Impact of severe obesity and weight loss on systolic left ventricular function and morphology: Assessment by two-dimensional speckle-tracking echocardiography

Background: Obesity is associated with an increased risk of heart failure. Little is known about the impact of dietary changes on the cardiac sequelae in obese patients. The aim of the study was to examine systolic left ventricular function and the effect of diet-induced weight loss in patients with severe obesity by transthoracic two-speckle-tracking echocardiography (STE) with LV strain imaging.

Method: Twenty-one obese subjects underwent a 12-week low calorie (800 kcal/day) fasting phase of a formula diet (Optifast®, Nestlé Health Science, Frankfurt, Germany). Transthoracic two-dimensional speckle-tracking echocardiography was performed to obtain systolic left ventricular strain before and after weight loss. Total body composition and fat content was measured by dual energy X-ray absorptiometry (DXA) at baseline and after 12 weeks.

Results: Body mass index decreased significantly from 38.6 ± 6.2 to 31.5 ± 5.3 kg/m² and the total percentage fat loss was 19%. Weight reduction was associated with a reduction in blood pressure and heart rate. Left ventricular longitudinal global peak systolic strain was in the lower normal range (-18.7 ± 3.2%) before weight loss and was unchanged (-18.8 ± 2.4%) after 12 weeks on diet with substantial weight loss. Also, no significant change in global radial strain after weight loss was noted (41.1 ± 22.0 versus 43.9 ± 23.3, p = 0.09). Left atrial and ventricular dimensions were in normal range before fasting and remained unchanged after weight loss.

Conclusion: Obesity was associated with normal systolic left ventricular function. A 12-week low calorie diet with successful weight loss can reduce blood pressure and heart rate. Systolic left ventricular function and morphology were not affected by rapid weight reduction.