Too fat or too thin? Body habitus assessment in children listed for heart transplant and impact on outcome

Background: Body habitus assessment (BHA), be it wasted or obese, is a useful marker of nutritional status and overall medical condition. Wasting and obesity pre-heart transplant adversely affects outcomes in adults. The utility of BHA as a prognostic factor in children post-transplant is unknown. Methods: Weight and height at listing and standard growth charts were used to determine the ideal body weight (%IBW) and percentiles for body mass index for age (BMI%) and weight-for-length (W:L%). Wasting was defined as <90%IBW and/or <= 5th percentile for BMI% or W:L%. Obesity was defined as >120%IBW and/or >= 95th percentile BMI% or W:L%. Outcomes of cohorts based on these criteria were compared. Results: From June 1990 to December 2006, 180 children, aged 5.81 +/- 6 years, were listed for transplant. Wasting occurred in 66 (37%) and, obesity in 22 (12%) children, without differences between diagnoses of cardiomyopathy or congenital heart disease. %IBW was a prognostic factor for survival post-transplant on multivariate analysis: obese patients had a hazard ratio (HR) of 3.82 (95% confidence interval [CI] 1.81 to 8.06) compared with normal BHA (p < 0.001). Wasting had a survival advantage compared with normal BHA (HR 0.51, 95% Cl 0.27 to 0.94, P = 0.032). There were no significant differences between cohorts in incidence of infections, first-year rejections or graft vasculopathy. Conclusions: Abnormal BHA at listing was a prognostic factor for survival post-transplant. Obese children had increased mortality, but wasting did not adversely affect post-transplant survival in our population. Body habitus assessment may risk-stratify children at listing, potentially providing a complex target for intervention.