title: Stent implantation alters coronary artery hemodynamics and wall shear stress during maximal vasodilation.
abstract: Coronary stents improve resting blood flow and flow reserve in the presence of stenoses, but the impact of these devices on fluid dynamics during profound vasodilation is largely unknown. We tested the hypothesis that stent implantation affects adenosine-induced alterations in coronary hemodynamics and wall shear stress in anesthetized dogs (n = 6) instrumented for measurement of left anterior descending coronary artery (LAD) blood flow, velocity, diameter, and radius of curvature. Indexes of fluid dynamics and shear stress were determined before and after placement of a slotted-tube stent in the absence and presence of an adenosine infusion (1.0 mg/min). Adenosine increased blood flow, Reynolds (Re) and Dean numbers (De), and regional and oscillatory shear stress concomitant with reductions in LAD vascular resistance and segmental compliance before stent implantation. Increases in LAD blood flow, Re, De, and indexes of shear stress were observed after stent deployment (P < 0.05). Stent implantation reduced LAD segmental compliance to zero and potentiated increases in segmental and coronary vascular resistance during adenosine. Adenosine-induced increases in coronary blood flow and reserve, Re, De, and regional and oscillatory shear stress were attenuated after the stent was implanted. The results indicate that stent implantation blunts alterations in fluid dynamics during coronary vasodilation in vivo.
authors.affiliation: Department of Anesthesiology, Medical College of Wisconsin and the Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee 53226, USA.
authors.forename: John F
authors.initials: JF
authors.lastname: LaDisa
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Hettrick
authors.forename: Lars E
authors.initials: LE
authors.lastname: Olson
authors.forename: Ismail
authors.initials: I
authors.lastname: Guler
authors.forename: Eric R
authors.initials: ER
authors.lastname: Gross
authors.forename: Tobias T
authors.initials: TT
authors.lastname: Kress
authors.forename: Judy R
authors.initials: JR
authors.lastname: Kersten
authors.forename: David C
authors.initials: DC
authors.lastname: Warltier
authors.forename: Paul S
authors.initials: PS
authors.lastname: Pagel
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000758:Anesthesia; D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects / Q000502:physiology; D003326:Coronary Circulation / Q000187:drug effects / Q000502:physiology*; D004285:Dogs; D005260:Female; D017078:Laser-Doppler Flowmetry / Q000295:instrumentation / Q000379:methods; D008297:Male; D015607:Stents; D013314:Stress, Mechanical; D014655:Vascular Resistance / Q000502:physiology; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D014665:Vasodilator Agents; D000241:Adenosine