Calculation of Mitral Valve Area in Mitral Stenosis: Comparison of Continuity Equation and Pressure Half Time With Two-Dimensional Planimetry in Patients With and Without Associated Aortic or Mitral Regurgitation or Atrial Fibrillation
AbstractAccurate measurement of Mitral Valve Area (MVA) is essential to determining the Mitral Stenosis (MS) severity and to achieving the best management strategies for this disease. The goal of the present study is to compare mitral valve area (MVA) measurement by Continuity Equation (CE) and Pressure Half-Time (PHT) methods with that of 2D-Planimetry (PL) in patients with moderate to severe mitral stenosis (MS). This comparison also was performed in subgroups of patients with significant Aortic Insufficiency (AI), Mitral Regurgitation (MR) and Atrial Fibrillation (AF). We studied 70 patients with moderate to severe MS who were referred to echocardiography clinic. MVA was determined by PL, CE and PHT methods. The agreement and correlations between MVA’s obtained from various methods were determined by kappa index, Bland-Altman analysis, and linear regression analysis. The mean values for MVA calculated by CE was 0.81 cm (±0.27) and showed good correlation with those calculated by PL (0.95 cm, ±0.26 ) in whole population (r=0.771, P<0.001) and MR subgroup (r=0.763, P<0.001) and normal sinus rhythm and normal valve subgroups (r=0.858, P<0.001 and r=0.867, P<0.001, respectively). But CE methods didn’t show any correlation in AF and AI subgroups. MVA measured by PHT had a good correlation with that measured by PL in whole population (r=0.770, P<0.001) and also in NSR (r=0.814, P<0.001) and normal valve subgroup (r=0.781, P<0.001). Subgroup with significant AI and those with significant MR showed moderate correlation (r=0.625, P=0.017 and r=0.595, P=0.041, respectively). Bland Altman Analysis showed that CE would estimate MVA smaller in comparison with PL in the whole population and all subgroups and PHT would estimate MVA larger in comparison with PL in the whole population and all subgroups. The mean bias for CE and PHT are 0.14 cm and -0.06 cm respectively. In patients with moderate to severe mitral stenosis, in the absence of concomitant AF, AI or MR, the accuracy of CE or PHT method in measuring MVA is nearly equal. But in the presence of significant AI or MR, PHT method is obviously superior to CE and in the presence of AF neither have sufficient accuracy.
Bonow RO, Carabello BA, Chatterjee K, de Leon AC, Jr., Faxon DP, Freed MD, et al. 2008 focused update incorporated into the ACC/AHA 2006 guidelines 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 (Writing Committee to revise the 1998 guidelines for the management of patients with valvular heart disease). Endorsed by the Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J Am Coll Cardiol 2008;52:e1‐142 .
Henry WL, Griffith JM, Michaelis LL, McIntosh CL, Morrow AG, Epstein SE. Measurement of mitral orifice area in patients with mitral valve disease by real‐time, two‐dimensional echocardiography. Circulation 1975;51:827‐31 .
Oh JK, Hatle LK, Sinak LJ, Seward JB, Tajik AJ. Characteristic Doppler echocardiographic pattern of mitral inflow velocity in severe aortic regurgitation. J Am Coll Cardiol 1989;14:1712‐7 .
Karp K, Teien D, Bjerle P, Eriksson P. Reassessment of valve area determinations in mitral stenosis by the pressure half‐time method: impact of left ventricular stiffness and peak diastolic pressure difference. J Am Coll Cardiol 1989;13:594‐9 .
Iung B, Cormier B, Ducimetiere P, Porte JM, Nallet O, Michel PL, et al. Immediate results of percutaneous mitral commissurotomy. A predictive model on a series of 1514 pa ents. Circulation 1996;94:2124‐30 .
Smith MD, Handshoe R, Handshoe S, Kwan OL, DeMaria AN. Comparative accuracy of two‐ dimensional echocardiography and Doppler pressure half‐time methods in assessing severity of mitral stenosis in patients with and without prior commissurotomy. Circulation 1986;73:100‐7 .
Popovic AD, Stewart WJ. Echocardiographic evaluation of valvular stenosis: the gold standard for the next millennium? Echocardiography 2001;18:59‐63 .
