RCT: QFR Not Non-Inferior to FFR in Guiding Revascularization of Intermediate Coronary Stenoses
10 Nov, 2024 | 13:23h | UTCBackground: Fractional flow reserve (FFR) is the gold standard for assessing the functional significance of intermediate coronary stenoses and guiding revascularization decisions. Quantitative flow ratio (QFR) is a novel, noninvasive computational method for estimating FFR from angiography without the need for pressure wires. Despite promising diagnostic accuracy, the efficacy of QFR compared to FFR in clinical outcomes remains uncertain.
Objective: To determine whether a QFR-guided strategy is non-inferior to an FFR-guided strategy regarding 12-month clinical outcomes in patients with intermediate coronary stenosis.
Methods: In this multicentre, randomized, open-label, non-inferiority trial (FAVOR III Europe), 2,000 patients from 34 European centers with intermediate coronary stenosis (40–90% diameter stenosis) were randomized 1:1 to QFR-guided or FFR-guided revascularization strategies. The primary endpoint was a composite of death, myocardial infarction, and unplanned revascularisation at 12 months.
Results: At 12 months, the primary endpoint occurred in 6.7% of patients in the QFR group and 4.2% in the FFR group (hazard ratio [HR] 1.63; 95% CI 1.11–2.41). The upper limit of the 90% CI exceeded the predefined non-inferiority margin, indicating that QFR did not meet non-inferiority to FFR. Additionally, more patients underwent revascularisation in the QFR group (67.5%) compared to the FFR group (59.9%).
Conclusions: A QFR-guided strategy did not demonstrate non-inferiority to an FFR-guided strategy for guiding coronary revascularization in patients with intermediate stenoses. The use of QFR led to more revascularizations without an improvement in clinical outcomes.
Implications for Practice: While QFR offers a non-invasive alternative to FFR, these findings suggest that QFR should not replace FFR when available for guiding revascularization decisions in intermediate coronary stenosis.
Study Strengths and Limitations: Strengths include a large sample size and a multicentre design enhancing generalisability. Limitations encompass the lack of blinding, potential operator learning curves with QFR, and a lower-than-expected event rate in the FFR group, which may have affected the non-inferiority assessment.
Future Research: Further studies are warranted to refine QFR technology and evaluate its role in different patient populations and clinical settings where FFR is not readily available.