Surgery for Asymptomatic Mitral Regurgitation
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《新英格兰医药杂志》
To the Editor: In their study of determinants of the outcome of asymptomatic mitral regurgitation, Enriquez-Sarano et al. (March 3 issue)1 concluded that patients who have an effective regurgitant orifice of at least 40 mm2 should be considered for surgery promptly. We have some concern about this conclusion, which we believe to be overstated.
In the study, 80 percent of patients had mitral-valve prolapse as the cause of mitral regurgitation, but the anatomical characteristics of the mitral valve on echocardiography were not reported. A previous study showed that patients with mitral-leaflet thickening (5 mm) had a risk of complications, including sudden death, infective endocarditis, and cerebral embolic events, that was 15 times that in patients without such thickening.2 In another study, the length of mitral-valve leaflets was greater in hearts from patients who died suddenly than in hearts from patients in whom mitral-valve prolapse was an incidental finding at autopsy.3 In addition, patients with flail leaflets, an extreme form of mitral-valve prolapse, have high mortality and morbidity.4 All these factors should be taken into account, together with the quantitation of mitral regurgitation, in deciding whether or not to recommend surgery.
In addition, it should be kept in mind that mitral regurgitation in patients with mitral-valve prolapse can be dynamic and evanescent.5 Thus, quantitative assessment of mitral regurgitation should be repeated during longitudinal follow-up to confirm the initial data.
Haoyi Zheng, M.D.
Yale–New Haven Hospital
New Haven, CT 06510
haoyi.zheng@yale.edu
Huichun Zhan, M.D.
Long Island Jewish Hospital
New Hyde Park, NY 11040
References
Enriquez-Sarano M, Avierinos J-F, Messika-Zeitoun D, et al. Quantitative determinants of the outcome of asymptomatic mitral regurgitation. N Engl J Med 2005;352:875-883.
Nishimura RA, McGoon MD, Shub C, Miller FA Jr, Ilstrup DM, Tajik AJ. Echocardiographically documented mitral-valve prolapse: long-term follow-up of 237 patients. N Engl J Med 1985;313:1305-1309.
Farb A, Tang AL, Atkinson JB, McCarthy WF, Virmani R. Comparison of cardiac findings in patients with mitral valve prolapse who die suddenly to those who have congestive heart failure from mitral regurgitation and to those with fatal noncardiac conditions. Am J Cardiol 1992;70:234-239.
Ling LH, Enriquez-Sarano M, Seward JB, et al. Clinical outcome of mitral regurgitation due to flail leaflet. N Engl J Med 1996;335:1417-1423.
Hayek E, Gring CN, Griffin BP. Mitral valve prolapse. Lancet 2005;365:507-518.
The authors reply: Valve tissue characteristics were not analyzed in our study of mitral regurgitation, but our studies have not found such characteristics to have a significant influence on the clinical course when adjustment is made for the severity of mitral regurgitation. In previous large community studies of mitral-valve prolapse, valve thickening predicted the risk of stroke,1 but not mortality or the incidence of cardiac events.2 Sudden death is very uncommon in young patients with mitral-valve prolapse who have mild mitral regurgitation or none, irrespective of the characteristics of the valve tissue.2
Mitral regurgitation is the most important determinant of mortality in patients with mitral-valve prolapse,2 and mortality and morbidity in patients with flail mitral leaflets are a consequence of severe regurgitation.3 Furthermore, although mitral regurgitation is dynamic with acute loading changes, under normal conditions it is neither evanescent nor markedly variable.4 In our study, approximately 90 percent of patients who underwent surgery had mitral repair, resulting in the correction of mitral regurgitation but with the persistence of residual myxomatous tissue. The improved clinical outcomes in these patients illustrate the importance of the severity of regurgitation, rather than tissue characteristics, in determining the prognosis.
Maurice Enriquez-Sarano, M.D.
Hartzell V. Schaff, M.D.
A. Jamil Tajik, M.D.
Mayo Clinic
Rochester, MN 55905
sarano.maurice@mayo.edu
References
Avierinos JF, Brown RD, Foley DA, et al. Cerebral ischemic events after diagnosis of mitral valve prolapse: a community-based study of incidence and predictive factors. Stroke 2003;34:1339-1344.
Avierinos JF, Gersh BJ, Melton LJ III, et al. Natural history of asymptomatic mitral valve prolapse in the community. Circulation 2002;106:1355-1361.
Ling LH, Enriquez-Sarano M, Seward JB, et al. Clinical outcome of mitral regurgitation due to flail leaflet. N Engl J Med 1996;335:1417-1423.
