Annular geometry in patients with chronic ischemic mitral regurgitation: three-dimensional magnetic resonance imaging study.
BACKGROUND
Although animal studies showed that annular remodeling may be related to the pathogenesis of chronic ischemic mitral regurgitation (CIMR), little was known in humans. A better understanding of the precise 3D geometry of the mitral valvular-ventricular complex in CIMR is needed to devise a better surgical technique. The purpose of the study was to elucidate mitral annular geometry in patients with CIMR using cardiac MRI.


RESULTS
Thirty-eight patients with previous inferior or posterior myocardial infarction were studied. With the 3D reconstruction of the mitral annulus and subvalvular apparatus from a series of longitudinal cine MRIs, end-systolic mitral annulus dimensions and 3D geometry were calculated. Patients were grouped by mitral regurgitation grade using echocardiography (> or =2+, n=15 versus < or =1+, n=23). Both septal-lateral and commissure-commissure mitral annular diameters were significantly greater in CIMR(+) patients (35+/-5 versus 30+/-4 mm, P=0.005; 46+/-6 versus 39+/-4 mm, P<0.001, respectively). The length of the fibrous annulus was significantly larger in CIMR(+) patients (28+/-3 versus 24+/-3 mm; P<0.001). The height of the annular "saddle horn" above a best-fit plane was lower in CIMR(+) patients (4.2+/-1.2 versus 6.0+/-1.8 mm; P=0.002), and the annular height to commissural width ratio was significantly lower in CIMR(+) patients (12+/-3 versus 21+/-5%; P<0.001).


CONCLUSIONS
Patients with CIMR had greater septal-lateral and commissure-commissure mitral annular dimension, larger intertrigonal distance, and flattened saddle shape of mitral annulus. These associated geometric alterations may be important in the pathogenesis of CIMR.
Kaji
Shuichiro
S
Division of Cardiology, Department of Cardiovascular Surgery, Kobe General Hospital, 4-6, Minatojima-nakamachi, Kobe, 650-0046, Japan. skaji@kcgh.gr.jp
Nasu
Michihiro
M
Yamamuro
Atsushi
A
Tanabe
Kazuaki
K
Nagai
Kunihiko
K
Tani
Tomoko
T
Tamita
Koichi
K
Shiratori
Kenichi
K
Kinoshita
Makoto
M
Senda
Michio
M
Okada
Yukikatsu
Y
Morioka
Shigefumi
S
D000328:Adult; D000368:Aged; D000886:Anthropometry / Q000379:methods; D018618:Echocardiography, Doppler, Color; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000473:pathology*; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology*; D009203:Myocardial Infarction / Q000150:complications*; D010210:Papillary Muscles / Q000473:pathology; D011446:Prospective Studies; D012720:Severity of Illness Index; D013318:Stroke Volume; D016896:Treatment Outcome