Long-term prognostic implications of CT angiography-derived fractional flow reserve: Results from the DISCOVER-FLOW study

Background & Objectives The long-term prognostic implications of CT angiography-derived fractional flow reserve (FFRCT) remains unclear. We aimed to explore the long-term outcomes of FFRCT in the first-in-human study of it. Materials & methods A total of 156 vessels from 102 patients with stable coronary artery disease, who underwent coronary CT angiography (CCTA) and invasive FFR measurement, were followed. The primary endpoint was target vessel failure (TVF), including cardiovascular death, target vessel myocardial infarction, and target vessel revascularization. Outcome analysis with FFRCT was performed on a per-vessel basis using a marginal Cox proportional hazard model. Results During median 9.9 years of follow-up, TVF occurred in 20 (12.8%) vessels. FFRCT <= 0.80 discriminated TVF (hazard ratio [HR] 2.61, 95% confidence interval [CI] 1.06, 6.45). Among 94 vessels with deferral of percutaneous coronary intervention (PCI), TVF risk was inversely correlated with FFRCT (HR 0.62 per 0.1 increase, 95% CI 0.44, 0.86), with the cumulative incidence of TVF being 2.6%, 15.2%, and 28.6% for vessels with FFRCT >0.90, 0.81-0.90, and <= 0.80, respectively (p-for-trend 0.005). Predictive value for clinical outcomes of FFRCT was similar to that of invasive FFR (c-index 0.79 vs 0.71, P = 0.28). The estimated TVF risk was higher in the deferral of PCI group than the PCI group for vessels with FFRCT <= 0.81. Conclusion FFRCT showed improved long-term risk stratification and displayed a risk continuum similar to invasive FFR.