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Spontaneous Resolution of Severe Mitral Regurgitation in a Patient with a Flail Mitral Valve
CASE REPORTS
Spontaneous Resolution of Severe Mitral Regurgitation in a Patient with a Flail Mitral Valve Ihab Asmer, Salim Adawi, MD, Moshe Y. Flugelman, MD, and Avinoam Shiran, MD, Haifa, Israel
Flail mitral valve usually causes severe mitral regurgitation, which may lead to left ventricular dysfunction if left uncorrected. The authors present a case of flail posterior mitral valve leaflet and severe mitral regurgitation in which mitral valve adaptation led to enlargement of the anterior mitral valve leaflet, decrease in mitral regurgitation, and reverse left ventricular remodeling without any need for surgery. (J Am Soc Echocardiogr 2010;23:1335.e1-1335.e4.) Keywords: Mitral regurgitation, Flail mitral valve, Active mitral valve adaptation, Left ventricular remodeling, Resolving mitral regurgitation
CASE PRESENTATION
DISCUSSION
A 39-year-old man presented in 1999 with asymptomatic severe mitral regurgitation (MR) due to a flail mitral valve (MV). His left ventricular (LV) end-diastolic diameter was 5.4 cm at that time. Repeat echocardiography 6 months later, in 2000, showed a moderately dilated left ventricle (LV end-diastolic diameter, 6.3 cm; LV enddiastolic volume, 249 cm3), with normal systolic function (ejection fraction, 67%) and a flail posterior MV leaflet with ruptured chordae to the middle scallop of the posterior leaflet (Figures 1 and 2, Video 1). He had severe MR, with systolic flow reversal in his right pulmonary vein and an effective regurgitant orifice area of 0.84 cm2 (Figures 3 and 4, Video 2). The left atrium was severely enlarged (left atrial volume, 178 cm3), and estimated systolic pulmonary artery pressure was 35 mm Hg. The patient was treated with ramipril 5 mg/d, which was later replaced with candesartan 8 mg/d. During follow-up, MR spontaneously decreased, LV end-diastolic diameter gradually decreased to 5.3 cm, and LV end-diastolic volume decreased to 164 cm3. Echocardiography performed in 2009, 10 years after his presentation, showed a normal-size left ventricle, moderate MR, and normal pulmonary venous flow, with an effective regurgitant orifice area of 0.19 cm2 (Figures 1-4, Videos 3 and 4). Left atrial volume had decreased to 78 cm3, and systolic pulmonary artery pressure had decreased to 21 mm Hg. The most significant findings were that the length of his anterior MV leaflet had increased from 2.5 cm in 2000 to 2.9 cm in 2009 and that his mitral annular diameter had decreased from 4.5 to 4 cm (Figures 1 and 2). This resulted in better occlusion of the MV orifice in systole, with the anterior MV leaflet reaching the posterior MV annulus and compensating for the lack of a functional posterior leaflet in the region of the middle scallop.
