Use of Fraction Flow Reserve to Predict Changes over Time in Management of Superficial Femoral Artery

Abstract

Peripheral arterial disease is a condition characterized by progressive arterial narrowing, which affects patients' quality of life. The purposes of this study were to (1) establish the feasibility of obtaining peripheral fractional flow reserve (pFFR) in the peripheral vascular circulation, (2) demonstrate an association between baseline pFFR and peak systolic velocity (PSV) measured by duplex ultrasound, and (3) correlate postintervention pFFR with future restenosis using the change in PSV over time as a surrogate. Twenty patients underwent baseline ankle brachial index (ABI) and PSV testing. Pre- and postintervention pFFR was performed. Patients were followed with three ABI and PSV recordings during the 1 year follow-up period. The association between baseline PSV, ABI, and pFFR with changes in PSV over time were explored. Predictors of postprocedural PSV over time were determined. The baseline translesional-resting ratio was significantly different from the pFFR using adenosine (0.79 ± 0.08 vs. 0.71 ± 0.09, P = 0.01). Baseline PSV was significantly associated with preintervention pFFR (-0.77, P < 0.001). Compared to patients with a postprocedure pFFR > 0.95, patients with a postprocedure pFFR < 0.95 had a significantly more rapid rise in PSV over time (P = 0.009). This is the first study to demonstrate that the peripheral vascular bed does respond to vasodilatation thereby supporting the use of pFFR for this procedure. In our study, postintervention pFFR < 0.95 predicted a more rapid increase in PSV over time, which is a reasonably accepted surrogate for restenosis.