Early Changes in Left and Right Ventricular Function in Obese Patients after Bariatric Surgery

Background: Severe obesity causes hemodynamic changes in the circulatory system, which leads to the development of heart failure with either preserved or reduced ejection fraction. Weight loss achieved through bariatric surgery is likely to possibly reverse many of hemodynamic and structural abnormalities caused by obesity. Methods: Detailed echocardiographic parameters assessing left and right ventricular function in severely obese patients undergoing bariatric surgery were analyzed. The following parameters were compared in the examinations performed before surgery and 3 and 6 months after surgery: left ventricular ejection fraction (LVEF), left ventricle (LV) and right ventricle (RV) global longitudinal strain (GLS and GSRV) with right ventricular free wall strain (FWSRV), peak early (e’) and late (a’) diastolic annular velocities (lateral and septal) with calculation of E/e’ ratios, left atrium volume index (LAVI), left atrial strain (LAS) including LAS conduit ( LAS-cd) and LAS tricuspid regurgitation velocity (TRV), tricuspid annular plane systolic excursion (TAPSE), maximum systolic velocity of the lateral part of the tricuspid annulus-s’ and accelerated pulmonary time (AcT). Results: Forty consecutive obese patients undergoing bariatric surgery from December 2022 till June 2023 were enrolled to the study. Finally 39 patients were included. The study population consisted of 76% women with mean BMI of 40.3 (SD 5.6) and mean age of 42.4 (SD 11.9). BMI after 3 months was 35,3 kg/m2, after 6 months was 31.2 kg/m2 (SD 5.1). At 3- and 6-month follow-up after bariatric surgery there was a reduction in left ventricular mass (109.7 vs. 99.1 vs. 87.4 kg/m2; p<0.001), LVEDV (47.1 vs. 30.0 vs. 43.7; p<0.001) and SV (29.7 vs. 24.3 vs. 26.3; p=0.05). Simultaneously an improvement in GLS (-14.38 vs. -16.79 vs. -18.01) and an increase in LAS parameters (reservoir : 22.5 vs. 28.0 vs. 31.1; p<0.001 and conduit: -12.8 vs. -16.5 vs. -19.6) were observed. Comparison of right ventricular parameters before and after bariatric surgery showed improvement in GSRV (-15.9 vs. -18.8 vs. -18.38%; p=0.005), FWS (-18.38 vs. -19.70 vs. -19.50; p=0.042) and reduction in TRV (1.84 vs. 1.67 vs. 1.46±0.52; p=0.01). Conclusions: Weight loss contributes to rapid improvement in left and right ventricular function. Some changes of echocardiographic parameters: LVEDV, LAS-r, LAS-cd, GSRV and TAPSE correlate with the degree of weight loss. New echocardiographic parameters earlier detect subclinical hemodynamic changes associated with obesity and weight loss after bariatric surgery.