B. Iung, G. Baron, E. G. Butchart, F. Delahaye, C. Gohlke-barwolf et al., A prospective survey of patients with valvular heart disease in Europe: The Euro Heart Survey on Valvular Heart Disease, Eur Heart J, vol.24, issue.13, pp.1231-1243, 2003.

R. L. Osnabrugge, D. Mylotte, S. J. Head, N. M. Van-mieghem, V. T. Nkomo et al., Aortic stenosis in the elderly: disease prevalence and number of candidates for transcatheter aortic valve replacement: a meta-analysis and modeling study, J Am Coll Cardiol, vol.62, issue.11, pp.1002-1012, 2013.

B. F. Stewart, D. Siscovick, B. K. Lind, J. M. Gardin, J. S. Gottdiener et al., Clinical factors associated with calcific aortic valve disease. Cardiovascular Health Study, J Am Coll Cardiol, vol.29, issue.3, pp.630-634, 1997.

S. Verma and S. C. Siu, Aortic dilatation in patients with bicuspid aortic valve, N Engl J Med, vol.370, issue.20, pp.1920-1929, 2014.

H. Baumgartner, J. Hung, J. Bermejo, J. B. Chambers, A. Evangelista et al., Echocardiographic assessment of valve stenosis: EAE/ASE recommendations for clinical practice, J Am Soc Echocardiogr, vol.22, issue.1, pp.101-102, 2009.

H. Baumgartner, H. Kratzer, G. Helmreich, and P. Kuehn, Determination of aortic valve area by Doppler echocardiography using the continuity equation: a critical evaluation, Cardiology, vol.77, issue.2, pp.101-111, 1990.

H. Baumgartner, V. Falk, J. J. Bax, M. De, C. Bonis et al., 2017 ESC/EACTS Guidelines for the management of valvular heart disease, Eur Heart J, vol.38, issue.36, pp.2739-2791, 2017.

R. A. Nishimura, C. M. Otto, R. O. Bonow, B. A. Carabello, J. P. Erwin et al., AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines, J Am Coll Cardiol, vol.63, issue.22, pp.57-185, 2014.

T. Taniguchi, T. Morimoto, H. Shiomi, K. Ando, N. Kanamori et al., Initial Surgical Versus Conservative Strategies in Patients With Asymptomatic Severe Aortic Stenosis, J Am Coll Cardiol, vol.66, issue.25, pp.2827-2838, 2015.

R. Rosenhek, T. Binder, G. Porenta, I. Lang, G. Christ et al., Predictors of outcome in severe, asymptomatic aortic stenosis, N Engl J Med, vol.343, issue.9, pp.611-617, 2000.

S. Nishimura, C. Izumi, M. Nishiga, M. Amano, S. Imamura et al., Predictors of Rapid Progression and Clinical Outcome of Asymptomatic Severe Aortic Stenosis, Circ J, vol.80, issue.8, pp.1863-1869, 2016.

J. Bergler-klein, U. Klaar, M. Heger, R. Rosenhek, G. Mundigler et al., Natriuretic peptides predict symptom-free survival and postoperative outcome in severe aortic stenosis, Circulation, vol.109, pp.2302-2308, 2004.
DOI : 10.1016/j.accreview.2004.07.134

D. M. Zlotnick, M. L. Ouellette, D. J. Malenka, J. P. Desimone, B. J. Leavitt et al., Effect of preoperative pulmonary hypertension on outcomes in patients with severe aortic stenosis following surgical aortic valve replacement, Am J Cardiol, vol.112, issue.10, pp.1635-1640, 2013.

A. Cribier, H. Eltchaninoff, A. Bash, N. Borenstein, C. Tron et al., Percutaneous transcatheter implantation of an aortic valve prosthesis for calcific aortic stenosis: first human case description, Circulation, vol.106, issue.24, pp.3006-3008, 2002.

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, vol.115, issue.22, pp.2856-2864, 2007.

