title: Comparison of the intracoronary continuous infusion method using a microcatheter and the intravenous continuous adenosine infusion method for inducing maximal hyperemia for fractional flow reserve measurement.
abstract: BACKGROUND
  Inducing stable maximal coronary hyperemia is essential for measurement of fractional flow reserve (FFR). We evaluated the efficacy of the intracoronary (IC) continuous adenosine infusion method via a microcatheter for inducing maximal coronary hyperemia.
  
  
  METHODS
  In 43 patients with 44 intermediate coronary lesions, FFR was measured consecutively by IC bolus adenosine injection (48-80 microg in left coronary artery, 36-60 microg in the right coronary artery) and a standard intravenous (IV) adenosine infusion (140 microg x min(-1) x kg(-1)). After completion of the IV infusion method, the tip of an IC microcatheter (Progreat Microcatheter System, Terumo, Japan) was positioned at the coronary ostium, and FFR was measured with increasing IC continuous adenosine infusion rates from 60 to 360 microg/min via the microcatheter.
  
  
  RESULTS
  Fractional flow reserve decreased with increasing IC adenosine infusion rates, and no further decrease was observed after 300 microg/min. All patients were well tolerated during the procedures. Fractional flow reserves measured by IC adenosine infusion with 180, 240, 300, and 360 microg/min were significantly lower than those by IV infusion (P < .05). Intracoronary infusion at 180, 240, 300, and 360 microg/min was able to shorten the times to induction of optimal and steady-stable hyperemia compared to IV infusion (P < .05). Functional significances were changed in 5 lesions by IC infusion at 240 to 360 microg/min but not by IV infusion.
  
  
  CONCLUSIONS
  The results of this study suggest that an IC adenosine continuous infusion method via a microcatheter is safe and effective in inducing steady-state hyperemia and more potent and quicker in inducing optimal hyperemia than the standard IV infusion method.
authors.affiliation: Department of Cardiology, School of Medicine, Ajou University, Suwon, Korea.
authors.forename: Myeong-Ho
authors.initials: MH
authors.lastname: Yoon
authors.forename: Seung-Jea
authors.initials: SJ
authors.lastname: Tahk
authors.forename: Hyoung-Mo
authors.initials: HM
authors.lastname: Yang
authors.forename: Jin-Sun
authors.initials: JS
authors.lastname: Park
authors.forename: Mingri
authors.initials: M
authors.lastname: Zheng
authors.forename: Hong-Seok
authors.initials: HS
authors.lastname: Lim
authors.forename: Byoung-Joo
authors.initials: BJ
authors.lastname: Choi
authors.forename: So-Yeon
authors.initials: SY
authors.lastname: Choi
authors.forename: Un-Jung
authors.initials: UJ
authors.lastname: Choi
authors.forename: Joung-Won
authors.initials: JW
authors.lastname: Hwang
authors.forename: Soo-Jin
authors.initials: SJ
authors.lastname: Kang
authors.forename: Gyo-Seung
authors.initials: GS
authors.lastname: Hwang
authors.forename: Joon-Han
authors.initials: JH
authors.lastname: Shin
mesh_terms: D000241:Adenosine / Q000008:administration & dosage*; D000368:Aged; D003326:Coronary Circulation / Q000187:drug effects; D003331:Coronary Vessels / Q000187:drug effects; D003935:Diagnostic Techniques, Cardiovascular; D005260:Female; D006439:Hemodynamics; D006801:Humans; D006940:Hyperemia / Q000139:chemically induced*; D007261:Infusions, Intra-Arterial; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000008:administration & dosage*
chemical_list: D014665:Vasodilator Agents; D000241:Adenosine