Pressure gradient vs. flow relationships to characterize the physiology of a severely stenotic aortic valve before and after transcatheter valve implantation

Nils P. Johnson, Jo M. Zelis, Pim A.L. Tonino (Corresponding author), Patrick Houthuizen, R. Arthur Bouwman, Guus R.G. Brueren, Daniel T. Johnson, Jacques J. Koolen, H.H.M. Korsten, Inge F. Wijnbergen, Frederik M. Zimmermann, Richard L. Kirkeeide, Nico H.J. Pijls, K. Lance Gould

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3 Citaties (Scopus)

Uittreksel

Aims: Echocardiography and tomographic imaging have documented dynamic changes in aortic stenosis (AS) geometry and severity during both the cardiac cycle and stress-induced increases in cardiac output. However, corresponding pressure gradient vs. flow relationships have not been described.

Methods and results: We recruited 16 routine transcatheter aortic valve implantations (TAVI's) for graded dobutamine infusions both before and after implantation; 0.014″ pressure wires in the aorta and left ventricle (LV) continuously measured the transvalvular pressure gradient (ΔP) while a pulmonary artery catheter regularly assessed cardiac output by thermodilution. Before TAVI, ΔP did not display a consistent relationship with transvalvular flow (Q). Neither linear resistor (median R2 0.16) nor quadratic orifice (median R2 < 0.01) models at rest predicted stress observations; the severely stenotic valve behaved like a combination. The unitless ratio of aortic to left ventricular pressures during systolic ejection under stress conditions correlated best with post-TAVI flow improvement. After TAVI, a highly linear relationship (median R2 0.96) indicated a valid valve resistance.

Conclusion: Pressure loss vs. flow curves offer a fundamental fluid dynamic synthesis for describing aortic valve pathophysiology. Severe AS does not consistently behave like an orifice (as suggested by Gorlin) or a resistor, whereas TAVI devices behave like a pure resistor. During peak dobutamine, the ratio of aortic to left ventricular pressures during systolic ejection provides a 'fractional flow reserve' of the aortic valve that closely approximates the complex, changing fluid dynamics. Because resting assessment cannot reliably predict stress haemodynamics, 'valvular fractional flow' warrants study to explain exertional symptoms in patients with only moderate AS at rest.

TaalEngels
Pagina's2646-2655
Aantal pagina's10
TijdschriftEuropean Heart Journal
Volume39
Nummer van het tijdschrift28
DOI's
StatusGepubliceerd - 21 jul 2018

Vingerafdruk

Aortic Valve
Aortic Valve Stenosis
Pressure
Dobutamine
Ventricular Pressure
Hydrodynamics
Cardiac Output
Thermodilution
Pulmonary Artery
Heart Ventricles
Echocardiography
Aorta
Catheters
Hemodynamics
Transcatheter Aortic Valve Replacement
Equipment and Supplies

