Abstract 3552: Assessing Mitral Tetrahedron by Real Time 3-dimensional Echocardiography Predicts the Functional Mitral Regurgitation after Myocardial Infarction
Introduction: FMR (functional mitral regurgitation) after MI, providing incremental prognostic information, results from multifactorial processes of the left ventricular remodeling. A mitral tetrahedron defined by the medial and lateral papillary muscle roots and the anterior and posterior mitral annulus have been characterized with MRI to be the geometric surrogate for FMR. However, this ventricular surrogate has not been compared with valvular determinants in predicting FMR.
Hypothesis: Quantitative analysis of the mitral apparatus and the ventricular surrogate provides information about geometric alteration during the process of FMR.
Methods: Patients received 2D and real-time 3D echocardiography 3 months after primary angioplasty for MI. A FMR with an effective regurgitant orifice ≥ 20 mm2 was considered significant.
Results: 40 patients (age 51±8 years, 36 males) were enrolled. Among 16 patients having significant FMR, the LVEDV was larger (p=0.04) and LVEF was less (p=0.04). The FMR was correlated with larger mitral valve area (p=0.008), increased tenting area (p<0.001) and height (p<0.001), as well as lengthened interpapillary distance (p=0.004). A stepwise regression showed only the mitral tenting area (cutoff, 0.79 cm2) and interpapillary distance (19 mm) independently predicting FMR with a sensitivity of 0.69 and a specificity of 0.88. Subgroup analysis revealed that only the interpapillary distance independently determined FMR for anterior MI, and for inferolateral MI, only the mitral tenting area.
Conclusions. The LV remodeling and FMR developed responding to locations of MI and should be considered for an appropriate intervention strategy.