Ischemic mitral regurgitation: impact of the left ventricle and mitral valve in patients with left ventricular systolic dysfunction.
BACKGROUND
Mitral regurgitation (MR) is a common complication of ischemic heart disease, and its presence portends adverse outcomes. As the exact mechanisms of ischemic MR are not well defined, we characterized left ventricular global geometry, regional function, and regional myocardial scarring, in addition to mitral valve apparatus geometry, using magnetic resonance imaging (MRI) of ischemic heart disease patients with left ventricular dysfunction and varying degrees of ischemic MR.


METHODS
Sixty patients with varying degrees of MR (none, mild, moderate, and severe) determined by echocardiography and referred for MRI assessment of ischemic heart disease were included. Left ventricular geometric, functional, and scar measurements in addition to mitral valve geometric measurements were evaluated.


RESULTS
Clinical characteristics found to be significant predictors of degree of MR included severity of coronary artery disease (p < 0.05), completeness of myocardial perfusion (p < 0.005), and average systolic blood pressure (p < 0.05). Mitral systolic tenting area (p < 0.0001) in a statistical model with scarring of the anterior-lateral region (p < 0.05) proved to be the most powerful predictor of MR severity (r2 = 0.31). Mitral annular dilatation in the anterior-posterior direction (p < 0.0001) and diminished LV systolic function (p < 0.005) were important determinants of mitral systolic tenting area (r2 = 0.57).


CONCLUSIONS
Mitral tenting in combination with regional left ventricular myocardial scarring are important mechanisms to the development of ischemic MR. Surgical annuloplasty addresses mitral tenting, but has little impact on the effect of regional scarring. Moderate-to-severe ischemic MR develops in patients with regional scarring of the anterior-lateral and inferior-posterior regions, and new surgical developments should take this into account.
Srichai
Monvadi B
MB
Department of Radiology, Cleveland Clinic Foundation, Cleveland, Ohio, USA.
Grimm
Richard A
RA
Stillman
Arthur E
AE
Gillinov
A Marc
AM
Rodriguez
L Leonardo
LL
Lieber
Michael L
ML
Lara
Abigail
A
Weaver
Joan A
JA
McCarthy
Patrick M
PM
White
Richard D
RD
D000368:Aged; D002921:Cicatrix; D003324:Coronary Artery Disease / Q000150:complications; D004452:Echocardiography; D005260:Female; D006352:Heart Ventricles; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve; D008944:Mitral Valve Insufficiency / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D012189:Retrospective Studies; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*