J. Minners, M. Allgeier, C. Gohlke-baerwolf, R. P. Kienzle, F. J. Neumann et al.,

. Jander, Inconsistencies of echocardiographic criteria for the grading of aortic valve stenosis, Eur Heart J, vol.29, issue.8, pp.1043-1048, 2008.

M. A. Clavel, J. Magne, and P. Pibarot, Low-gradient aortic stenosis, Eur Heart J, vol.37, issue.34, pp.2645-2657, 2016.

C. Tribouilloy, D. Rusinaru, S. Marechaux, A. L. Castel, N. Debry et al., Low-gradient, low-flow severe aortic stenosis with preserved left ventricular ejection fraction: characteristics, outcome, and implications for surgery, J Am Coll Cardiol, vol.65, issue.1, pp.55-66, 2015.

M. F. Eleid, P. Sorajja, H. I. Michelena, J. F. Malouf, C. G. Scott et al., Flow-gradient patterns in severe aortic stenosis with preserved ejection fraction: clinical characteristics and predictors of survival, Circulation, vol.128, issue.16, pp.1781-1789, 2013.

P. Lancellotti, J. Magne, E. Donal, L. Davin, K. O'connor et al., Clinical outcome in asymptomatic severe aortic stenosis: insights from the new proposed aortic stenosis grading classification, J Am Coll Cardiol, vol.59, issue.3, pp.235-243, 2012.
URL : https://hal.archives-ouvertes.fr/hal-00904869

M. A. Clavel, J. G. Dumesnil, R. Capoulade, P. Mathieu, M. Senechal et al., Outcome of patients with aortic stenosis, small valve area, and low-flow, lowgradient despite preserved left ventricular ejection fraction, J Am Coll Cardiol, vol.60, issue.14, pp.1259-1267, 2012.

J. G. Dumesnil, P. Pibarot, and B. Carabello, Paradoxical low flow and/or low gradient severe aortic stenosis despite preserved left ventricular ejection fraction: implications for diagnosis and treatment, Eur Heart J, vol.31, issue.3, pp.281-289, 2010.

M. A. Clavel, D. Messika-zeitoun, P. Pibarot, S. R. Aggarwal, J. Malouf et al., The complex nature of discordant severe calcified aortic valve disease grading: new insights from combined Doppler echocardiographic and computed tomographic study, J Am Coll Cardiol, vol.62, issue.24, pp.2329-2338, 2013.

V. Dayan, G. Vignolo, J. Magne, M. A. Clavel, D. Mohty et al., Outcome and Impact of Aortic Valve Replacement in Patients With Preserved LVEF and Low-Gradient Aortic Stenosis, J Am Coll Cardiol, vol.66, issue.23, pp.2594-2603, 2015.

A. Ozkan, R. Hachamovitch, S. R. Kapadia, E. M. Tuzcu, and T. H. Marwick, Impact of aortic valve replacement on outcome of symptomatic patients with severe aortic stenosis with low gradient and preserved left ventricular ejection fraction, Circulation, vol.128, issue.6, pp.622-631, 2013.

G. Melis, G. Frontera, G. Caldentey, A. Sahuquillo, C. Fernandez-palomeque et al.,

. Forteza, Systolic volume index by Doppler echocardiography is an useful marker for stratification and prognostic evaluation in patients with severe aortic stenosis and preserved ejection fraction, Rev Esp Cardiol (Engl Ed), vol.66, issue.4, pp.261-268, 2013.

G. Tarantini, E. Covolo, R. Razzolini, C. Bilato, A. C. Frigo et al., Valve replacement for severe aortic stenosis with low transvalvular gradient and left ventricular ejection fraction exceeding 0.50, Ann Thorac Surg, vol.91, issue.6, pp.1808-1815, 2011.