Dujardin KS, Enriquez-Sarano M, Bailey KR, Seward JB, Tajik AJ. Effect of losartan on degree of mitral regurgitation quantified by echocardiography. Am J Cardiol 2001;87:570-576.
In the study, 80 percent of patients had mitral-valve prolapse as the cause of mitral regurgitation, but the anatomical characteristics of the mitral valve on echocardiography were not reported. A previous study showed that patients with mitral-leaflet thickening (5 mm) had a risk of complications, including sudden death, infective endocarditis, and cerebral embolic events, that was 15 times that in patients without such thickening.2 In another study, the length of mitral-valve leaflets was greater in hearts from patients who died suddenly than in hearts from patients in whom mitral-valve prolapse was an incidental finding at autopsy.3 In addition, patients with flail leaflets, an extreme form of mitral-valve prolapse, have high mortality and morbidity.4 All these factors should be taken into account, together with the quantitation of mitral regurgitation, in deciding whether or not to recommend surgery.
In addition, it should be kept in mind that mitral regurgitation in patients with mitral-valve prolapse can be dynamic and evanescent.5 Thus, quantitative assessment of mitral regurgitation should be repeated during longitudinal follow-up to confirm the initial data.
Haoyi Zheng, M.D.
Yale–New Haven Hospital
New Haven, CT 06510
haoyi.zheng@yale.edu
Huichun Zhan, M.D.
Long Island Jewish Hospital
New Hyde Park, NY 11040
References
Enriquez-Sarano M, Avierinos J-F, Messika-Zeitoun D, et al. Quantitative determinants of the outcome of asymptomatic mitral regurgitation. N Engl J Med 2005;352:875-883.
Nishimura RA, McGoon MD, Shub C, Miller FA Jr, Ilstrup DM, Tajik AJ. Echocardiographically documented mitral-valve prolapse: long-term follow-up of 237 patients. N Engl J Med 1985;313:1305-1309.
Farb A, Tang AL, Atkinson JB, McCarthy WF, Virmani R. Comparison of cardiac findings in patients with mitral valve prolapse who die suddenly to those who have congestive heart failure from mitral regurgitation and to those with fatal noncardiac conditions. Am J Cardiol 1992;70:234-239.
Ling LH, Enriquez-Sarano M, Seward JB, et al. Clinical outcome of mitral regurgitation due to flail leaflet. N Engl J Med 1996;335:1417-1423.
Hayek E, Gring CN, Griffin BP. Mitral valve prolapse. Lancet 2005;365:507-518.
The authors reply: Valve tissue characteristics were not analyzed in our study of mitral regurgitation, but our studies have not found such characteristics to have a significant influence on the clinical course when adjustment is made for the severity of mitral regurgitation. In previous large community studies of mitral-valve prolapse, valve thickening predicted the risk of stroke,1 but not mortality or the incidence of cardiac events.2 Sudden death is very uncommon in young patients with mitral-valve prolapse who have mild mitral regurgitation or none, irrespective of the characteristics of the valve tissue.2
Mitral regurgitation is the most important determinant of mortality in patients with mitral-valve prolapse,2 and mortality and morbidity in patients with flail mitral leaflets are a consequence of severe regurgitation.3 Furthermore, although mitral regurgitation is dynamic with acute loading changes, under normal conditions it is neither evanescent nor markedly variable.4 In our study, approximately 90 percent of patients who underwent surgery had mitral repair, resulting in the correction of mitral regurgitation but with the persistence of residual myxomatous tissue. The improved clinical outcomes in these patients illustrate the importance of the severity of regurgitation, rather than tissue characteristics, in determining the prognosis.
Maurice Enriquez-Sarano, M.D.
Hartzell V. Schaff, M.D.
A. Jamil Tajik, M.D.
Mayo Clinic
Rochester, MN 55905
sarano.maurice@mayo.edu
References
Avierinos JF, Brown RD, Foley DA, et al. Cerebral ischemic events after diagnosis of mitral valve prolapse: a community-based study of incidence and predictive factors. Stroke 2003;34:1339-1344.
Avierinos JF, Gersh BJ, Melton LJ III, et al. Natural history of asymptomatic mitral valve prolapse in the community. Circulation 2002;106:1355-1361.
Ling LH, Enriquez-Sarano M, Seward JB, et al. Clinical outcome of mitral regurgitation due to flail leaflet. N Engl J Med 1996;335:1417-1423.
Dujardin KS, Enriquez-Sarano M, Bailey KR, Seward JB, Tajik AJ. Effect of losartan on degree of mitral regurgitation quantified by echocardiography. Am J Cardiol 2001;87:570-576.