Patient-Specific Analysis Of Pre-Surgical Leaflet Deformations To Predict Outcomes Of Surgical Repair For Ischemic Mitral Regurgitation

Introduction: Ischemic mitral regurgitation (IMR) is a highly prevalent disorder, and current methods of repair have suboptimal rates of failure. Accounting for patient-specific variations in the pre-surgical deformation patterns of the mitral valve (MV) may allow for better prediction of post-surgical outcomes. Methods: Real-time 3D echocardiographic images of the MV were segmented to create geometric representations for 20 patients (10 with and 10 without IMR recurrence) immediately pre- and post-annuloplasty repair as well as for 5 healthy MVs. To build correspondence between the open and closed valve geometries in each state, we morphed the open state geometry to the closed state shape within a finite element framework. Metrics including directional in-plane strains, leaflet area, and orifice dimensions were then computed and compared between the valves with and without recurrent IMR. Results: We found that MVs with IMR had significantly lower magnitudes of compressive circumferential strain in the posterior leaflet and higher radial strains across the whole MV than MVs without IMR (Figure). Patients who would later exhibit MR recurrence were found to have significantly higher circumferential leaflet strain in the anterior commissure prior to surgery than those without recurrence (p = 0.0228). The recurrent MVs also had significantly larger leaflet areas and annuli than the non-recurrent MVs, and their annuli contracted less. Conclusions: Key characteristics of IMR including increased downward leaflet tethering, annular dilation, and reduced ability to contract were most pronounced in MVs with recurrent IMR, suggesting that valves with recurrence may be in a more progressed disease state pre-surgically or may have a different manifestation of the myocardial infarct. Such factors could be used to predict post-surgical IMR recurrence and improve surgical planning.