Mitral regurgitation (MR) is a common heart valve disease. Mitral regurgitation is when incomplete closure of the mitral valve during the contraction of the left ventricle causes a part of the blood flow from the left atrium to the left ventricle to go back to the left atrium, resulting in a series of cardiac pathological changes and clinical symptoms, and in severe cases, heart failure.
MR is a common heart disease in China [1, 3]. According to a survey conducted by Fuwai Hospital of the National Center for Cardiovascular Diseases, the incidence of mild MR is as high as 23% and that of moderate and severe MR is 2.2% among people aged over 65 [2]. The incidence of all-cause mortality in asymptomatic severe MR patients reached (22±3)% [4] within 5 years, while the annual mortality rate in patients with severe heart failure reached 34% [5].
The current treatments of mitral regurgitation mainly include medication, surgery and interventional therapy. Clinical studies have shown that medication can only improve symptoms and cannot prolong survival or operative time [6]. In the United States, 49% of MR patients cannot undergo surgery due to high risks of cardiac insufficiency, complications and advanced age [7]. In China, more than 40,000 mitral valve surgeries are performed every year, but most MR patients are not effectively treated[8].
The rapid development of transcatheter mitral valve intervention techniques in the recent decade has brought new hope to MR patients. MR interventional techniques can be divided into two categories: transcatheter mitral valve repair and transcatheter mitral valve replacement. At present, the transcatheter edge-to-edge repair technique is the most mature in the transcatheter mitral valve repair. More than 100,000 repairs have been carried out and it is recommended by the guidelines [9]. At the same time, percutaneous valve replacement devices have been developed as an alternative and more effective option for reducing MR.
Transcatheter mitral valve edge-to-edge repair changes the treatment of primary and secondary mitral regurgitation [1] and provides a less invasive interventional approach than surgery. At the same time, more and more clinical evidence has been obtained to support the use of transcatheter mitral valve edge-to-edge repair [2-5], and it is being gradually applied in more complex mitral valve lesions and clinical situations [1].
As a minimally invasive interventional procedure for mitral regurgitation, transcatheter mitral valve replacement overcomes the limitations of the current edge-to-edge repair technique, and it may completely correct regurgitation and prevent the long-term development of mitral regurgitation [1]. Although transcatheter mitral valve replacement has developed more slowly than TAVI, several clinical trials have been conducted since 2012 to explore the feasibility and safety of such devices [2], showing that the procedure, especially through the interatrial septum pathway, could lead to faster postoperative recovery, shorter hospital stay, and better long-term outcomes for patients [1].
References
[1] Li J, Pan W, Yin Y, Cheng L, Shu X. Prevalence and correlates of mitral regurgitation in the current era: an echocardiography study of a Chinese patient population. Acta Cardiol. 2016 Feb;71(1):55–60.
[2] Nkomo VT,Gardin JM,Skelton TN, Gottdiener JS, Scott CG, Enriquez-Sarano M.Burden of valvular heart diseases: a population-based study.Lancet Lond Engl.2006 Sep;368(9540):1005–11.
[3] Hu P, Liu X-B, Liang J, Zhu Q-F, Pu C-X, Tang M-Y, et al.A hospital-based survey of patients with severe valvular heart disease in China.Int J Cardiol.2017 Mar;231:244–7.
[4] Enriquez-Sarano M, Avierinos J-F, Messika-Zeitoun D, Detaint D, Capps M, Nkomo V, et al. Quantitative determinants of the outcome of asymptomatic mitral regurgitation.N Engl J Med.2005 Mar;352(9):875–83.
[5] 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 Nov;335(19):1417–23.
[6] Carabello BA.The current therapy for mitral regurgitation.J Am Coll Cardiol.2008 Jul;52(5):319–26.
[7] Head SJ, van Leeuwen WJ, Van Mieghem NM, Kappetein AP.Surgical or transcatheter mitral valve intervention: complex disease requires complex decisions.EuroIntervention J Eur Collab Work Group Interv Cardiol Eur Soc Cardiol.2014 Feb;9(10):1133–5.
[8] 赵举, 黑飞龙. 2015中国心脏外科和体外循环数据白皮书. 中国体外循环杂志. 2016;14(3):130–2.
[9] 结构心脏病年度报告2021.
References
[1] Flint, N., Price, M., Little, S., Mackensen,G., Wunderlich, N.,Makar, M.,&Siegel, R.(2021). State of the Art: Transcatheter Edge-to-Edge Repair for Complex Mitral Regurgitation. Journal Of The American Society Of Echocardiography,34(10),1025-1037. https://doi.org/10.1016/j.echo.2021.03.240
[2] Alperi,A.,Granada,J.,Bernier,M.,Dagenais,F.,&Rodés-Cabau,J. (2021). Current Status and Future Prospects of Transcatheter Mitral Valve Replacement.Journal Of The American College Of Cardiology,77(24), 3058-3078.https://doi.org/10.1016/j.jacc.2021.04.051.
[3] Stone,G.,Lindenfeld,J.,Abraham, W.,Kar,S., Lim, D., & Mishell,J.et al.(2018).Transcatheter Mitral-Valve Repair in Patients with Heart Failure.New England Journal Of Medicine,379(24), 2307-2318. https://doi.org/10.1056/nejmoa1806640
[4] Nishimura, R.,Otto, C., Bonow, R.,Carabello, B., Erwin, J., & Fleisher, L. et al.(2017). 2017 AHA/ACC Focused Update of the 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease. Journal Of The American College Of Cardiology,70(2), 252-289. https://doi.org/10.1016/j.jacc.2017.03.011
[5] Feldman, T.,Foster,E.,Glower,D., Kar, S.,Rinaldi, M.,& Fail, P.et al. (2011).Percutaneous Repair or Surgery for Mitral Regurgitation.New England Journal Of Medicine,364(15),1395-1406. https://doi.org/10.1056/nejmoa1009355
References
[1] Alperi, A., Granada, J., Bernier, M., Dagenais, F., & Rodés-Cabau, J. (2021). Current Status and Future Prospects of Transcatheter Mitral Valve Replacement. Journal Of The American College Of Cardiology, 77(24), 3058-3078. https://doi.org/10.1016/j.jacc.2021.04.051
[2] Dahle, G. (2020). Current Devices in TMVI and Their Limitations: Focus on Tendyne. Frontiers In Cardiovascular Medicine, 7. https://doi.org/10.3389/fcvm.2020.592909
