Abstract 4368187: Mitral Valve Ellipticity and Functional Recovery After M-TEER: AP/LM Ratio as a Marker of Symptomatic Improvement

Abstract

Background: Mitral regurgitation (MR) remains a significant cause of morbidity, and MitraClip transcatheter edge-to-edge repair (M-TEER) is an effective treatment for symptomatic severe MR. While MR severity and left atrial pressures are traditionally used to guide response, although predictors of clinical response remain unclear. Mitral annular geometry, particularly the anteroposterior to lateromedial (AP/LM) diameter ratio which may reflect MV remodeling. The relationship between changes in AP/LM ratio post-M-TEER and symptomatic improvement is not well defined. Methods: We retrospectively analyzed 107 patients who underwent M-TEER at our center, of whom 74 had echocardiographic follow-up at 1 month and 1 year. Primary outcomes included changes in AP diameter and AP/LM ratio over time. NYHA improvement was defined as any reduction in class at 1 or 12 months. Patients were stratified by NYHA response, and group differences were assessed using descriptive statistics and t-tests. Results: Decrease in AP/LM ratio from 1.071 to 1.050 at one month in the NYHA improvement group (n=42) compared to an increase in AP/LM ratio in the non-improvement group (n=32) from 1.028 to 1.072. By one year, the improved group exhibited a continued decline to 1.032, whereas the non-improved group rose further to 1.092 (Figure 1). Although changes in absolute AP diameter were minimal across both groups (Table 1), a consistent trend toward normalization of the mitral annular shape was highlighted by a lower or stable AP/LM ratio as observed in the improved group. Conclusion: A decrease in the AP/LM ratio following M-TEER may be associated with NYHA class improvement. Although differences were not statistically significant, the improved group consistently demonstrated favorable trends in AP/LM ratio, suggesting that annular geometric remodeling may contribute to symptomatic improvement. A lower AP/LM ratio reflects a more elliptical mitral valve geometry, which may help reduce regurgitation by promoting more effective leaflet coaptation. Larger studies are warranted to validate the AP/LM ratio as a potential marker of procedural success.