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

Background--variations in distal coronary pressure (pd)/aortic pressure (pa) ratio during steady-state hyperemia with standard (140 μg/kg per minute) adenosine dose may hamper accurate fractional flow reserve assessment. this study investigated to what extent an increased adenosine dose can overcome pd/pa variation. 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 μg/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 δpd/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. conclusions-pd/pa variability is frequently observed during standard adenosine infusion and is significantly decreased following a high (200 μg/kg per minute) adenosine dose. this is achieved without a significant difference in the minimum pd/pa. © 2016 the authors.