[Left Ventricular Structural and Functional Changes in Obese Subjects With Preserved Left Ventricular Ejection Fraction After Bariatric Surgery: Assessment With Cardiac Magnetic Resonance Imaging].

Objective: To investigate the longitudinal changes in left ventricular (LV) structure and function after bariatric surgery in obese individuals and their relationship with preoperative left ventricular ejection fraction (LVEF) by cardiac magnetic resonance (CMR) imaging.

Methods: We prospectively enrolled 75 obese subjects scheduled for laparoscopic sleeve gastrectomy and 46 age and sex-matched healthy controls (the control group). All subjects underwent CMR examination to obtain LV structural parameters, LVEF, and strain parameters. According to their preoperative LVEF, the obese subjects were divided into two obesity groups, including the group of patients with LVEF≥60% (=43) and the group of patients with 50%≤LVEF<60% (=32). LV structural and functional differences between the control group and the two obesity groups were compared. Eventually, 38 obese subjects completed the CMR follow-up at 1 month and 12 months after bariatric surgery. The longitudinal changes in LV structure and function after surgery in the LVEF≥60% (=20) group and the 50%≤LVEF<60% group (=18) were compared.

Results: Before bariatric surgery, the global longitudinal strain was significantly lower in the LVEF≥60% group than that in the control group ([－18.36±1.86]% vs. [－19.50±1.53]%, <0.05). The global radial ([27.70±3.52]% vs. [34.44±4.11]%, <0.05), circumferential ([－17.35±1.46]% vs. [－19.85±1.42]%, <0.05), and longitudinal ([－16.22±1.81]% vs. [－19.50±1.53]%, <0.05) strain in the 50%≤LVEF<60% group was significantly lower than that in the control group. At 12 months after bariatric surgery, the global radial ([32.52±7.84]% vs. [30.92±4.27]%, >0.05), circumferential ([－19.02±2.42]% vs. [－18.63±1.49]%, >0.05), and longitudinal ([－18.18±2.06]% vs. [－17.78±1.66]%, >0.05) strain in the LVEF≥60% group showed no significant difference compared with the baseline findings. In the 50%≤LVEF<60% group, the global radial ([32.73±5.86]% vs. [26.83±4.85]%, <0.05) and circumferential ([－19.10±2.00]% vs. [－16.91±2.09]%, <0.05) strain was significantly higher than that before surgery.

Conclusion: LV remodeling is reversed after bariatric surgery in obese subjects, and the longitudinal changes in LV structure and function vary with the preoperative LVEF.