Abstract 13473: The Adverse Impact of Diabetes Mellitus on Ventricular Remodeling in Patients with Severe Aortic Stenosis
Background: Patients with diabetes mellitus (DM) exhibit increased left ventricular (LV) mass and reduced ventricular function. However, this relationship has not been studied in patients with aortic stenosis (AS)--a disease process that causes LV hypertrophy and dysfunction through a distinct mechanism. Animal models of pressure overload suggest that insulin resistance induces more LV hypertrophy and chamber dilation and impairs ventricular function.
Hypothesis: DM adversely impacts how the LV remodels in response to pressure overload in AS and is associated with reduced LV function.
Methods: Ninety-five patients with severe AS [mean age 82 years, 51% female, aortic valve area (AVA) 0.59 cm2, ejection fraction (EF) 50%, 47% with DM] had echocardiograms analyzed (GE Vivid 7 with EchoPac™ 2D speckle tracking). Three apical views were used to measure peak longitudinal systolic strain in 18 segments, which were then averaged. Relative wall thickness (RWT = 2 × posterior wall thickness / LV end-diastolic dimension) and LV mass (area-length) were also measured.
Results: In univariable analyses, diabetics were more likely to be younger, male, have an increased LV mass index (140 ± 29 g/m2 vs. 121 ± 30 g/m2), larger systolic and diastolic cavity dimensions (LVESD, LVEDD), and have lower RWT, EF, and longitudinal systolic strain. AVA and systolic BP were similar. In multivariable analyses adjusting for age, sex, systolic BP, AVA, BSA, and coronary disease, DM was an independent predictor of increased LV mass (β=34 gm; p=0.004), LVEDD (β=0.37 cm; p=0.02), LVESD (β=0.56 cm; p=0.01), but not RWT (p=0.6). Among diabetics, insulin use was not associated with increased LV mass (p=0.6). After adjusting for age, gender, systolic BP, AVA, BSA, coronary disease, and LV mass, DM was not associated with EF (p=0.09) or LV systolic strain (p=0.1), whereas LV mass was a strong predictor of a reduced EF and LV systolic strain (p<0.001 for both).
Conclusions: DM has an additive adverse effect on hypertrophic remodeling--increased LV mass and larger cavity dimensions--in patients with AS beyond known factors of pressure overload. Although diabetics have reduced LV function, the mechanism by which this occurs appears to be related to its influence on LV remodeling.
- © 2010 by American Heart Association, Inc.