Patient population
From July 2018 to December 2020, a total of 117 consecutive patients with degenerative mitral valve disease and significant MR (grade 2+) in a prospective multicenter study underwent transthoracic and transesophageal echocardiographic assessment and were included in the study.
Twenty-three were excluded for the following reasons: (1) 10 were excluded owning to inadequate echocardiographic image quality for MVN or 3D VCA analysis; (2) 7 were excluded because of with mixed atrial functional mitral regurgitation or presence of mitral annular disjunction; (3) 4 were excluded because of significant concomitant aortic valve disease; (4) 2 was excluded due to having abnormal segmental wall motion. Twenty subjects (ages 67±8.5) undergoing clinically indicated TTE and TEE who have no MR with normal left ventricular (LV) function and mitral apparatus were also examined as controls. The protocol of this study was approved by the institutional review board of Zhongshan Hospital and was conducted in accordance with the Declaration of Helsinki. Written informed consent was obtained at the time of consent for the clinical TEE procedure in all of the patients.