Abstract 15985: Mechanistic Determinants of Improved Functional Capacity in Heart Failure Patients Undergoing Percutaneous Mitral Annuloplasty for Functional Mitral Regurgitation
Introduction: Functional mitral regurgitation (FMR) frequently accompanies heart failure (HF) and is associated with increased morbidity and mortality. Recently, percutaneous techniques have been developed to address FMR in HF patients, demonstrating beneficial effects on FMR, quality of life and left ventricular function. The precise mechanism that accounts for the improvement in functional capacity is however unclear. Here we sought to investigate the relative contributions of reverse ventricular remodelling and reduced FMR in the favorable effect of percutaneous mitral annuloplasty using a coronary sinus based approach.
Methods and Results: We retrospectively evaluated the determinants of changes in functional capacity 6 months after enrolment in patients participating in the TITAN trial of the Carillon Mitral Annuloplasty Device (Cardiac Dimensions). The cohort consisted of 27 implanted patients and 10 ‘controls’ in whom the device was not implanted. Left ventricular dimensions, mitral regurgitation severity, quality of life (KCCQ), 6-min walk time (6MWT) and treadmill exercise double product (ExDP) were measured at baseline and 6 month follow-up. Patients undergoing percutaneous mitral annuloplasty had significant improvements (presented as delta values) in quality of life (23±3 vs 4±5, p<0.01), 6MWT (96±34 vs -12±40m, p=0.05), ExDP (704±757 vs -3833±713 mmHg.min-1, p<0.05), LVEDD (-0.14±0.07cm vs 0.12±0.06, p<0.05) together with reduced FMR (MR grade: -1.07±0.15 vs -0.11±0.11, p=0.001). Six month changes in 6MWT, KCCQ and ExDP were not correlated with the extent of reverse left ventricular remodelling. In contrast, the 6 month alterations in 6MWT (r=-0.33, p<0.05), KCCQ (r=-0.32, p=0.07) and ExDP (-0.50, p<0.01) were inversely related to the extent of FMR reduction.
Conclusion: Improvements in functional capacity after device-based reduction in FMR are related to the extent of FMR diminution. This observation suggests that percutaneous FMR reduction devices act by modulating the dynamic nature of FMR during activity.
- © 2012 by American Heart Association, Inc.