Abstract 15049: Impact of Cardiac Resynchronization Therapy on Mitral Valve Apparatus Geometry and Clinical Outcomes in Patients With Secondary Mitral Regurgitation
Background: Cardiac resynchronization therapy (CRT) may improve secondary mitral regurgitation (MR) in patients with cardiomyopathy. We evaluated the changes in mitral valve (MV) and left ventricular (LV) geometry after CRT, and its impact on clinical outcomes.
Methods: Between 2009 and 2012, 229 CRT implants were performed, of which 71 had ≥ mild MR at baseline and serial echocardiography performed, with no subsequent MV intervention. The pre-CRT and follow-up echocardiograms of these patients were reviewed for: 1) LV remodeling indices; 2) measurements of MV and LV geometry; and, 3) semi-quantitative grading of MR.
Results: The mean age and QRS interval were 67 ± 15 years and 160 ± 29 ms. The cardiomyopathy was ischemic in 37 (52%), and the most common LV lead implantation site was the posterolateral coronary sinus branch (49%). At a mean echocardiographic follow-up of 4.0 ± 1.9 years, there were significant improvements in LV ejection fraction (25% vs. 32%; p<0.001) and end-systolic volume index (87 vs. 77 cc/m2; p=0.02), MR grade (1.9 vs. 1.5; p=0.001), MR vena contracta (0.37 vs. 0.29 mm; p=0.001), MV tenting area (2.3 vs. 2.0 cm2; p=0.03), MV anterior leaflet tethering angle (47 vs. 43 degrees; p=0.03), and end-systolic interpapillary muscle distance (20 vs. 18 mm; p=0.01). CRT was associated with reductions in moderate-to-severe MR (27% vs. 15%; p=0.04) and New York Heart Association functional class III/IV symptoms (83% vs. 41%; p<0.001). Multivariable analysis revealed the pre-CRT end-systolic interpapillary muscle distance as an independent predictor of moderate or greater MR at follow-up (OR 1.19, 95% CI 1.02-1.38; p=0.02), with a cutoff of ≥ 22mm having a sensitivity and specificity of 50% and 84% (p=0.02). At 5 years post-CRT implantation, the cumulative survival and freedom from LV assist device or cardiac transplantation was 61%, and was significantly worse for patients with New York Heart Association functional class III/IV symptoms (39% vs. 92%; p<0.001) or moderate or greater MR (64% vs. 80%; p=0.04), versus those without.
Conclusions: CRT results in favorable effects on MV and LV geometry and decreases the prevalence of moderate-to-severe MR and heart failure symptoms, which are associated with improved outcomes at mid-term follow-up.
Author Disclosures: C.G. Mihos: None. E. Yucel: None. R. Capoulade: None. M.P. Orencole: None. G.A. Upadhyay: None. O. Santana: None. J.P. Singh: None. M.H. Picard: None.
- © 2016 by American Heart Association, Inc.