Abstract 18364: Impact of Obesity on Left Atrial Enlargement: Does LV Geometry and Hypertrophy Matter?
Obesity has been identified as a strong independent determinant of left atrial (LA) enlargement (LAE). However, studies examining the independent association of obesity with LAE in relation to LV mass and LV geometric patterns are lacking. We evaluated 47,749 patients [29,181 non-obese (BMI <30; age: 63.4 ± 16.2 yrs) and 18,568 obese (BMI ≥ 30; age: 58.6 ± 13.7 yrs)] with preserved EF to determine the significance of LV mass and geometric patterns in assessing the impact of obesity on the LAE, determined using mean + 2SD of LA volume indexed to height (LAVi). Obese patients had significantly higher LAVi (36.9 ± 13.9 vs. 31.4 ± 13.6, p<0.0001), LAE (6% vs. 4%, p<0.0001), LVMi (45.3 ± 15.0 vs. 37.1 ± 13.1, p<0.0001), and LV hypertrophy (28% vs. 11%, p<0.0001) than non-obese. Patients with LAE had higher BMI (31.5 ± 7.9 vs. 29.3 ± 6.9, p<0.0001), obesity (51% vs. 38%, p<0.0001), LVMi (53.6 ± 18.9 vs. 39.6 ± 13.8, p<0.0001), and LV hypertrophy (51% vs. 16%, p<0.0001). Patients with LV hypertrophy had higher LAVi compared to patients without LV hypertrophy but showed no difference in LAVi by obesity status (Figure 1). In multivariate analysis, to remove this potential confounding impact of LVMi (obesity status*LVMi interaction, p=0.001), the association of obese vs. non-obese with LAE was assessed separately in patients with normal or increased LVMi as well as by different LV geometric patterns (Figure 2). A significant independent association of obesity with LAE was present only in patients without LV hypertrophy. In conclusion, although obesity, LAE, and LV geometry are closely linked, LV geometry significantly impacts the association between obesity and LAE.
- © 2010 by American Heart Association, Inc.