This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Blais, C. Articles by Pibarot, P. Search for Related Content PubMed PubMed Citation Articles by Blais, C. Articles by Pibarot, P. Related Collections Valvular heart disease Echocardiography CV surgery: valvular disease

(Circulation. 2006;113:711-721.)
© 2006 American Heart Association, Inc.

Valvular Heart Disease

Projected Valve Area at Normal Flow Rate Improves the Assessment of Stenosis Severity in Patients With Low-Flow, Low-Gradient Aortic Stenosis

The Multicenter TOPAS (Truly or Pseudo-Severe Aortic Stenosis) Study

Claudia Blais, MSc; Ian G. Burwash, MD; Gerald Mundigler, MD; Jean G. Dumesnil, MD; Nicole Loho, MD; Florian Rader, MD; Helmut Baumgartner, MD; Rob S. Beanlands, MD; Boris Chayer, Eng; Lyes Kadem, Eng, PhD; Damien Garcia, Eng, PhD; Louis-Gilles Durand, Eng, PhD; Philippe Pibarot, DVM, PhD

From the Research Center of Laval Hospital/Quebec Heart Institute, Laval University, Sainte-Foy, Quebec, Canada (C.B., J.G.D., P.P.); University of Ottawa Heart Institute, Ottawa, Ontario, Canada (I.G.B., R.S.B.); Vienna General Hospital, Medical University of Vienna, Vienna, Austria (G.M., N.L., F.R., H.B.); and Institut de Recherches Cliniques de Montréal, Montreal, Quebec, Canada (B.C., L.K., D.G., L.D.).

Reprint requests to Dr Philippe Pibarot, Quebec Heart Institute, 2725 Chemin Sainte-Foy, Sainte-Foy G1V-4G5, Quebec, Canada. E-mail philippe.pibarot{at}med.ulaval.ca

Received April 30, 2005; revision received October 3, 2005; accepted October 28, 2005.

Background— We sought to investigate the use of a new parameter, the projected effective orifice area (EOA_proj) at normal transvalvular flow rate (250 mL/s), to better differentiate between truly severe (TS) and pseudo-severe (PS) aortic stenosis (AS) during dobutamine stress echocardiography (DSE). Changes in various parameters of stenosis severity have been used to differentiate between TS and PS AS during DSE. However, the magnitude of these changes lacks standardization because they are dependent on the variable magnitude of the transvalvular flow change occurring during DSE.

Methods and Results— The use of EOA_proj to differentiate TS from PS AS was investigated in an in vitro model and in 23 patients with low-flow AS (indexed EOA <0.6 cm²/m², left ventricular ejection fraction 40%) undergoing DSE and subsequent aortic valve replacement. For an individual valve, EOA was plotted against transvalvular flow (Q) at each dobutamine stage, and valve compliance (VC) was derived as the slope of the regression line fitted to the EOA versus Q plot; EOA_proj was calculated as EOA_proj=EOA_rest+VCx(250–Q_rest), where EOA_rest and Q_rest are the EOA and Q at rest. Classification between TS and PS was based on either response to flow increase (in vitro) or visual inspection at surgery (in vivo). EOA_proj was the most accurate parameter in differentiating between TS and PS both in vitro and in vivo. In vivo, 15 of 23 patients (65%) had TS and 8 of 23 (35%) had PS. The percentage of correct classification was 83% for EOA_proj and 91% for indexed EOA_proj compared with percentages of 61% to 74% for the other echocardiographic parameters usually used for this purpose.

Conclusions— EOA_proj provides a standardized evaluation of AS severity with DSE and improves the diagnostic accuracy for distinguishing TS and PS AS in patients with low-flow, low-gradient AS.

