Addition of Computed Tomography-derived Fractional Flow Reserve in the diagnostic pathway of patients with stable coronary artery disease: the FUSION randomized controlled trial.
BACKGROUND Computed Tomography-derived Fractional Flow Reserve (FFRct) integrates anatomical and functional information, which is particularly useful for stable coronary artery disease (CAD) patients with at least intermediate stenosis. OBJECTIVES We investigated the impact of adding FFRct to the diagnostic pathway of CAD patients with a 50-90% stenosis on Coronary Computed Tomography Angiography (CCTA). METHODS FUSION is an investigator-initiated, multicenter, randomized controlled trial involving patients with 50-90% stenosis in ≥1 coronary artery on CCTA. Patients were randomized to FFRct-guided or usual care. The primary endpoint was invasive coronary angiography (ICA) without obstructive CAD at 90 days. Secondary endpoints included ICA without obstructive CAD, major adverse cardiac events (MACE), and costs at 1 year, as well as revascularizations, and quality of life at 90 days and 1 year. ICA use was assessed as a post-hoc exploratory endpoint. RESULTS Overall, 528 patients (median age 63 [57-69] years, 59% male) were randomized to FFRct-guided (n=263) or usual care (n=265). At 90 days, the rate of ICA without obstructive CAD was significantly lower in the FFRct group than in the usual care group (18% (48/263) versus 33% (87/265); odds ratio 0.46; 95% confidence interval, 0.31-0.69; P<0.001). ICA rate was 39% (102/263) versus 51% (136/265), respectively (P=0.004). Both differences persisted at 1 year. Revascularization rates were similar: 20% (52/263) versus 20% (53/265) at 1 year, respectively (P=0.948). Quality of life, costs, and MACE did not differ between groups, although the clinical event rates were low. CONCLUSIONS Adding FFRct to the diagnostic pathway of patients with a 50-90% stenosis on CCTA reduced the rate of ICA without obstructive CAD at 90 days and 1 year, without differences in revascularizations, quality of life, and costs compared to usual care. Clinical event rates were similar, although low. The rate of overall ICA use, a post-hoc exploratory outcome, was also reduced at 90 days and 1 year.