Abstract
BACKGROUND: Mitral annular plane systolic excursion (MAPSE) is an M-mode derived echocardiographic marker of left ventricular longitudinal function, the aim of this study is to evaluate the value of MAPSE in assessment of contractile reserve in patients with ischemic cardiomyopathy before cardiac revascularization. METHODS: The study included 50 patients with ischemic cardiomyopathy with ejection fraction (EF) ≤35%, the patients presented to echocardiography laboratory for dobutamine stress echocardiography (DSE) to assess viability and contractile reserve before revascularization, patients with primary valvular disease, and those with significant mitral annular calcifications were excluded from the study. A low dose DSE was done to all patients using standardized incremental infusions of 5, 10, and 20 μg/kg/min and the following parameters were measured at both baseline and peak dose, (EF, wall motion score index(WMSI) and MAPSE). Contractile reserve was measured as the difference between the low dose and baseline values of the EF and WMSI. RESULTS: The study included 50 patients aged 55.08±7.15 years, 94% were males, the DSE protocol was complete in all patients without serious side effects. A total of eight hundred segments were analyzed, at baseline 65% were dysfunctional including 31.2% hypokinetic, 28.8% were akinetic, and 5% were dyskinetic. At low dose study 70% of the dysfunctional myocardium showed viability, EF increased significantly from 30.84±4.56 to 42.24±8.15%, p <0.001, the WMSI reduced significantly from 1.92±0.33 to 1.47±0.39, and MAPSE increased significantly from 1.02±0.23 to 1.30±0.30mm. MAPSE showed a significant positive correlation with EF at both baseline and low dose study (r=0.283, p=0.046 & r=0.348, p=0.013) respectively and a significant negative correlation with WMSI at both baseline and low dose study (r=-0.3, p=0.034 & r=-0.409, p=0.003), respectively. By ROC curve analysis we found that Δ MAPSE ≥2mm can predict contractile reserve at Δ EF >10% (AUC=0.6, sensitivity 67.86, specificity 59.09), and Δ MAPSE ≥1.8mm can predict contractile reserve at ΔWMSI ≤0.20 (AUC=0.61, sensitivity 65.5, specificity 75.6). CONCLUSIONS: MAPSE is a rapid simple quantitative echocardiographic method that can asses contractile reserve in patients with ischemic cardiomyopathy before cardiac revascularization.