---

 

CLINICAL PERSPECTIVE

This article has been cited by other articles:

				P V Ennezat, S Marechaux, B Iung, C Chauvel, T H LeJemtel, and P Pibarot Exercise testing and exercise stress echocardiography in asymptomatic aortic valve stenosis Heart, June 1, 2009; 95(11): 877 - 884. [Abstract] [Full Text] [PDF]

				H. Baumgartner, J. Hung, J. Bermejo, J. B. Chambers, A. Evangelista, B. P. Griffin, B. Iung, C. M. Otto, P. A. Pellikka, and M. Quinones Echocardiographic assessment of valve stenosis: EAE/ASE recommendations for clinical practice Eur J Echocardiogr, January 1, 2009; 10(1): 1 - 25. [Full Text] [PDF]

				I G Burwash, M Lortie, P Pibarot, R A de Kemp, S Graf, G Mundigler, A Khorsand, C Blais, H Baumgartner, J G Dumesnil, et al. Myocardial blood flow in patients with low-flow, low-gradient aortic stenosis: differences between true and pseudo-severe aortic stenosis. Results from the multicentre TOPAS (Truly or Pseudo-Severe Aortic Stenosis) study Heart, December 1, 2008; 94(12): 1627 - 1633. [Abstract] [Full Text] [PDF]

				C. Tribouilloy and F. Levy Assessment and management of low-gradient, low ejection fraction aortic stenosis Heart, December 1, 2008; 94(12): 1526 - 1527. [Full Text] [PDF]

				M.-A. Clavel, C. Fuchs, I. G. Burwash, G. Mundigler, J. G. Dumesnil, H. Baumgartner, J. Bergler-Klein, R. S. Beanlands, P. Mathieu, J. Magne, et al. Predictors of Outcomes in Low-Flow, Low-Gradient Aortic Stenosis: Results of the Multicenter TOPAS Study Circulation, September 30, 2008; 118(14_suppl_1): S234 - S242. [Abstract] [Full Text] [PDF]

				B. A. Carabello Aortic Stenosis: Two Steps Forward, One Step Back Circulation, June 5, 2007; 115(22): 2799 - 2800. [Full Text] [PDF]

				J. Bergler-Klein, G. Mundigler, P. Pibarot, I. G. Burwash, J. G. Dumesnil, C. Blais, C. Fuchs, D. Mohty, R. S. Beanlands, Z. Hachicha, et al. B-Type Natriuretic Peptide in Low-Flow, Low-Gradient Aortic Stenosis: Relationship to Hemodynamics and Clinical Outcome: Results From the Multicenter Truly or Pseudo-Severe Aortic Stenosis (TOPAS) Study Circulation, June 5, 2007; 115(22): 2848 - 2855. [Abstract] [Full Text] [PDF]

				Z. Hachicha, J. G. Dumesnil, P. Bogaty, and P. Pibarot Paradoxical Low-Flow, Low-Gradient Severe Aortic Stenosis Despite Preserved Ejection Fraction Is Associated With Higher Afterload and Reduced Survival Circulation, June 5, 2007; 115(22): 2856 - 2864. [Abstract] [Full Text] [PDF]

				A. F.L. Schinkel, M. Bountioukos, D. Poldermans, and J. J. Bax Letter by Schinkel et al Regarding Article, "Projected Valve Area at Normal Flow Rate Improves the Assessment of Stenosis Severity in Patients With Low-Flow, Low-Gradient Aortic Stenosis: The Multicenter TOPAS (Truly or Pseudo-Severe Aortic Stenosis) Study" Circulation, October 3, 2006; 114(14): e526 - e526. [Full Text] [PDF]

				P. Pibarot, C. Blais, J. G. Dumesnil, I. G. Burwash, R. S. Beanlands, G. Mundigler, N. Loho, F. Rader, H. Baumgartner, B. Chayer, et al. Response to Letter Regarding Article, "Projected Valve Area at Normal Flow Rate Improves the Assessment of Stenosis Severity in Patients With Low-Flow, Low-Gradient Aortic Stenosis: The Multicenter TOPAS (Truly or Pseudo-Severe Aortic Stenosis) Study" Circulation, October 3, 2006; 114(14): e527 - e527. [Full Text] [PDF]

				P. A. Grayburn Assessment of Low-Gradient Aortic Stenosis With Dobutamine Circulation, February 7, 2006; 113(5): 604 - 606. [Full Text] [PDF]