title: Fractional flow reserve: intracoronary versus intravenous adenosine induced maximal coronary hyperemia.
abstract: BACKGROUND
  Fractional Flow Reserve (FFR), a measure of coronary stenosis severity is based on the achievement of maximal hyperemia of coronary microcirculation. The most widely used pharmacological agent is adenosine which is administered either by intra coronary or intra venous routes. IV route is time consuming, has more side effects and expensive. This study is undertaken to compare the two routes of administration.
  
  
  METHODS
  FFR was assessed in 50 patients with 56 intermediate focal lesions using both IV and intracoronary (IC) adenosine. FFR was calculated as the ratio of the distal coronary pressure to the aortic pressure at maximal hyperemia.
  
  
  RESULTS
  A total of 25 left anterior descending, 8 right, 21 circumflex, and 2 left main coronary arteries were evaluated. The mean percent stenosis was 63.91 ± 13.13 SD and, the mean FFR was 0.831 ± 0.0738 SD for IV and 0.832 ± 0.0707 SD for IC adenosine. There was a strong and linear correlation between 2 sets of observations with IV dose and IC adenosine dose (R = 0.964, y = 0.065 + 0.923x; p < 0.001) (y = IV dose, x = IC dose). The agreement between the two sets of measurements was also high, with a mean difference of: 0.001 ± 0.0197. The changes in heart rate and blood pressure were significantly higher in IV adenosine group. Different incremental doses were well tolerated, with fewer systemic adverse events with IC adenosine. Transient AV blocks were observed with both IV and IC adenosine.
  
  
  CONCLUSIONS
  This study suggests that IC adenosine is equivalent to IV infusion for the determination of FFR. The administration of IC adenosine is easy to use, cost effective, safe and associated with fewer systemic events.
authors: Fortis Escorts Heart Institute and Research Center, Okhla Road, New Delhi, India.
authors: P S
authors: PS
authors: Sandhu
authors: Upendra
authors: U
authors: Kaul
authors: R K
authors: RK
authors: Gupta
authors: Tapan
authors: T
authors: Ghose
mesh_terms: D000241:Adenosine / Q000008:administration & dosage*; D003326:Coronary Circulation / Q000187:drug effects; D005260:Female; D053805:Fractional Flow Reserve, Myocardial / Q000187:drug effects*; D006801:Humans; D006940:Hyperemia / Q000139:chemically induced; D007261:Infusions, Intra-Arterial; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D014665:Vasodilator Agents / Q000008:administration & dosage*
chemical_list: D014665:Vasodilator Agents; D000241:Adenosine
references: Circulation. 1996 Oct 15;94(8):1842-9
references: 8873658
references: J Am Coll Cardiol. 1997 Sep;30(3):613-20
references: 9283516
references: JACC Cardiovasc Interv. 2012 Apr;5(4):402-8
references: 22516396
references: Am Heart J. 2000 Oct;140(4):651-7
references: 11011341
references: Circulation. 1995 Dec 1;92(11):3183-93
references: 7586302
references: Circulation. 1990 Nov;82(5):1595-606
references: 2225364
references: Circulation. 2002 Jun 25;105(25):2950-4
references: 12081986
references: Am Heart J. 2004 Oct;148(4):590-5
references: 15459587
references: Circulation. 2000 Mar 21;101(11):1344-51
references: 10725297
references: N Engl J Med. 2009 Jan 15;360(3):213-24
references: 19144937
references: Circulation. 1995 Oct 15;92(8):2333-42
references: 7554219
references: Circulation. 1993 Apr;87(4):1354-67
references: 8462157
references: N Engl J Med. 2012 Sep 13;367(11):991-1001
references: 22924638
references: J Am Coll Cardiol. 1991 Sep;18(3):718-29
references: 1869735
references: Circulation. 2000 Jan 25;101(3):318-23
references: 10645929