Abstract 21327: Successful Undersized Restrictive Annuloplasty for Chronic Mitral Regurgitation with Advanced Cardiomyopathy Does Not Induce Functional Mitral Stenosis
Introduction: It remains controversial whether an undersized restrictive mitral annuloplasty (URMA) for chronic mitral regurgitation, based on the concept of mitral annulus restriction, may cause functional mitral stenosis. Herein, we evaluated hemodynamic changes in left ventricular (LV) function and mitral valve performance after URMA.
Methods: We studied 119 patients with reduced ejection fraction (<40%) who underwent URMA using a Carpentier-Edwards Physio ring for chronic mitral regurgitation between 2003 and 2009. Echocardiographic studies were performed to evaluate mitral valve geometry, systolic pulmonary artery pressure (PAP), and right ventricular end-diastolic dimension (RVDd) at baseline and 12 months after surgery. LV function and hemodynamic measurements was calculated by right heart catheterization at discharge.
Results: Clinical symptoms as shown by NYHA class improved from 3.2±0.5 to 1.5±0.6 (p<0.01). The mean size of the annuloplasty ring implanted during URMA was 24.8±1.0 mm. The URMA procedure provided a significant improvement in mitral regurgitation, accompanied with restored mitral valve geometry at discharge as compared to the baseline measurement (leaflet coaptation; 8.2±2.5 vs. 4.1±1.5 mm, p<0.01, tenting height; 4.2±1.8 vs. 7.9±2.4 mm, p<0.01). Postoperative cardiac catheterization also revealed significant improvements in LV function, pulmonary artery pressure, and cardiac index, with a catheter-derived transmitral pressure gradient of 3.6±3.2 mmHg, suggesting no evidence of functional mitral stenosis. Postoperative echocardiographic examinations showed continuous improvements in right ventricular function at 12 months after surgery as compared to the baseline measurements (systolic PAP; 32±9 vs. 45±15 mm, p<0.01, RVDd; 25±5 vs. 30±7 mm, p<0.05).
Conclusion: URMA for chronic MR resulted in significant improvements in LV function and mitral valve performance in a majority of patients without causing significant mitral stenosis.
- © 2010 by American Heart Association, Inc.