D. Mohty, J. Magne, M. Deltreuil, V. Aboyans, N. Echahidi et al., Outcome and impact of surgery in paradoxical low-flow, low-gradient severe aortic stenosis and preserved left ventricular ejection fraction: a cardiac catheterization study, Circulation, vol.128, issue.11, pp.235-242, 2013.

O. Zusman, G. S. Pressman, S. Banai, A. Finkelstein, and Y. Topilsky, Intervention Versus Observation in Symptomatic Patients With Normal Flow-Low Gradient Severe Aortic Stenosis, JACC Cardiovasc Imaging, 2017.

N. Jander, J. Minners, I. Holme, E. Gerdts, K. Boman et al., Outcome of patients with low-gradient "severe" aortic stenosis and preserved ejection fraction, Circulation, vol.123, issue.8, pp.887-895, 2011.
DOI : 10.1161/circulationaha.110.983510

URL : https://www.ahajournals.org/doi/pdf/10.1161/CIRCULATIONAHA.110.983510

P. Mehrotra, K. Jansen, A. W. Flynn, T. C. Tan, S. Elmariah et al., Differential left ventricular remodelling and longitudinal function distinguishes low flow from normal-flow preserved ejection fraction low-gradient severe aortic stenosis, Eur Heart J, vol.34, issue.25, pp.1906-1914, 2013.
DOI : 10.1093/eurheartj/eht094

URL : https://academic.oup.com/eurheartj/article-pdf/34/25/1906/17896160/eht094.pdf

D. H. Kang, J. Y. Jang, S. J. Park, D. H. Kim, S. C. Yun et al., Watchful observation versus early aortic valve replacement for symptomatic patients with normal flow, low-gradient severe aortic stenosis, Heart, vol.101, issue.17, pp.1375-1381, 2015.
DOI : 10.1136/heartjnl-2015-307528

R. O. Bonow, A. S. Brown, L. D. Gillam, S. R. Kapadia, C. J. Kavinsky et al., Appropriate Use Criteria for the Treatment of Patients With Severe Aortic Stenosis: A Report of the American College of Cardiology Appropriate Use Criteria Task Force, American Association for Thoracic Surgery, J Am Coll Cardiol, vol.70, issue.20, pp.2566-2598, 2017.

M. E. Charlson, P. Pompei, K. L. Ales, and C. R. Mackenzie, A new method of classifying prognostic comorbidity in longitudinal studies: development and validation, J Chronic Dis, vol.40, issue.5, pp.373-383, 1987.

H. C. Baumgartner, J. C. Hung, J. Bermejo, J. B. Chambers, T. Edvardsen et al., Recommendations on the echocardiographic assessment of aortic valve stenosis: a focused update from the European Association of Cardiovascular Imaging and the American Society of Echocardiography, Eur Heart J Cardiovasc Imaging, vol.18, issue.3, pp.254-275, 2017.

P. J. Currie, J. B. Seward, G. S. Reeder, R. E. Vlietstra, D. R. Bresnahan et al., Continuous-wave Doppler echocardiographic assessment of severity of calcific aortic stenosis: a simultaneous Doppler-catheter correlative study in 100 adult patients, Circulation, vol.71, issue.6, pp.1162-1169, 1985.

A. Evangelista, D. Garcia-dorado, H. Garcia-del-castillo, T. Gonzalez-alujas, and J. Soler-soler, Cardiac index quantification by Doppler ultrasound in patients without left ventricular outflow tract abnormalities, J Am Coll Cardiol, vol.25, issue.3, pp.710-716, 1995.
DOI : 10.1016/0735-1097(94)00456-z

URL : https://doi.org/10.1016/0735-1097(94)00456-z

R. M. Lang, L. P. Badano, V. Mor-avi, J. Afilalo, A. Armstrong et al., Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging, Eur Heart J Cardiovasc Imaging, vol.16, issue.3, pp.233-270, 2015.