Faletra F, Pezzano A, Jr., Fusco R, Mantero A, Corno R,Crivellaro W, et al. Measurement of mitral valve area in mitral stenosis: four echocardiographic methods compared with direct measurement of anatomic orifices. J Am Coll Cardiol 1996;28:1190‐7
Messika‐Zeitoun D, Iung B, Brochet E, Himbert D, Serfaty JM, Laissy JP, et al. Evaluation of mitral stenosis in 2008. Arch Cardiovasc Dis 2008;101:653‐63 .
Lang RM, Bierig M, Devereux RB, Flachskampf FA, Foster E, Pellikka PA, et al. Recommendations for chamber quantification: a report from the American Society of Echocardiography's Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology. J Am Soc Echocardiogr 2005;18:1440‐63 .
Hatle L, Angelsen B, Tromsdal A. Noninvasive assessment of atrioventricular pressure half‐time by Doppler ultrasound. Circulation 1979;60:1096‐104.
Baumgartner H, Hung J, Bermejo J, Chambers JB, Evangelista A, Griffin BP, et al. Echocardiographic assessment of valve stenosis: EAE/ASE recommendations for clinical practice. J Am Soc Echocardiogr 2009;22:1‐23; quiz 101‐2 .
Iung B, Garbarz E, Michaud P, Helou S, Farah B, Berdah P, et al. Late results of percutaneous mitral commissurotomy in a series of 1024 patients. Analysis of late clinical deteriora on: frequency, anatomic findings, and predictive factors. Circulation 1999;99:3272‐8 .
Nakatani S, Masuyama T, Kodama K, Kitabatake A, Fujii K, Kamada T. Value and limitations of Doppler echocardiography in the quantification of stenotic mitral valve area: comparison of the pressure half‐ me and the continuity equation methods. Circulation 1988;77:78‐85.
Derumeaux G, Lenormand C, Remadi F, Cribier A, Letac B. Contribution of the continuity equation for the assessment of mitral valve area in mitral stenosis. Arch Mal Coeur Vaiss 1991;84:1555‐60.
Chu JW, Levine RA, Chua S, Poh KK, Morris E, Hua L, et al. Assessing mitral valve area and orifice geometry in calcific mitral stenosis: a new solution by real‐time three‐dimensional echocardiography. J Am Soc Echocardiogr 2008;21:1006‐9 .
Palacios IF. What is the gold standard to measure mitral valve area postmitral balloon valvuloplasty? Cathet Cardiovasc Diagn 1994;33:315‐6.
Yamagishi M, Nakatani S, Miyatake K. Quantitative assessment of lumen area stenosis by Doppler echocardiography and application of continuity equation. Echocardiography 1994;11:293‐304.
Messika‐Zeitoun D, Meizels A, Cachier A, Scheuble A,Fondard O, Brochet E, et al. Echocardiographic evaluation of the mitral valve area before and after percutaneous mitral commissurotomy: the pressure half‐time method revisited. J Am Soc Echocardiogr 2005;18:1409- 14 .
Nakatani S, Nagata S, Beppu S, Ishikura F, Tamai J, Yamagishi M, et al. Acute reduction of mitral valve area after percutaneous balloon mitral valvuloplasty: assessment with Doppler continuity equation method. Am Heart J 1991;121:770‐5.
Thomas JD, Wilkins GT, Choong CY, Abascal VM, Palacios IF, Block PC, et al. Inaccuracy of mitral pressure half‐time immediately after percutaneous mitral valvotomy. Dependence on transmitral gradient and left atrial and ventricular compliance. Circulation 988;78:980‐93
Flachskampf FA, Weyman AE, Gillam L, Liu CM, Abascal VM, Thomas JD. Aortic regurgitation shortens Doppler pressure half‐time in mitral stenosis: clinical evidence, in vitro simulation and theoretic analysis. J Am Coll Cardiol 1990;16:396‐404.
Kim HK, Kim YJ, Chang SA, Kim DH, Sohn DW, Oh BH, et al. Impact of cardiac rhythm on mitral valve area calculated by the pressure half time method in patients with moderate or severe mitral stenosis. J Am Soc Echocardiogr 2009;22:42‐7.
Mohan JC, Mukherjee S, Kumar A, Arora R, Patel AR, Pandian NG. Does chronic mitral regurgitation influence Doppler pressure half‐time‐derived calculation of the mitral valve area in patients with mitral stenosis? Am Heart J 2004;148:703‐9.
Tei C, Shah PM, Bae JH, Toyama Y, Horikiri Y, Choue CW, et al. A simple noninvasive measurement of stenotic mitral valve area: an alternative approach using M‐mode and Doppler echocardiography. J Cardiol 1992;22:159‐69