Validity of the distance between mitral leaflets coaptation point and annular plane in differentiation between ischemic and dilated cardiomyopathy

Background: Identification of patients with ischemic cardiomyopathy (ICM) from those with idiopathic dilated cardiomyopathy (DCM) is important therapeutically and prognostically. Objective: To assess the validity of the distance between the mitral leaflets coaptation point and the mitral annular plane (CPMA) at low dose dobutamine stress echocardiography (DSE) for differentiation between ICM and DCM. Patients and methods: Echocardiographic indices and CPMA were measured at baseline and during dobutamine infusion for 50 patients who were presenting with heart failure and reduced ejection fraction (EF). Patients were divided into two groups depending on coronary angiographic findings, group I (ICM with significant coronary artery disease) and group II (DCM with normal coronary arteries).Results: Compared with baseline values, the CPMA at low dose DSE decreased significantly in ICM patients (11.8 ± 2.2 vs 8 ± 1.2. mm, P< 0.01) while it showed non-significant change in patients with DCM (11.66 ± 2.3 vs 11.99 ± 2.22. mm, P> 0.05). At low dose DSE ICM group showed a high statistically significant negative correlation between CPMA and both EF (r= -0.749, P< 0.0001) and viability index (r= -0.782, P< 0.0001) and significant positive correlation with WMSI (r= 0.79, P< 0.0001). Receiver operating characteristic (ROC) CPMA cut-off value ≤ 9 mm at low dose DSE, had sensitivity of 76.92%, specificity of 85.71% in detecting patients with ICM. Conclusion: Measurement of CPMA at low dose DSE might help in identifying patients with ICM from those with DCM. © 2011.