A. M. Pritchett, S. J. Jacobsen, D. W. Mahoney, R. J. Rodeheffer, K. R. Bailey et al.,

M. Redfield, Left atrial volume as an index of left atrial size: a population-based study, J Am Coll Cardiol, vol.41, issue.6, pp.1036-1043, 2003.

C. Russo, R. T. Hahn, Z. Jin, S. Homma, R. L. Sacco et al., Comparison of echocardiographic single-plane versus biplane method in the assessment of left atrial volume and validation by real time three-dimensional echocardiography, J Am Soc Echocardiogr, vol.23, issue.9, pp.954-960, 2010.

P. G. Yock and R. L. Popp, Noninvasive estimation of right ventricular systolic pressure by Doppler ultrasound in patients with tricuspid regurgitation, Circulation, vol.70, issue.4, pp.657-662, 1984.

A. Vahanian, F. O.-alfieri, M. J. Andreotti, G. Antunes, H. Baron-esquivias et al., Guidelines on the management of valvular heart disease (version 2012): the Joint Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology (ESC) and the European Association for CardioThoracic Surgery (EACTS), Eur J Cardiothorac Surg, vol.42, issue.4, pp.1-44, 2012.

A. Vahanian, H. Baumgartner, J. Bax, E. Butchart, R. Dion et al., Guidelines on the management of valvular heart disease: The Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology, Eur Heart J, vol.28, issue.2, pp.230-268, 2007.

R. O. Bonow, B. Carabello, A. C. De-leon, L. H. Edmunds, B. J. Fedderly et al., ACC/AHA Guidelines for the Management of Patients With Valvular Heart Disease. Executive Summary. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Patients With Valvular Heart Disease), J Heart Valve Dis, vol.7, issue.6, pp.672-707, 1998.

R. B. D'agostino and . Jr, Propensity score methods for bias reduction in the comparison of a treatment to a non-randomized control group, Stat Med, vol.17, pp.2265-2281, 1998.

Y. Mo, M. Penicka, G. D. Gioia, E. Barbato, T. Ondrus et al., Resolving Apparent Inconsistencies Between Area, Flow, and Gradient Measurements in Patients With Aortic Valve Stenosis and Preserved Left Ventricular Ejection Fraction, Am J Cardiol, vol.121, issue.6, pp.751-757, 2018.

A. C. Ng, V. Delgado, F. Van-der-kley, M. Shanks, N. R. Van-de-veire et al., Comparison of aortic root dimensions and geometries before and after transcatheter aortic valve implantation by 2-and 3-dimensional transesophageal echocardiography and multislice computed tomography, Circ Cardiovasc Imaging, vol.3, issue.1, pp.94-102, 2010.
DOI : 10.1161/circimaging.109.885152

URL : https://www.ahajournals.org/doi/pdf/10.1161/CIRCIMAGING.109.885152

S. Doddamani, R. Bello, M. A. Friedman, A. Banerjee, J. H. Bowers et al., Demonstration of left ventricular outflow tract eccentricity by real time 3D echocardiography: implications for the determination of aortic valve area, Echocardiography, vol.24, issue.8, pp.860-866, 2007.

T. Gaspar, S. Adawi, R. Sachner, I. Asmer, M. Ganaeem et al., Three-dimensional imaging of the left ventricular outflow tract: impact on aortic valve area estimation by the continuity equation, J Am Soc Echocardiogr, vol.25, issue.7, pp.749-757, 2012.

C. W. Chin, H. J. Khaw, E. Luo, S. Tan, A. C. White et al., Echocardiography underestimates stroke volume and aortic valve area: implications for patients with small-area low-gradient aortic stenosis, Can J Cardiol, vol.30, issue.9, pp.1064-1072, 2014.

C. De-vecchi, J. Caudron, B. Dubourg, N. Pirot, V. Lefebvre et al., Effect of the ellipsoid shape of the left ventricular outflow tract on the echocardiographic assessment of aortic valve area in aortic stenosis, J Cardiovasc Comput Tomogr, vol.8, issue.1, pp.52-57, 2014.

