O1101: Improved Cardiovascular Function Following Bariatric Surgery in Youths with Severe Obesity

Background: Cardiovascular (CV) disease associated with obesity causes significant morbidity and mortality and is seen as early as adolescence. The American Academy of Pediatrics recognized the importance of surgical intervention as an effective and safe option for weight loss in severely obese (SO) pediatric patients. However, there remains significant resistance to surgical options. The impact of bariatric surgery on the CV function in adolescents is not well elucidated but is critical to understand how surgery may alter the trajectory of patients’ CV health. In this study, we perform comprehensive assessment of cardiovascular system in the adolescent patients with SO before and after bariatric intervention.

Methods: Youths (12-18 years old) being considered for bariatric surgery were prospectively enrolled. Demographic data, cardiac MRI, SphygmoCor and flow-mediated dilation (FMD) were obtained preoperatively (n=9) and at least 6 months after having laparoscopic sleeve gastrectomy (n=4). Outcomes of myocardial volume, function, edema (T2 mapping), mass (LVMi), ventricular-vascular coupling ratio (LVVCR), and measures of central and peripheral compliance were collected.

Results: Mean age of enrolled patients was 15.8+2.3 years. They represented a racially diverse population, and females represented 44%. At baseline, none of the patients had been diagnosed with overt cardiac disease or diabetes. There was evidence of increased ascending and descending aortic stiffness compared to normative values (decreased aortic distensibility and compliance, and increased augmentation pressure) (Table 1). Left ventricular cardiac output (LVCOi) was positively correlated to BMI (r=0.89, p=0.002). Mean T2 mapping value compared to normative data in this age group was elevated which reflects increased edema in the myocardium. This, in combination with elevated CRP, was in alignment with the reported role of inflammation in the development of cardiac dysfunction in obese patients.
Postoperatively, patients had significant reduction in left ventricular mass and LVCOi (Table 2). Central vasculature trended towards decreased stiffness (increased aortic distensibility/compliance and decreased central augmented pressure) without a significant change in peripheral vasculature compliance as measured by flow mediated dilation (FMD). The decrease in LVMi showed significant correlation to the increase in aortic distensibility/compliance (r =-0.95, p=0.05). The mean T2 map was persistently high.

Conclusion: Though limited by small sample size, this pilot study suggests that adolescents with SO without overt CV disease have early CV maladaptation, and that bariatric surgery may be effective in reversing some these changes. Our patients had increased aortic stiffness at baseline without change during the post-operative period, although there was decrease in LVMi and decrease in LVCOi. Persistent elevation of LVMi and LVCOi decreases myocardial efficiency, and myocardial edema may contribute to obesity-related cardiomyopathy. Bariatric surgery may play a significant role in preventing the development of this disease. Longer follow-up period is needed to understand CV changes following bariatric surgery.