1. Nishimura RA, Otto CM, Bonow RO, et al. 2017 AHA/ACC focused update of the 2014 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 clinical practice guidelines. Circulation. 2017;135:e1169-e 1195.
2. Vahanian A, Alfieri O, Andreotti F, et al. Guidelines on the management of valvular heart disease (version 2012). Eur Heart J. 2012;33:2451–96.
3. Chang B-C, Youn Y-N, Ha J-W, Lim S-H, Hong Y-S, Chung N. Long-term clinical results of mitral valvuloplasty using flexible and rigid rings: a prospective and randomized study. J Thorac Cardiovasc Surg. 2007;133:995–1003.
4. Hu X, Zhao Q. Systematic evaluation of the flexible and rigid annuloplasty ring after mitral valve repair for mitral regurgitation. Eur J Cardiothorac Surg. 2011;40:480–7.
5. Yokote J, Araki Y, Saito S, Hasegawa H, Usui A. Effect of an artificial ring on mitral valve function. Nagoya J Med Sci. 2019;81:207–15.