title: Maximal hyperemia in the assessment of fractional flow reserve: intracoronary adenosine versus intracoronary sodium nitroprusside versus intravenous adenosine: the NASCI (Nitroprussiato versus Adenosina nelle Stenosi Coronariche Intermedie) study.
abstract: OBJECTIVE
  This study sought to compare increasing doses of intracoronary (i.c.) adenosine or i.c. sodium nitroprusside versus intravenous (i.v.) adenosine for fractional flow reserve (FFR) assessment.
  
  
  BACKGROUND
  Maximal hyperemia is the critical prerequisite for FFR assessment. Despite i.v. adenosine currently representing the recommended approach, i.c. administration of adenosine or other coronary vasodilators constitutes a valuable alternative in everyday practice. However, it is surprisingly unclear which i.c. strategy allows the achievement of FFR values comparable to i.v. adenosine.
  
  
  METHODS
  Fifty intermediate coronary stenoses (n = 45) undergoing FFR measurement were prospectively and consecutively enrolled. Hyperemia was sequentially induced by incremental boli of i.c. adenosine (ADN) (60 μg ADN60, 300 μg ADN300, 600 μg ADN600), by i.c. sodium nitroprusside (NTP) (0.6 μg/kg bolus) and by i.v. adenosine infusion (IVADN) (140 μg/kg/min). FFR values, symptoms, and development of atrioventricular block were recorded.
  
  
  RESULTS
  Incremental doses of i.c. adenosine and NTP were well tolerated and associated with fewer symptoms than IVADN. Intracoronary adenosine doses (0.881 ± 0.067, 0.871 ± 0.068, and 0.868 ± 0.070 with ADN60, ADN300, and ADN600, respectively) and NTP (0.892 ± 0.072) induced a significant decrease of FFR compared with baseline levels (p < 0.001). Notably, ADN600 only was associated with FFR values similar to IVADN (0.867 ± 0.072, p = 0.28). Among the 10 patients with FFR values ≤0.80 with IVADN, 5 were correctly identified also by ADN60, 6 by ADN300, 7 by ADN600, and 6 by NTP.
  
  
  CONCLUSIONS
  Intracoronary adenosine, at doses higher than currently suggested, allows obtaining FFR values similar to i.v. adenosine. Intravenous adenosine, which remains the gold standard, might thus be reserved for those lesions with equivocal FFR values after high (up to 600 μg) i.c. adenosine doses.
authors.affiliation: Department of Cardiovascular Medicine, Catholic University of the Sacred Heart, Rome, Italy. antoniomarialeone@gmail.com
authors.forename: Antonio Maria
authors.initials: AM
authors.lastname: Leone
authors.forename: Italo
authors.initials: I
authors.lastname: Porto
authors.forename: Alberto Ranieri
authors.initials: AR
authors.lastname: De Caterina
authors.forename: Eloisa
authors.initials: E
authors.lastname: Basile
authors.forename: Andrea
authors.initials: A
authors.lastname: Aurelio
authors.forename: Andrea
authors.initials: A
authors.lastname: Gardi
authors.forename: Dolores
authors.initials: D
authors.lastname: Russo
authors.forename: Domenico
authors.initials: D
authors.lastname: Laezza
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Niccoli
authors.forename: Francesco
authors.initials: F
authors.lastname: Burzotta
authors.forename: Carlo
authors.initials: C
authors.lastname: Trani
authors.forename: Mario Attilio
authors.initials: MA
authors.lastname: Mazzari
authors.forename: Rocco
authors.initials: R
authors.lastname: Mongiardo
authors.forename: Antonio Giuseppe
authors.initials: AG
authors.lastname: Rebuzzi
authors.forename: Filippo
authors.initials: F
authors.lastname: Crea
mesh_terms: D000241:Adenosine / Q000008:administration & dosage / Q000009:adverse effects; D000368:Aged; D000465:Algorithms; D054537:Atrioventricular Block / Q000139:chemically induced; D006328:Cardiac Catheterization; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D004305:Dose-Response Relationship, Drug; D005260:Female; D053805:Fractional Flow Reserve, Myocardial / Q000187:drug effects*; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology*; D007261:Infusions, Intra-Arterial; D007262:Infusions, Intravenous; D007269:Injections, Intra-Arterial; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D009599:Nitroprusside / Q000008:administration & dosage / Q000009:adverse effects; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012384:Rome; D012720:Severity of Illness Index; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000009:adverse effects
chemical_list: D014665:Vasodilator Agents; D009599:Nitroprusside; D000241:Adenosine