title: Transcatheter Replacement of Stenotic Aortic Valve Normalizes Cardiac-Coronary Interaction by Restoration of Systolic Coronary Flow Dynamics as Assessed by Wave Intensity Analysis.
abstract: BACKGROUND
  Aortic valve stenosis (AS) can cause angina despite unobstructed coronary arteries, which may be related to increased compression of the intramural microcirculation, especially at the subendocardium. We assessed coronary wave intensity and phasic flow velocity patterns to unravel changes in cardiac-coronary interaction because of transcatheter aortic valve implantation (TAVI).
  
  
  RESULTS
  Intracoronary pressure and flow velocity were measured at rest and maximal hyperemia in undiseased vessels in 15 patients with AS before and after TAVI and in 12 control patients. Coronary flow reserve, systolic and diastolic velocity time integrals, and the energies of forward (aorta-originating) and backward (microcirculatory-originating) coronary waves were determined. Coronary flow reserve was 2.8±0.2 (mean±SEM) in control and 1.8±0.1 in AS (P<0.005) and was not restored by TAVI. Compared with control, the resting backward expansion wave was 45% higher in AS. The peak of the systolic forward compression wave was delayed in AS, consistent with a delayed peak aortic pressure, which was partially restored after TAVI. The energy of forward waves doubled after TAVI, whereas the backward expansion wave increased by >30%. The increase in forward compression wave with TAVI was related to an increase in systolic velocity time integral. AS or TAVI did not alter diastolic velocity time integral.
  
  
  CONCLUSIONS
  Reduced coronary forward wave energy and systolic velocity time integral imply a compromised systolic flow velocity with AS that is restored after TAVI, suggesting an acute relief of excess compression in systole that likely benefits subendocardial perfusion. Vasodilation is observed to be a major determinant of backward waves.
authors.affiliation: From the Departments of Biomedical Engineering and Physics (M.C.R., L.C., J.A.E.S., M.S.) and Cardiology (E.M.A.W., Z.-Y.Y., K.T.K., M.V., J.J.P., J.B.), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: M Cristina
authors.initials: MC
authors.lastname: Rolandi
authors.affiliation: From the Departments of Biomedical Engineering and Physics (M.C.R., L.C., J.A.E.S., M.S.) and Cardiology (E.M.A.W., Z.-Y.Y., K.T.K., M.V., J.J.P., J.B.), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Esther M A
authors.initials: EM
authors.lastname: Wiegerinck
authors.affiliation: From the Departments of Biomedical Engineering and Physics (M.C.R., L.C., J.A.E.S., M.S.) and Cardiology (E.M.A.W., Z.-Y.Y., K.T.K., M.V., J.J.P., J.B.), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Lorena
authors.initials: L
authors.lastname: Casadonte
authors.affiliation: From the Departments of Biomedical Engineering and Physics (M.C.R., L.C., J.A.E.S., M.S.) and Cardiology (E.M.A.W., Z.-Y.Y., K.T.K., M.V., J.J.P., J.B.), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Ze-Yie
authors.initials: ZY
authors.lastname: Yong
authors.affiliation: From the Departments of Biomedical Engineering and Physics (M.C.R., L.C., J.A.E.S., M.S.) and Cardiology (E.M.A.W., Z.-Y.Y., K.T.K., M.V., J.J.P., J.B.), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Karel T
authors.initials: KT
authors.lastname: Koch
authors.affiliation: From the Departments of Biomedical Engineering and Physics (M.C.R., L.C., J.A.E.S., M.S.) and Cardiology (E.M.A.W., Z.-Y.Y., K.T.K., M.V., J.J.P., J.B.), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Marije
authors.initials: M
authors.lastname: Vis
authors.affiliation: From the Departments of Biomedical Engineering and Physics (M.C.R., L.C., J.A.E.S., M.S.) and Cardiology (E.M.A.W., Z.-Y.Y., K.T.K., M.V., J.J.P., J.B.), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Piek
authors.affiliation: From the Departments of Biomedical Engineering and Physics (M.C.R., L.C., J.A.E.S., M.S.) and Cardiology (E.M.A.W., Z.-Y.Y., K.T.K., M.V., J.J.P., J.B.), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: Baan
authors.affiliation: From the Departments of Biomedical Engineering and Physics (M.C.R., L.C., J.A.E.S., M.S.) and Cardiology (E.M.A.W., Z.-Y.Y., K.T.K., M.V., J.J.P., J.B.), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Jos A E
authors.initials: JA
authors.lastname: Spaan
authors.affiliation: From the Departments of Biomedical Engineering and Physics (M.C.R., L.C., J.A.E.S., M.S.) and Cardiology (E.M.A.W., Z.-Y.Y., K.T.K., M.V., J.J.P., J.B.), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands. m.siebes@amc.uva.nl.
authors.forename: Maria
authors.initials: M
authors.lastname: Siebes
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000503:physiopathology*; D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D001783:Blood Flow Velocity; D006328:Cardiac Catheterization / Q000295:instrumentation; D016022:Case-Control Studies; D017023:Coronary Angiography; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation / Q000379:methods*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011673:Pulsatile Flow; D020127:Recovery of Function; D013599:Systole; D013997:Time Factors; D016896:Treatment Outcome; D014664:Vasodilation
keywords: aortic valve stenosis; cardiac–coronary interaction; coronary flow; transcatheter aortic valve implantation; wave intensity