Clinical Use of Coronary CTA–Derived FFR for Decision-Making in Stable CAD

Abstract

ObjectivesThe goal of this study was to assess the real-world clinical utility of fractional flow reserve (FFR) derived from coronary computed tomography angiography (FFRCT) for decision-making in patients with stable coronary artery disease (CAD). BackgroundFFRCT has shown promising results in identifying lesion-specific ischemia. The real-world feasibility and influence on the diagnostic work-up of FFRCT testing in patients suspected of having CAD are unknown. MethodsWe reviewed the complete diagnostic work-up of nonemergent patients referred for coronary computed tomography angiography over a 12-month period at Aarhus University Hospital, Denmark, including all patients with new-onset chest pain with no known CAD and with intermediate-range coronary lesions (lumen reduction, 30% to 70%) referred for FFRCT. The study evaluated the consequences on downstream diagnostic testing, the agreement between FFRCT and invasively measured FFR or instantaneous wave-free ratio (iFR), and the short-term clinical outcome after FFRCT testing. ResultsAmong 1,248 patients referred for computed tomography angiography, 189 patients (mean age 59 years; 59% male) were referred for FFRCT, with a conclusive FFRCT result obtained in 185 (98%). FFRCT was ≤0.80 in 31% of patients and 10% of vessels. After FFRCT testing, invasive angiography was performed in 29%, with FFR measured in 19% and iFR in 1% of patients (with a tendency toward declining FFR-iFR guidance during the study period). FFRCT ≤0.80 correctly classified 73% (27 of 37) of patients and 70% (37 of 53) of vessels using FFR ≤0.80 or iFR ≤0.90 as the reference standard. In patients with FFRCT >0.80 being deferred from invasive coronary angiography, no adverse cardiac events occurred during a median follow-up period of 12 (range 6 to 18 months) months. ConclusionsFFRCT testing is feasible in real-world symptomatic patients with intermediate-range stenosis determined by coronary computed tomography angiography. Implementation of FFRCT for clinical decision-making may influence the downstream diagnostic workflow of patients. Patients with an FFRCT value >0.80 being deferred from invasive coronary angiography have a favorable short-term prognosis.