Coronary Artery DiseaseComparison of Ticagrelor Versus Thienopyridine Loading Effect on Fractional Flow Reserve in Patients With Coronary Artery Disease

Ticagrelor loading dose (LD) increases adenosine plasma levels, which might interfere with fractional flow reserve (FFR) assessment because the latter is based on adenosine-induced hyperemia. In a prospective study, consecutive patients who underwent coronary angiography with at least 1 de novo stenosis >50% and <90% in severity amenable to intervention underwent FFR assessment using intravenous adenosine 140 μg/kg/min for 3 minutes. Patients were subsequently randomized to either ticagrelor 180 mg (n = 38) or control thienopyridine (n = 38) (prasugrel 60 mg [n = 28] or clopidogrel 600 mg [n = 10]), followed by a second FFR assessment of the target lesion 2 hours after drug. Pre-drug, steady hyperemia FFR (sFFR, median, first to third quartiles) was 0.82 (0.75 to 0.88) and 0.81 (0.75 to 0.88), p = 0.9, whereas post-drug, 0.82 (0.72 to 0.87) and 0.79 (0.73 to 0.86), p = 0.5, in thienopyridine and ticagrelor-treated patients, respectively. The primary end point of percent relative change in sFFR between pre- and post-drug periods was greater in ticagrelor- than thienopyridine-treated patients, −1.24 (−5.54 to 0.0) versus −0.51 (−3.68 to 3.21), p = 0.03, respectively. Absolute change in sFFR between pre- and post-drug periods was marginally higher in ticagrelor- than thienopyridine-treated patients −0.01 (−0.04 to 0.0) versus −0.005 (−0.03 to 0.02), p = 0.048, respectively. Reclassification of treatment decision at the sFFR ≤0.80 cutoff post-drug occurred in 6 (15.8%) versus 5 (13.2%) of ticagrelor- and thienopyridine-treated patients, respectively. In conclusion, after ticagrelor LD, an absolute and relative reduction in sFFR compared with thienopyridine LD is observed. Administration of ticagrelor should be considered as a potential source, albeit minor, of FFR variability.