IVUS indicated that women had less severe disease burden than men. This study shows that despite similar diameter in both sexes, women had less severe MLA and IVUS was smaller in women, highlighting that angiogram might be overestimating the lesion. Incorporation of advanced imaging before PCI to assess lesion severity might provide better adjudication of treatment strategies (i.e., PCI vs. deferral), and lead to reducing the number of PCIs in intermediate stenosis. Sex-specific attention to lesion type and severity is needed for appropriate selection of patients.

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

Keywords: Coronary Artery Disease, Coronary Stenosis, ESC Congress, ESC23, Fractional Flow Reserve, Myocardial, Myocardial Infarction, Myocardial Ischemia, Myocardial Revascularization, Percutaneous Coronary Intervention, Plaque, Atherosclerotic, Sex Characteristics, Ultrasonography, Interventional

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