SUBJECTS AND METHODS: Twenty-three patients with IMR, 10 with dilated cardiomyopathy with MR (DCM-MR) and 7 control subjects were enrolled. Hemodynamic indices, severity of MR, geometric parameters of mitral apparatus and myocardial viability were evaluated in all patients, and re-evaluated in the IMR patients 6 months after the revascularization.

RESULTS: The mitral tenting area (TAA) (334.1±11.7 mm2 vs. 222.9±23.0 mm2, p=0.16) and the sum of the tenting angles (TA) (72.9±2.9degreevs. 51.5±1.1degree p<0.001) at the mid-systolic phase were increased in the IMR compared to the DCM-MR patients. In the IMR patients, the MR severity was positively correlated with the sum of the tethering lengths (r=0.522, p=0.011), LVESV (r=0.551, p=0.006), TAA (r=0.613, p=0.002) and TA (r=0.713, p<0.001). Of the 10 patients with viable myocardium, who had been revascularized without surgical repair of the mitral apparatus, the MR severity was decreased (28.3±0.4% vs. 16.5±.6%, p=0.009) in 7 patients, with decreases in the sum of the tethering distances (51.2±3.9 mm vs. 40.2±.1 mm, p=0.034), tenting area (299.2±3.8 mm2 vs. 215.0±3.6 mm2, p=0.036) and sum of the tenting angles (72.9±2.9degreevs. 56.2±4.8degree, p=0.015) 6 months after the revascularization.

CONCLUSION: IMR was related with the geometric change in the mitral apparatus. Cardiac MRI can be an effective tool for evaluating these geometric changes and when formulating a treatment plan.