Obesity class does not further stratify outcome in overweight and obese pediatric patients after heart transplantation.

The effect of obesity stratification on pediatric heart transplant outcomes is unknown. The UNOS database was queried for patients ≥2-<18 years listed for heart transplant and stratified by BMI: normal (BMI>5%-≤85 percentile), overweight (BMI=86%-95 percentile), class 1 (BMI=100%-120% of 95 percentile), class 2 (BMI=121%-140% of 95 percentile), and class 3 obesity (BMI>140% of 95 percentile). A total of 5056 individuals were listed for transplant, with 71% normal, 13% overweight, 10% class 1, 4% class 2, and 2% class 3 obesity. Waitlist survival was not different between groups. Post-transplant survival was decreased in overweight and combined obese groups vs normal, with no further difference between overweight and obese classes. Overweight and obese patients had higher listing status and were more likely to have ventilator, inotrope, and mechanical circulatory support at listing. After transplant, there was an association of overweight-obese patients with diabetes and rejection requiring hospitalization. Stricter definition of normal weight reveals overweight-obese status was an independent risk factor for poorer post-transplant survival, without further effect by stratification of weight class. However, because there is no difference in waitlist survival, this study does not allow the selection of absolute weight-based criteria regarding transplant listing and suggests the need to look further for modifiable risk factors post-transplant.