Effect of High (200 lg/kg per Minute) Adenosine Dose Infusion on Fractional Flow Reserve Variability

Methods and Results-—In a prospective, single-arm study, out of 95 prospectively screened patients, 38 (40.0%) exhibited significant (≥0.05 difference of max Pd/Pa minus min Pd/Pa) variations in Pd/Pa from 15 s post Pd/Pa dip and until the end of a 3-minute adenosine (140 lg/kg per minute) infusion. Thirty patients agreed to participate in a post 5-minute repeat fractional flow reserve assessment using 200 lg/kg per minute 3-minute adenosine infusion. The study’s co-primary end point of Pd/Pa coefficient of dispersion was lower for the high versus standard adenosine dose: 1.31 (1.13–2.72) versus 2.76 (2.38–5.60), P=0.002. The study’s co-primary end point of DPd/Pa was also lower for the high versus standard adenosine dose: 0.065 (0.038–0.10) versus 0.08 (0.06–0.11), P=0.002. This difference was mainly driven by the lowering effect of the high adenosine dose on the maximum Pd/Pa compared to the standard dose: 0.84 (0.81–0.93) versus 0.90 (0.83–0.95), P=0.007, while minimum Pd/Pa remained unaffected. High adenosine dose was adequately tolerated by all patients, without requiring infusion discontinuation in any case.