Quantitative flow ratio versus fractional flow reserve: 2-year follow-up of the FAVOR III Europe trial

BACKGROUND: Quantitative flow ratio (QFR) is an angiography-based method for estimating fractional flow reserve (FFR). The FAVOR III Europe trial showed that QFR guidance did not meet non-inferiority to FFR guidance, as measured by a composite endpoint of all-cause death, myocardial infarction, and unplanned revascularisation at 12 months. AIMS: We sought to report the 2-year outcomes of the QFR-guided diagnostic strategy and the FFR-guided strategy as applied in the FAVOR III Europe trial. METHODS: FAVOR III Europe was a multicentre, randomised, open-label, non-inferiority trial. A total of 2,000 patients from 34 European medical centres were randomised to undergo QFR- or FFR-guided revascularisation of intermediate coronary artery stenoses. Endpoints assessed at the 2-year follow-up included the rates of major adverse cardiac events (MACE) and its individual components of all-cause death, myocardial infarction, and unplanned revascularisation. The rates of MACE were compared for superiority by unadjusted Cox regression analysis. The outcomes from 1 to 2 years were explored in a landmark analysis. RESULTS: At 2 years, the rates of MACE were 9.7% in the QFR group and 7.4% in the FFR group (hazard ratio [HR] 1.34, 95% confidence interval [CI]: 0.98-1.81; p=0.064). In the landmark analysis, the rates of MACE between 1 and 2 years were 3.2% in the QFR group and 3.2% in the FFR group (HR 0.97, 95% CI: 0.58-1.62; p=0.92). CONCLUSIONS: The excess risks associated with QFR-guided revascularisation compared with FFR were confined to the first year. From 1 to 2 years, the rates of MACE developed similarly in the QFR and the FFR groups.