Flail MV is usually associated with severe MR, which leads to LV dysfunction, heart failure, and death if not corrected surgically in time.1-3 In this unusual case, the MV partially corrected itself, spontaneously decreasing the degree of MR and leading to reverse LV remodeling, making surgical correction unnecessary. To the best of our knowledge, such a case has never been published before, and we suspect that this is a rare occurrence. The true frequency of spontaneous improvement in MR severity is unknown. Measurements of anterior MV leaflet length are subject to sampling errors due to the possible use of somewhat different imaging planes and the use of different machines and transducers. We have no doubt, however, that the degree of MR significantly reduced over time because of the better closure of the MV orifice by the anterior MV leaflet. Active MV adaptation to LV remodeling, resulting in increased MV leaflet area, has been suggested in patients with functional MR.4 Increased leaflet area can improve coaptation and explain, in part, the variability in functional MR in response to LV remodeling. MV leaflet area has been shown to actively increase in response to increased tethering forces by surgically displaced papillary muscles in sheep.5 The mechanism of this active MV adaptation involves cellular changes suggesting reactivated embryonic developmental pathways. Endothelial-mesenchymal transdifferentiation, mediated by tumor growth factor–b, causes increased collagen deposition and increased leaflet area and thickness. A similar mechanism might have been involved in our case. Increased MV tethering as a result of MR and LV remodeling may have caused the enlargement of the anterior MV leaflet, leading to better occlusion of the MV orifice in systole despite the flail posterior MV leaflet. This in turn led to a decrease in MR severity, reverse LV remodeling, decreased MV annular diameter, and, again, better occlusion of the MV orifice. A beneficial effect of treatment with the angiotensin-converting enzyme inhibitor or angiotensin receptor blocker on LV remodeling cannot be excluded in our case, but such a favorable effect has not been shown in chronic MR without LV dysfunction, and such treatment is not recommended by current guidelines.6,7 Better understanding of the mechanisms leading to active MV adaptation may lead to the development of medical therapy that will
From the Department of Cardiovascular Medicine, Lady Davis Carmel Medical Center, and the Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel. Reprint requests: Avinoam Shiran, MD, Lady Davis Carmel Medical Center, Department of Cardiovascular Medicine, 7 Michal Street, Haifa 34362, Israel (E-mail: [email protected]). 0894-7317/$36.00 Copyright 2010 by the American Society of Echocardiography. doi:10.1016/j.echo.2010.04.021
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1335.e2 Asmer et al
Journal of the American Society of Echocardiography December 2010
Abbreviations
LV = Left ventricular MR = Mitral regurgitation MV = Mitral valve
Figure 1 Transthoracic echocardiography using the apical 4-chamber view. Diastolic MV annular diameter decreased from 4.5 cm in 2000 to 4 cm in 2009. Arrow indicates anterior MV leaflet; arrowhead indicates flail posterior MV leaflet.
Figure 2 Transthoracic apical long-axis view. The length of the unstretched anterior MV leaflet (arrow) in diastole increased from 2.5 cm in 2000 to 2.9 cm in 2009. In 2009, the tip of the anterior MV leaflet reached the posterior MV annulus in systole, leading to better occlusion of the MV orifice.
Journal of the American Society of Echocardiography Volume 23 Number 12
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Figure 3 Color flow Doppler using the apical 4-chamber view (top) and the apical long-axis view (bottom) showing an anteromedially directed MR jet. There was severe MR in 2000 and only moderate MR in 2009. enhance MV remodeling and make the strategy of ‘‘watchful waiting’’ in chronic MR even more appealing.3 REFERENCES 1. Pearson AC, St. Vrain J, Mrosek D, Labovitz AJ. Color Doppler echocardiographic evaluation of patients with a flail mitral leaflet. J Am Coll Cardiol 1990;16:232-9. 2. Ling LH, Enriquez-Sarano M, Seward JB, Tajik AJ, Schaff HV, Bailey KR, et al. Clinical outcome of mitral regurgitation due to flail leaflet. N Engl J Med 1996;335:1417-23. 3. Rosenhek R, Rader F, Klaar U, Gabriel H, Krejc M, Kalbeck D, et al. Outcome of watchful waiting in asymptomatic severe mitral regurgitation. Circulation 2006;113:2238-44. 4. Chaput M, Handschumacher MD, Tournoux F, Hua L, Guerrero JL, Vlahakes GJ, et al. Mitral leaflet adaptation to ventricular remodeling: occurrence and adequacy in patients with functional mitral regurgitation. Circulation 2008;118:845-52.
5. Dal-Bianco JP, Aikawa E, Bischoff J, Guerrero JL, Handschumacher MD, Sullivan S, et al. Active adaptation of the tethered mitral valve: insights into a compensatory mechanism for functional mitral regurgitation. Circulation 2009;120:334-42. 6. 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. Circulation 2008;118: e523-661. 7. Vahanian A, Baumgartner H, Bax J, Butchart E, Dion R, Filippatos G, 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 2007;28:230-68.
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Journal of the American Society of Echocardiography December 2010
Figure 4 (Top) Right pulmonary venous (PV) flow showing systolic flow reversal in 2000 and normal systolic forward flow in 2009. (Bottom) Color flow Doppler with baseline shift showing the flow convergence zone. The effective regurgitant orifice (ERO) was calculated using the proximal isovelocity surface area (PISA) method. The radius (r) of the PISA and the ERO significantly decreased from 2000 to 2009.
