Abstract 15304: Age and Gender-Related Remodeling Influences Left Ventricular Torsion Assessed by Tagged Cardiac Magnetic Resonance in Asymptomatic Individuals: the Multi-Ethnic Study of Atherosclerosis
Background Age-related alterations of LV structure and function are not completely understood. LV torsion has been reported to reduce myocardial energy consumption, oxygen demand and transmural fiber stress gradients, resulting in a more efficient LV contraction. The aim of the present study was to examine the association between LV torsion and age or gender, and to evaluate how torsion relates to LV remodeling in a healthy population.
Methods Age-related differences in LV structure, strain and torsion were assessed by tagged MRI in 1480 participants without clinically apparent cardiovascular disease in the Multi-Ethnic Study of Atherosclerosis (MESA). Torsion was assessed as the instantaneous difference between apical and basal rotation, adjusted for slice distance. Associations of age and gender with MRI remodeling measures were examined using multivariable linear regression models with covariate adjustments for ethnicity, gender, heart rate, BMI, smoking, systolic BP, cholesterol, fasting glucose, GFR, and the use of medication to control hypertension, lipidemia or diabetes.
Results In multivariable linear regression models, decreased LV end systolic, end diastolic and stroke volumes were associated with age (-3.2, -7.4 and -4.2 ml/decade respectively, all p<0.001) and women (-13.8, -24.3 and -10.6 ml vs. men, respectively, all p<0.001). Circumferential shortening was also significantly reduced with age and in women (0.3%/ decade, and 0.4% vs. men, both p<0.001). However, torsion increased with age and more intensely in women (0.2 degree/cm/decade, and 0.6 degree/cm vs. men, both p<0.001).
Conclusions LV torsion increases with age and more prominently in women. Age is associated with a significant reduction of stroke volume, mainly due to reduced end diastolic LV volume and circumferential myocardial shortening. LV torsion, however, increased with age, and may represent a crucial compensatory mechanism to maintain an adequate cardiac output.
- © 2011 by American Heart Association, Inc.