Clinical Predictors, Regional Variation and Temporal Trends of Weight Gain after Heart Transplant: An Analysis of the ISHLT Transplant Registry

Abstract

Overweight and obesity are associated with an increased risk for adverse cardiac and non-cardiac outcomes. Weight gain is common after heart transplantation (HT). We aimed to identify clinical predictors and temporal trends of total body weight (TBW) change following HT. We included 15,182 adult HT recipients from the ISHLT Transplant Registry transplanted between 1996 and 2016 who survived to 1 year and for whom serial body weight data was recorded. We categorized HT eras as E1 (1996-2000), E2 (2001-2005), E3 (2006-2010) and E4 (2011-2016). The proportion of patients with obesity at transplant has increased over time - E1: 18%, E2: 22%, E3: 25%, E4: 27%, p<0.05. After transplant, body weight increased in all eras, however the percent change in TBW between transplant and 1 year (ΔTBW%) decreased over time - E1: 7.7%, E2: 4.6%, E3 3.5%, E4 1.6%; p<0.001 (Figure 1A). While more male than female patients were obese at the time of transplant (23.6 vs 20.8, p<0.001), female patients had higher ΔTBW% (5.0% vs 4.2%, p<0.001). Significant regional differences were also identified. In North America compared to Europe & Other Regions, more patients were obese at transplant (24% vs 14%, p<0.001), and ΔTBW% was also higher in North America (5.2% vs 0% p<0.001). The factors independently associated with above median ΔTBW% are shown in Figure 1B and included younger recipient age, lower recipient BMI at transplant, earliest transplant era, transplant in North America, cyclosporine therapy, and the use of steroids at 1 year after transplant. More recent transplant eras are associated with more obesity at the time of transplant but less weight gain between transplant and 1 year. Marked regional differences in weight gain after transplant provide an opportunity for designing effective interventions for weight gain prevention.