Spontaneous Resolution of Severe Mitral Regurgitation in a Patient with a Flail Mitral Valve Ihab Asmer, Salim Adawi, MD, Moshe Y. Flugelman, MD, and Avinoam Shiran, MD, Haifa, Israel
Flail mitral valve usually causes severe mitral regurgitation, which may lead to left ventricular dysfunction if left uncorrected. The authors present a case of flail posterior mitral valve leaflet and severe mitral regurgitation in which mitral valve adaptation led to enlargement of the anterior mitral valve leaflet, decrease in mitral regurgitation, and reverse left ventricular remodeling without any need for surgery. (J Am Soc Echocardiogr 2010;23:1335.e1-1335.e4.) Keywords: Mitral regurgitation, Flail mitral valve, Active mitral valve adaptation, Left ventricular remodeling, Resolving mitral regurgitation
CASE PRESENTATION
DISCUSSION
A 39-year-old man presented in 1999 with asymptomatic severe mitral regurgitation (MR) due to a flail mitral valve (MV). His left ventricular (LV) end-diastolic diameter was 5.4 cm at that time. Repeat echocardiography 6 months later, in 2000, showed a moderately dilated left ventricle (LV end-diastolic diameter, 6.3 cm; LV enddiastolic volume, 249 cm3), with normal systolic function (ejection fraction, 67%) and a flail posterior MV leaflet with ruptured chordae to the middle scallop of the posterior leaflet (Figures 1 and 2, Video 1). He had severe MR, with systolic flow reversal in his right pulmonary vein and an effective regurgitant orifice area of 0.84 cm2 (Figures 3 and 4, Video 2). The left atrium was severely enlarged (left atrial volume, 178 cm3), and estimated systolic pulmonary artery pressure was 35 mm Hg. The patient was treated with ramipril 5 mg/d, which was later replaced with candesartan 8 mg/d. During follow-up, MR spontaneously decreased, LV end-diastolic diameter gradually decreased to 5.3 cm, and LV end-diastolic volume decreased to 164 cm3. Echocardiography performed in 2009, 10 years after his presentation, showed a normal-size left ventricle, moderate MR, and normal pulmonary venous flow, with an effective regurgitant orifice area of 0.19 cm2 (Figures 1-4, Videos 3 and 4). Left atrial volume had decreased to 78 cm3, and systolic pulmonary artery pressure had decreased to 21 mm Hg. The most significant findings were that the length of his anterior MV leaflet had increased from 2.5 cm in 2000 to 2.9 cm in 2009 and that his mitral annular diameter had decreased from 4.5 to 4 cm (Figures 1 and 2). This resulted in better occlusion of the MV orifice in systole, with the anterior MV leaflet reaching the posterior MV annulus and compensating for the lack of a functional posterior leaflet in the region of the middle scallop.
Flail MV is usually associated with severe MR, which leads to LV dysfunction, heart failure, and death if not corrected surgically in time.1-3 In this unusual case, the MV partially corrected itself, spontaneously decreasing the degree of MR and leading to reverse LV remodeling, making surgical correction unnecessary. To the best of our knowledge, such a case has never been published before, and we suspect that this is a rare occurrence. The true frequency of spontaneous improvement in MR severity is unknown. Measurements of anterior MV leaflet length are subject to sampling errors due to the possible use of somewhat different imaging planes and the use of different machines and transducers. We have no doubt, however, that the degree of MR significantly reduced over time because of the better closure of the MV orifice by the anterior MV leaflet. Active MV adaptation to LV remodeling, resulting in increased MV leaflet area, has been suggested in patients with functional MR.4 Increased leaflet area can improve coaptation and explain, in part, the variability in functional MR in response to LV remodeling. MV leaflet area has been shown to actively increase in response to increased tethering forces by surgically displaced papillary muscles in sheep.5 The mechanism of this active MV adaptation involves cellular changes suggesting reactivated embryonic developmental pathways. Endothelial-mesenchymal transdifferentiation, mediated by tumor growth factor–b, causes increased collagen