Left Ventricular Morphology and Function in Normotensive, Metabolically Healthy Obese Individuals without Fatty Liver Disease.

BACKGROUND: Obesity is one of the major risk factors for the development of heart failure (HF), although the exact underlying mechanism remains unclear. In the clinical setting, assessing the impact of obesity on the cardiovascular system is difficult due to comorbidities. OBJECTIVES: The purpose of this study was to evaluate an independent influence of obesity on the left ventricular (LV) morphology and function. To eliminate hemodynamic and metabolic confounders, we performed an echocardiographic evaluation of severely obese but normotensive and metabolically healthy patients without fatty liver disease. METHODS: The patients were retrospectively selected from the cohort of 180 consecutive obese patients systematically evaluated with transthoracic echocardiography before bariatric surgery. Finally, 25 obese subjects, predominantly females, were evaluated with transthoracic echocardiography. Inclusion criteria were defined as absence of diabetes, hypertension, and hyperlipidemia, no use of medications and no hepatic steatosis on liver biopsy. They were matched with a control group of healthy subjects with normal body mass index. RESULTS: In obese patients, LV hypertrophy (LVH) (expressed as LV mass indexed for height in meters2.7) was significantly more frequent in the obese group (48 vs. 0%, p < 0.001). LV longitudinal systolic function measured by mitral annular systolic velocity was significantly lower in the obese group (S' 8.5 vs. 9.7 cm/s, p = 0.002). All studied indices of the LV diastolic function (E/A, mean E' and E/E' ratio) were impaired in obese subjects, even after adjustment for systolic blood pressure and heart rate (E/A 1.31 vs. 1.64, p < 0.001, E' mean 11 vs. 14.8 cm/s, p < 0.001, E/E' 7.5 vs. 6.4, p = 0.002 for obese vs. controls, respectively). CONCLUSIONS: LVH is significantly more common, and LV diastolic and longitudinal systolic function is significantly impaired in young, metabolically healthy, normotensive, severely obese individuals without fatty liver disease when compared to age and sex-matched lean subjects. These abnormalities may represent the independent effect of the obesity on the heart, which may contribute to the development the obesity-related HF in later life.

The Influence of Surgical Weight Reduction on Left Atrial Strain.

BACKGROUND: Obesity increases and surgical weight reduction decreases the risk of atrial fibrillation (AF) and heart failure (HF). We hypothesized that surgically induced weight loss may favorably affect left atrial (LA) mechanical function measured by longitudinal strain, which has recently emerged as an independent imaging biomarker of increased AF and HF risk. METHODS: We retrospectively evaluated echocardiograms performed before and 12.2 ± 2.2 months after bariatric surgery in 65 patients with severe obesity (mean age 39 [36; 47] years, 72% of females) with no known cardiac disease or arrhythmia. The LA mechanical function was measured by the longitudinal strain using the semi-automatic speckle tracking method. RESULTS: After surgery, body mass index decreased from 43.72 ± 4.34 to 30.04 ± 4.33 kg/m2. We observed a significant improvement in all components of the LA strain. LA reservoir strain (LASR) and LA conduit strain (LASCD) significantly increased (35.7% vs 38.95%, p = 0.0005 and - 19.6% vs - 24.4%, p < 0.0001) and LA contraction strain (LASCT) significantly decreased (- 16% vs - 14%, p = 0.0075). There was a significant correlation between an increase in LASR and LASCD and the improvement in parameters of left ventricular diastolic and longitudinal systolic function (increase in E' and MAPSE). Another significant correlation was identified between the decrease in LASCT and an improvement in LA function (decrease in A'). CONCLUSIONS: The left atrial mechanical function improves after bariatric surgery. It is partially explained by the beneficial effect of weight reduction on the left ventricular diastolic and longitudinal systolic function. This effect may contribute to decreased risk of AF and HF after bariatric surgery.