Post-Cardiac Transplant Changes in Body Mass Index Affect Long-Term Survival.

Abstract

Introduction: Abnormal body mass index (BMI) at the time of pediatric heart transplantation (HTx) is a known risk factor for mortality. Whether BMI changes after HTx impacts survival is unknown. Purpose was to stratify post-HTx changes in BMI and study the effects of these changes on HTx survival. Methods: HTx patients with age 2-18y were identified from United Network of Organ Sharing database (1987-2007). Patients with missing BMI information at HTx or at 5y follow-up were excluded. Patients were divided in groups based on percentiles of BMI; wasted (<5th percentile of BMI), normal (5th-95th percentile) or overweight ( ≥95th percentile). Change in BMI at 5y follow-up was classified as Group-1 (normal BMI at 5y) or Group-2 (abnormal BMI at 5y).Table: No Caption available.Results: In total, 35% (718) patients had abnormal BMI at HTx [23% (462) wasted and 12% (256) overweight], however, 31% (629) of all patients had an abnormal BMI at 5y [11% (235) wasted and 19% (394) overweight]. Survival was not affected by abnormal BMI at HTx (median survival: normal-18.3y vs wasted-18.8y p=0.965; vs overweight-15y p=0.205); however, abnormal BMI at 5y adversely affected HTx survival (median survival: normal-18.8y vs wasted-16.2y p=0.007; vs overweight-15.7y p=0.004). With regards to change in BMI at 5y post-HTx, group-1 had improved survival (median survival: group-1 18.8y vs group-2 15.8y; p<0.001). On Cox-regression analysis, group-1 was associated with better HTx survival [HR 1.29; p=0.003]. Conclusion: Abnormal BMI at cardiac transplant does not affect survival; however, abnormal BMI at 5 year post-cardiac transplant decreases survival. Return of BMI to normal within 5 years post-cardiac transplant significantly improves long-term survival. These analyses underline the importance of continuing weight and nutritional management post-cardiac transplantation.