Cardiovascular recovery following bariatric surgery in extremely obese adolescents: Preliminary results using Cardiac Magnetic Resonance (CMR) Imaging

Purpose: Baseline cardiovascular characteristics and longitudinal changes following weight loss surgery (WLS) in adolescents are not well defined. Recent data suggest that the use of transthoracic echocardiography (TTE) for preoperative cardiac assessment may provide suboptimal imaging fidelity secondary to excessive upper body adiposity. High fidelity imaging using cardiac magnetic resonance (CMR) is an extremely useful diagnostic tool. We report the use of CMR in a cohort of extremely obese adolescents undergoing WLS. Methods: A retrospective analysis of adolescent WLS patients at a single institution was conducted. Data collection included mean age, sex, body mass index (BMI), and CMR measurements of left ventricular (LV) mass, LV end-diastolic volume (LVEDV), ejection fraction (EF), and myocardial perfusion reserve index (MPRI). Comparison of CMR results to normative data derived from lean subjects was performed. Results: Ten subjects (9 female), with a mean age and BMI of 17.4 ± 1.9 years and 50.33 ± 10.21 kg/m² respectively, were studied. When compared to age, gender, and height matched normal weight (NW) controls, the obese (OB) subjects had evidence of increased LV mass (122 ± 25 g vs. 101 ± 10 g, OB vs. NW respectively, p < 0.05), and increased LVEDV (156 ± 25 mL vs. 109 ± 9 mL, p < 0.05), with an average EF of 61.5% ± 5% (range 52% to 67% vs. 71% to 74% expected EF for males and females, respectively, p = 0.003). In addition, 60% of the OB subjects (6/10) demonstrated adenosine-induced sub-endocardial ischemia at baseline, the majority of whom underwent WLS (n = 5) resulting in complete normalization of ischemia in 60% (3/5) and partial improvement in 40% (2/5). A reduction in mean LV mass (range 2 to 12 g) following WLS was observed. Conclusion: Extreme adolescent obesity is associated with significant cardiovascular abnormalities that include LV hypertrophy (i.e. increased LV mass) and LV dilatation. These findings, considered to be well-recognized cardiovascular disease risk factors in adults, were shown to be reversible after WLS in the small group of subjects studied here. Additional large-scale investigations designed to examine obesity-related cardiovascular disease in severely obese adolescents are required.