Mechanism of persistent ischemic mitral regurgitation after annuloplasty: importance of augmented posterior mitral leaflet tethering.
BACKGROUND
We hypothesized that surgical annuloplasty for ischemic mitral regurgitation (MR) that displaces the posterior annulus anteriorly can potentially augment posterior leaflet (PML) tethering, leading to persistent MR. Relationships between leaflet configurations and persistent ischemic MR after the annuloplasty were investigated.


RESULTS
In 31 patients with surgical annuloplasty for ischemic MR and 20 controls, posterior and apical displacement of the leaflet coaptation, the anterior leaflet (AML) and PML tethering angles relative to the line connecting annuli, coaptation length (CL), and the MR grade were quantified before and early after surgery in echocardiographic left ventricular long-axis views. Six of the 31 patients showed persistent MR despite annuloplasty. Compared with patients without persistent MR, those with MR showed no improvement in the left ventricular ejection fraction and systolic volume, similar reduction in the annular area, significant increase in posterior displacement of the coaptation (P<0.01), no improvement in AML tethering, greater worsening in PML tethering (P<0.01), and no increase in the CL. All tethering variables were significantly correlated with both preoperative and postoperative MR in univariate analysis, and reduced CL was the primary independent determinant of both preoperative and postoperative MR. Although increased AML tethering was the primary determinant of the preoperative CL (r2=0.46, P<0.0001), increased PML tethering was the primary determinant afterward (r2=0.60, P<0.0001).


CONCLUSIONS
Although tethering of both leaflets is the major determinant of ischemic MR before surgical annuloplasty, both leaflets tethering but with predominant and augmented PML tethering is related to persistent ischemic MR after the annnuloplasty.
Zhu
Fang
F
Department of Cardiovascular, Respiratory and Metabolic Medicine, Graduate School of Medicine, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima City, 890-8520, Japan.
Otsuji
Yutaka
Y
Yotsumoto
Goichi
G
Yuasa
Toshinori
T
Ueno
Takayuki
T
Yu
Bo
B
Koriyama
Chihaya
C
Hamasaki
Shuichi
S
Biro
Sadatoshi
S
Kisanuki
Akira
A
Minagoe
Shinichi
S
Levine
Robert A
RA
Sakata
Ryuzo
R
Tei
Chuwa
C
D000368:Aged; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D017202:Myocardial Ischemia / Q000150:complications*; D010210:Papillary Muscles / Q000473:pathology / Q000503:physiopathology; D012008:Recurrence; D012720:Severity of Illness Index; D013318:Stroke Volume