deposition and increased leaflet area and thickness. A similar mechanism might have been involved in our case. Increased MV tethering as a result of MR and LV remodeling may have caused the enlargement of the anterior MV leaflet, leading to better occlusion of the MV orifice in systole despite the flail posterior MV leaflet. This in turn led to a decrease in MR severity, reverse LV remodeling, decreased MV annular diameter, and, again, better occlusion of the MV orifice. A beneficial effect of treatment with the angiotensin-converting enzyme inhibitor or angiotensin receptor blocker on LV remodeling cannot be excluded in our case, but such a favorable effect has not been shown in chronic MR without LV dysfunction, and such treatment is not recommended by current guidelines.6,7 Better understanding of the mechanisms leading to active MV adaptation may lead to the development of medical therapy that will
From the Department of Cardiovascular Medicine, Lady Davis Carmel Medical Center, and the Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel. Reprint requests: Avinoam Shiran, MD, Lady Davis Carmel Medical Center, Department of Cardiovascular Medicine, 7 Michal Street, Haifa 34362, Israel (E-mail: [email protected]). 0894-7317/$36.00 Copyright 2010 by the American Society of Echocardiography. doi:10.1016/j.echo.2010.04.021
1335.e1
1335.e2 Asmer et al
Journal of the American Society of Echocardiography December 2010
Abbreviations
LV = Left ventricular MR = Mitral regurgitation MV = Mitral valve
Figure 1 Transthoracic echocardiography using the apical 4-chamber view. Diastolic MV annular diameter decreased from 4.5 cm in 2000 to 4 cm in 2009. Arrow indicates anterior MV leaflet; arrowhead indicates flail posterior MV leaflet.
Figure 2 Transthoracic apical long-axis view. The length of the unstretched anterior MV leaflet (arrow) in diastole increased from 2.5 cm in 2000 to 2.9 cm in 2009. In 2009, the tip of the anterior MV leaflet reached the posterior MV annulus in systole, leading to better occlusion of the MV orifice.
Journal of the American Society of Echocardiography Volume 23 Number 12
Asmer et al 1335.e3
Figure 3 Color flow Doppler using the apical 4-chamber view (top) and the apical long-axis view (bottom) showing an anteromedially directed MR jet. There was severe MR in 2000 and only moderate MR in 2009. enhance MV remodeling and make the strategy of ‘‘watchful waiting’’ in chronic MR even more appealing.3 REFERENCES 1. Pearson AC, St. Vrain J, Mrosek D, Labovitz AJ. Color Doppler echocardiographic evaluation of patients with a flail mitral leaflet. J Am Coll Cardiol 1990;16:232-9. 2. Ling LH, Enriquez-Sarano M, Seward JB, Tajik AJ, Schaff HV, Bailey KR, et al. Clinical outcome of mitral regurgitation due to flail leaflet. N Engl J Med 1996;335:1417-23. 3. Rosenhek R, Rader F, Klaar U, Gabriel H, Krejc M, Kalbeck D, et al. Outcome of watchful waiting in asymptomatic severe mitral regurgitation. Circulation 2006;113:2238-44. 4. Chaput M, Handschumacher MD, Tournoux F, Hua L, Guerrero JL, Vlahakes GJ, et al. Mitral leaflet adaptation to ventricular remodeling: occurrence and adequacy in patients with functional mitral regurgitation. Circulation 2008;118:845-52.
5. Dal-Bianco JP, Aikawa E, Bischoff J, Guerrero JL, Handschumacher MD, Sullivan S, et al. Active adaptation of the tethered mitral valve: insights into a compensatory mechanism for functional mitral regurgitation. Circulation 2009;120:334-42. 6. 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. Circulation 2008;118: e523-661. 7. Vahanian A, Baumgartner H, Bax J, Butchart E, Dion R, Filippatos G, 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 2007;28:230-68.
1335.e4 Asmer et al
Journal of the American Society of Echocardiography December 2010
Figure 4 (Top) Right pulmonary venous (PV) flow showing systolic flow reversal in 2000 and normal systolic forward flow in 2009. (Bottom) Color flow Doppler with baseline shift showing the flow convergence zone. The effective regurgitant orifice (ERO) was calculated using the proximal isovelocity surface area (PISA) method. The radius (r) of the PISA and the ERO significantly decreased from 2000 to 2009.