Citeer dit

Johnson, Nils P. ; Zelis, Jo M. ; Tonino, Pim A.L. ; Houthuizen, Patrick ; Bouwman, R. Arthur ; Brueren, Guus R.G. ; Johnson, Daniel T. ; Koolen, Jacques J. ; Korsten, H.H.M. ; Wijnbergen, Inge F. ; Zimmermann, Frederik M. ; Kirkeeide, Richard L. ; Pijls, Nico H.J. ; Gould, K. Lance. / Pressure gradient vs. flow relationships to characterize the physiology of a severely stenotic aortic valve before and after transcatheter valve implantation. In: European Heart Journal. 2018 ; Vol. 39, Nr. 28. blz. 2646-2655
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title = "Pressure gradient vs. flow relationships to characterize the physiology of a severely stenotic aortic valve before and after transcatheter valve implantation",
abstract = "Aims: Echocardiography and tomographic imaging have documented dynamic changes in aortic stenosis (AS) geometry and severity during both the cardiac cycle and stress-induced increases in cardiac output. However, corresponding pressure gradient vs. flow relationships have not been described.Methods and results: We recruited 16 routine transcatheter aortic valve implantations (TAVI's) for graded dobutamine infusions both before and after implantation; 0.014″ pressure wires in the aorta and left ventricle (LV) continuously measured the transvalvular pressure gradient (ΔP) while a pulmonary artery catheter regularly assessed cardiac output by thermodilution. Before TAVI, ΔP did not display a consistent relationship with transvalvular flow (Q). Neither linear resistor (median R2 0.16) nor quadratic orifice (median R2 < 0.01) models at rest predicted stress observations; the severely stenotic valve behaved like a combination. The unitless ratio of aortic to left ventricular pressures during systolic ejection under stress conditions correlated best with post-TAVI flow improvement. After TAVI, a highly linear relationship (median R2 0.96) indicated a valid valve resistance.Conclusion: Pressure loss vs. flow curves offer a fundamental fluid dynamic synthesis for describing aortic valve pathophysiology. Severe AS does not consistently behave like an orifice (as suggested by Gorlin) or a resistor, whereas TAVI devices behave like a pure resistor. During peak dobutamine, the ratio of aortic to left ventricular pressures during systolic ejection provides a 'fractional flow reserve' of the aortic valve that closely approximates the complex, changing fluid dynamics. Because resting assessment cannot reliably predict stress haemodynamics, 'valvular fractional flow' warrants study to explain exertional symptoms in patients with only moderate AS at rest.",
author = "Johnson, {Nils P.} and Zelis, {Jo M.} and Tonino, {Pim A.L.} and Patrick Houthuizen and Bouwman, {R. Arthur} and Brueren, {Guus R.G.} and Johnson, {Daniel T.} and Koolen, {Jacques J.} and H.H.M. Korsten and Wijnbergen, {Inge F.} and Zimmermann, {Frederik M.} and Kirkeeide, {Richard L.} and Pijls, {Nico H.J.} and Gould, {K. Lance}",
year = "2018",
month = "7",
day = "21",
doi = "10.1093/eurheartj/ehy126",
language = "English",
volume = "39",
pages = "2646--2655",
journal = "European Heart Journal",
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Johnson, NP, Zelis, JM, Tonino, PAL, Houthuizen, P, Bouwman, RA, Brueren, GRG, Johnson, DT, Koolen, JJ, Korsten, HHM, Wijnbergen, IF, Zimmermann, FM, Kirkeeide, RL, Pijls, NHJ & Gould, KL 2018, 'Pressure gradient vs. flow relationships to characterize the physiology of a severely stenotic aortic valve before and after transcatheter valve implantation' European Heart Journal, vol. 39, nr. 28, blz. 2646-2655. DOI: 10.1093/eurheartj/ehy126

Pressure gradient vs. flow relationships to characterize the physiology of a severely stenotic aortic valve before and after transcatheter valve implantation. / Johnson, Nils P.; Zelis, Jo M.; Tonino, Pim A.L. (Corresponding author); Houthuizen, Patrick; Bouwman, R. Arthur; Brueren, Guus R.G.; Johnson, Daniel T.; Koolen, Jacques J.; Korsten, H.H.M.; Wijnbergen, Inge F.; Zimmermann, Frederik M.; Kirkeeide, Richard L.; Pijls, Nico H.J.; Gould, K. Lance.

In: European Heart Journal, Vol. 39, Nr. 28, 21.07.2018, blz. 2646-2655.

Onderzoeksoutput: Bijdrage aan tijdschriftTijdschriftartikelAcademicpeer review

TY - JOUR

T1 - Pressure gradient vs. flow relationships to characterize the physiology of a severely stenotic aortic valve before and after transcatheter valve implantation

AU - Johnson,Nils P.

AU - Zelis,Jo M.

AU - Tonino,Pim A.L.

AU - Houthuizen,Patrick

AU - Bouwman,R. Arthur

AU - Brueren,Guus R.G.

AU - Johnson,Daniel T.

