Discordance Between Angiographic Assessment and Fractional Flow Reserve or Intravascular Ultrasound in Intermediate Coronary Lesions: A Post-hoc Analysis of the FLAVOUR Trial.

Background and Objectives: Angiographic assessment of coronary stenosis severity using quantitative coronary angiography (QCA) is often inconsistent with that based on fractional flow reserve (FFR) or intravascular ultrasound (IVUS). We investigated the incidence of discrepancies between QCA and FFR or IVUS, and the outcomes of FFR- and IVUS-guided strategies in discordant coronary lesions.
Methods: This study was a post-hoc analysis of the FLAVOUR study. We used a QCA-derived diameter stenosis (DS) of 60% or greater, the highest tertile, to classify coronary lesions as concordant or discordant with FFR or IVUS criteria for percutaneous coronary intervention (PCI). The patient-oriented composite outcome (POCO) was defined as a composite of death, myocardial infarction, or revascularization at 24 months.
Results: The discordance rate between QCA and FFR or IVUS was 30.2% (n=551). The QCA-FFR discordance rate was numerically lower than the QCA-IVUS discordance rate (28.2% vs. 32.4%, p=0.050). In 200 patients with ≥60% DS, PCI was deferred according to negative FFR (n=141) and negative IVUS (n=59) (15.3% vs. 6.5%, p<0.001). The POCO incidence was comparable between the FFR- and IVUS-guided deferral strategies (5.9% vs. 3.4%, p=0.479). Conversely, 351 patients with DS <60% underwent PCI according to positive FFR (n=118) and positive IVUS (n=233) (12.8% vs. 25.9%, p<0.001). FFR- and IVUS-guided PCI did not differ in the incidence of POCO (9.5% vs. 6.5%, p=0.294).
Conclusions: The proportion of QCA-FFR or IVUS discordance was approximately one third for intermediate coronary lesions. FFR- or IVUS-guided strategies for these lesions were comparable with respect to POCO at 24 months.
Trial Registration: ClinicalTrials.gov Identifier: NCT02673424.
Competing Interests: Dr. Joo Myung Lee has received institutional research grants from Abbott Vascular, Boston Scientific, Philips Volcano, Terumo Corporation, Donga-ST, and Zoll Medical. Dr. Joo-Yong Hahn received an Institutional Research Grant from the National Evidence-based Healthcare Collaborating Agency, Ministry of Health & Welfare, Republic of Korea, Abbott Vascular, Biosensors, Boston Scientific, Daiichi Sankyo, Donga-ST, Hanmi Pharmaceutical, and Medtronic Inc. Dr. Bon-Kwon Koo received an institutional research grant from Abbott Vascular, Boston Scientific, and Phillips. The authors declare no competing interests.
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