S. Doddamani, M. J. Grushko, A. N. Makaryus, V. R. Jain, R. Bello et al., Demonstration of left ventricular outflow tract eccentricity by 64-slice multi-detector CT, Int J Cardiovasc Imaging, vol.25, issue.2, pp.175-181, 2009.

Y. Dumont and M. Arsenault, An alternative to standard continuity equation for the calculation of aortic valve area by echocardiography, J Am Soc Echocardiogr, vol.16, issue.12, pp.1309-1315, 2003.

M. Leye, E. Brochet, L. Lepage, C. Cueff, I. Boutron et al., Sizeadjusted left ventricular outflow tract diameter reference values: a safeguard for the evaluation of the severity of aortic stenosis, J Am Soc Echocardiogr, vol.22, issue.5, pp.445-451, 2009.

J. Minners, M. Allgeier, C. Gohlke-baerwolf, R. P. Kienzle, F. J. Neumann et al., Inconsistent grading of aortic valve stenosis by current guidelines: haemodynamic studies in patients with apparently normal left ventricular function, Heart, vol.96, issue.18, pp.1463-1468, 2010.

B. A. Carabello, Clinical practice. Aortic stenosis, N Engl J Med, vol.346, issue.9, pp.677-682, 2002.

H. I. Michelena, E. Margaryan, F. A. Miller, M. Eleid, J. Maalouf et al., Inconsistent echocardiographic grading of aortic stenosis: is the left ventricular outflow tract important?, Heart, vol.99, issue.13, pp.921-931, 2013.

W. A. Zoghbi, Low-gradient "severe" aortic stenosis with normal systolic function: time to refine the guidelines?, Circulation, vol.123, issue.8, pp.838-840, 2011.

M. F. Eleid, R. A. Nishimura, P. Sorajja, and B. A. Borlaug, Systemic hypertension in low-gradient severe aortic stenosis with preserved ejection fraction, Circulation, vol.128, issue.12, pp.1349-1353, 2013.

L. Kadem, J. G. Dumesnil, R. Rieu, L. G. Durand, D. Garcia et al., Impact of systemic hypertension on the assessment of aortic stenosis, Heart, vol.91, issue.3, pp.354-361, 2005.
URL : https://hal.archives-ouvertes.fr/hal-00015469

G. W. Eveborn, H. Schirmer, G. Heggelund, P. Lunde, and K. Rasmussen, The evolving epidemiology of valvular aortic stenosis. the Tromso study, Heart, vol.99, issue.6, pp.396-400, 2013.

G. Barone-rochette, S. Pierard, S. Seldrum, C. De-meester-de-ravenstein, J. Melchior et al., Aortic valve area, stroke volume, left ventricular hypertrophy, remodeling, and fibrosis in aortic stenosis assessed by cardiac magnetic resonance imaging: comparison between high and low gradient and normal and low flow aortic stenosis, Circ Cardiovasc Imaging, vol.6, issue.6, pp.1009-1017, 2013.

R. Carter-storch, J. E. Moller, N. L. Christensen, A. Irmukhadenov, L. M. Rasmussen et al., Postoperative Reverse Remodeling and Symptomatic Improvement in Normal-Flow Low-Gradient Aortic Stenosis After Aortic Valve Replacement, Circ Cardiovasc Imaging, vol.10, issue.12, 2017.

, ANNEXES

H. Baumgartner, Annexe 1 : Recommandations européennes sur les indications de remplacement valvulaire aortique, 2017.

, Eur Heart J, vol.38, issue.36, pp.2739-2791, 2017.

, Annexe 2 : Indice de comorbidité de Charlson

M. E. Charlson, A new method of classifying prognostic comorbidity in longitudinal studies: development and validation, J Chronic Dis, vol.40, issue.5, pp.373-83, 1987.