AU - Koolen,Jacques J.

AU - Korsten,H.H.M.

AU - Wijnbergen,Inge F.

AU - Zimmermann,Frederik M.

AU - Kirkeeide,Richard L.

AU - Pijls,Nico H.J.

AU - Gould,K. Lance

PY - 2018/7/21

Y1 - 2018/7/21

N2 - Aims: Echocardiography and tomographic imaging have documented dynamic changes in aortic stenosis (AS) geometry and severity during both the cardiac cycle and stress-induced increases in cardiac output. However, corresponding pressure gradient vs. flow relationships have not been described.Methods and results: We recruited 16 routine transcatheter aortic valve implantations (TAVI's) for graded dobutamine infusions both before and after implantation; 0.014″ pressure wires in the aorta and left ventricle (LV) continuously measured the transvalvular pressure gradient (ΔP) while a pulmonary artery catheter regularly assessed cardiac output by thermodilution. Before TAVI, ΔP did not display a consistent relationship with transvalvular flow (Q). Neither linear resistor (median R2 0.16) nor quadratic orifice (median R2 < 0.01) models at rest predicted stress observations; the severely stenotic valve behaved like a combination. The unitless ratio of aortic to left ventricular pressures during systolic ejection under stress conditions correlated best with post-TAVI flow improvement. After TAVI, a highly linear relationship (median R2 0.96) indicated a valid valve resistance.Conclusion: Pressure loss vs. flow curves offer a fundamental fluid dynamic synthesis for describing aortic valve pathophysiology. Severe AS does not consistently behave like an orifice (as suggested by Gorlin) or a resistor, whereas TAVI devices behave like a pure resistor. During peak dobutamine, the ratio of aortic to left ventricular pressures during systolic ejection provides a 'fractional flow reserve' of the aortic valve that closely approximates the complex, changing fluid dynamics. Because resting assessment cannot reliably predict stress haemodynamics, 'valvular fractional flow' warrants study to explain exertional symptoms in patients with only moderate AS at rest.

AB - Aims: Echocardiography and tomographic imaging have documented dynamic changes in aortic stenosis (AS) geometry and severity during both the cardiac cycle and stress-induced increases in cardiac output. However, corresponding pressure gradient vs. flow relationships have not been described.Methods and results: We recruited 16 routine transcatheter aortic valve implantations (TAVI's) for graded dobutamine infusions both before and after implantation; 0.014″ pressure wires in the aorta and left ventricle (LV) continuously measured the transvalvular pressure gradient (ΔP) while a pulmonary artery catheter regularly assessed cardiac output by thermodilution. Before TAVI, ΔP did not display a consistent relationship with transvalvular flow (Q). Neither linear resistor (median R2 0.16) nor quadratic orifice (median R2 < 0.01) models at rest predicted stress observations; the severely stenotic valve behaved like a combination. The unitless ratio of aortic to left ventricular pressures during systolic ejection under stress conditions correlated best with post-TAVI flow improvement. After TAVI, a highly linear relationship (median R2 0.96) indicated a valid valve resistance.Conclusion: Pressure loss vs. flow curves offer a fundamental fluid dynamic synthesis for describing aortic valve pathophysiology. Severe AS does not consistently behave like an orifice (as suggested by Gorlin) or a resistor, whereas TAVI devices behave like a pure resistor. During peak dobutamine, the ratio of aortic to left ventricular pressures during systolic ejection provides a 'fractional flow reserve' of the aortic valve that closely approximates the complex, changing fluid dynamics. Because resting assessment cannot reliably predict stress haemodynamics, 'valvular fractional flow' warrants study to explain exertional symptoms in patients with only moderate AS at rest.

U2 - 10.1093/eurheartj/ehy126

DO - 10.1093/eurheartj/ehy126

M3 - Article

VL - 39

SP - 2646

EP - 2655

JO - European Heart Journal

T2 - European Heart Journal

JF - European Heart Journal

SN - 0195-668X

IS - 28

ER -