Associations between Bodyweight and Clinical Outcome in Patients Post-Fontan Procedure: A Systematic Review

Background: Patients born with a single ventricle circulation commonly experience growth failure in early life, which is associated with adverse outcomes in infancy. However, associations between bodyweight or weight trajectory and clinical outcome post-Fontan procedure are yet to be determined. Methods: On the 1st of July 2021, a systematic review was performed in MEDLINE, EMBASE, the Cochrane Library, and Scopus of studies of patients with clinical outcome data post-Fontan procedure and association with bodyweight. Quality of studies was evaluated by Newcastle–Ottawa scale for cohort studies and Joanna Briggs Institute tool for cross-sectional studies. Results: Of 527 studies that underwent title and abstract screening, 15 were selected for final review. An increased risk of adverse post-Fontan outcomes was found for low weight patients, consistent with findings in infants. Whilst there is some evidence to suggest increased mortality in overweight adult patients, studies are conflicting as to whether overweight status is associated with increased heart failure. Increased BMI is associated with diminished exercise capacity and deceased physiological functioning. Negative weight trajectory is associated with adverse outcomes in the peri-Fontan period, whereas a positive weight trajectory is associated with increased Fontan failure in adulthood. Abnormal BMI (high or low) is associated with increased heart failure and poorer performance in quality-of-life scores. Conclusions: Bodyweight is a modifiable risk factor for poor clinical outcome in patients with a single ventricle circulation. Recognizing associations between bodyweight and Fontan pathophysiology may help to define patient-centered exercise and diet interventions that minimize patient morbidity and mortality.