Effect of obesity on left ventricular mass and systolic function in patients with asymptomatic aortic stenosis (a Simvastatin Ezetimibe in Aortic Stenosis [SEAS] substudy)

Abstract

Obesity and hypertension are associated with left ventricular (LV) hypertrophy. Whether an increased body mass index (BMI) affects LV hypertrophy in patients with asymptomatic aortic stenosis independent of hypertension is not known. We used the clinical blood pressure, BMI, and echocardiographic findings recorded at baseline of 1,703 patients with asymptomatic aortic stenosis (AS) participating in the Simvastatin Ezetimibe in Aortic Stenosis (SEAS) study. The patient population was divided into 3 BMI classes: normal BMI, 18.5 to 24.9 kg/m(2); overweight, BMI 25.0 to 29.9 kg/m(2); and obese, BMI > or =30.0 kg/m(2). For the total study population, the average blood pressure was 145/82 +/- 20/10 mm Hg, age 67 +/- 10 years, BMI 26.9 +/- 4.3 kg/m(2), and peak transaortic velocity 3.1 +/- 0.5 m/s. The prevalence of hypertension increased with increasing BMI class (43% vs 51% and 63%, p <0.01). The LV mass and prevalence of LV hypertrophy increased with an increasing BMI (22% in normal, 38% in overweight, and 54% in obese patients). The LV ejection fraction and stress-corrected mid-wall fractional shortening decreased (p <0.01 vs normal-weight group). On multiple logistic regression analysis, the presence of LV hypertrophy was associated with a greater BMI (odds ratio 1.15, 95% confidence interval 1.12 to 1.18), independent of a history of hypertension, the severity of AS, older age, systolic blood pressure, and lower LV ejection fraction (all p <0.05). Valve regurgitation and gender had no independent association with the presence of LV hypertrophy. In conclusion, a greater BMI was associated with the presence of LV hypertrophy in patients with asymptomatic AS, independent of AS severity and the presence of hypertension.