title: Simultaneous intracoronary velocity- and pressure-derived assessment of adenosine-induced collateral hemodynamics in patients with one- to two-vessel coronary artery disease.
abstract: OBJECTIVE
  The purpose of this investigation in patients with poorly and well developed coronary collaterals was to assess the influence of collateral and collateral adjacent vascular resistances and, in part, a stenotic lesion of the collateral supplying vessel on the hemodynamic collateral responses to adenosine.
  
  
  BACKGROUND
  In humans, little is known about the functional behavior of the coronary collateral circulation.
  
  
  METHODS
  In 50 patients with one- and two-vessel coronary artery disease (CAD) undergoing percutaneous transluminal coronary angioplasty (PTCA), collateral flow index (CFI, no unit) changes and vascular resistance index (R, cm/mm Hg) changes of the collateral (R(coll)) and the distal collateral receiving (R4) vessel in response to adenosine (140 microg/min/kg IV) were measured by intracoronary (i.c.) Doppler and pressure guidewires. The variables were determined at baseline and during adenosine in patients with poor (angiographic collateral degree before PTCA <2 of 0 to 3) and good coronary collaterals.
  
  
  RESULTS
  Pressure-derived CFI (CFI(p)) decreased under adenosine in patients with poor collaterals, and it increased in the group with good collaterals. There were inverse correlations between the adenosine-induced change in CFI(p) and the change in R(coll) (r = 0.61, p = 0.0001). In the group with good, but not with poor collaterals, there was also a significant correlation between CFI(p) increase and the decrease in R4, between the severity of the contralateral stenosis and CFI(p) augmentation and among the left versus right coronary artery as ipsilateral vessel and CFI(p) change.
  
  
  CONCLUSIONS
  Overall, patients with well, versus poorly developed coronary collaterals do better regarding the capacity to increase collateral flow in response to adenosine. In patients with good, but not poor, collaterals, an adenosine-induced collateral flow increase depends on the ipsilateral distal vascular resistance decrease, but is also directly influenced by the severity of a contralateral stenosis and probably by the size of the collateralized vascular bed.
authors.affiliation: Division of Cardiology, University Hospital, Swiss Cardiovascular Center Bern, Switzerland. christian.seiler.cardio@insel.ch
authors.forename: C
authors.initials: C
authors.lastname: Seiler
authors.forename: M
authors.initials: M
authors.lastname: Fleisch
authors.forename: M
authors.initials: M
authors.lastname: Billinger
authors.forename: B
authors.initials: B
authors.lastname: Meier
mesh_terms: D000241:Adenosine / Q000008:administration & dosage*; D015906:Angioplasty, Balloon, Coronary; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D006328:Cardiac Catheterization; D003097:Collateral Circulation / Q000187:drug effects*; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000187:drug effects*; D003327:Coronary Disease / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000187:drug effects*; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D018084:Ultrasonography, Interventional; D014655:Vascular Resistance / Q000187:drug effects; D014665:Vasodilator Agents / Q000008:administration & dosage*
chemical_list: D014665:Vasodilator Agents; D000241:Adenosine