Abstract 10647: Importance of Volumetric Analysis as an Indicator of Left Ventricular Remodeling in Patients with Chronic Severe Mitral Regurgitation
Background: The timing of surgery for patients with severe chronic mitral regurgitation (MR) remains controversial. Despite current guideline recommendations, postoperative left ventricular (LV) dysfunction is not uncommon.
Objective: Using cardiac magnetic resonance imaging (MRI), we comprehensively evaluated the hypothesis that in MR patients, occult severe LV remodeling is not reflected by standard echocardiographic measurements at the base of the heart.
Methods: 94 patients (54±11 yrs, 38% female) with chronic degenerative isolated MR underwent MRI with tissue tagging and 3D geometry and strain analysis at base, mid and apex.
Results: In 50 control subjects (44±14 yrs, 53% female), there was a linear relationship between LV end-systolic volume (ESV) and LV ES dimension (D), while in 94 MR patients this relationship was exponential. For the LVESD range of 35-40mm, LVESV was significantly higher in MR vs. control (P=0.024) and this variance was attributed to increased spherical remodeling in the LV mid and apex (P=0.0002). 41 patients had surgery for chronic severe MR (35 repair, 6 replacement) and LVEF decreased from 63±7 to 54±11 % (P<0.0001) 12 months after surgery. Postoperatively, maximum shortening was significantly below normal at LV base, mid, and apex (P<0.0001). 3D analysis showed that despite normalized LV end-diastolic volume and LV mass to end-diastolic volume ratio, there was persistent mid to apex spherical remodeling (P <0.05 vs. control) at ES, contributing to postoperative decrease in LVEF and high LVESV index which did not differ from that pre-surgery (38±19 vs. 39±14 ml/m2, P=0.47).
Conclusions: Significant adverse LVES remodeling occurs distal to the tips of the papillary muscles and contributes to the decrease in LVEF following surgery for chronic severe MR. Taken together, LVESD alone did not reflect the extent of LV remodeling suggesting that a volumetric analysis may be a preferred indicator of progressive LV remodeling in isolated MR.
- © 2011 by American Heart Association, Inc.