Impact of obesity on long term post heart transplantation outcomes

Background: Obesity is an ongoing pandemic, and the rising trend of body mass index (BMI) in heart transplant (HTx) recipients is well known. However, the long term post-HTx outcomes of obese patients are not clearly documented. Aims: We aimed to investigate long term post-transplant outcomes in obese patients. Methods: Among 1787 consecutively enrolled adult HTx recipients between September 1990 and June 2022, patients were categorized into BMI groups: underweight (<18 kg/m²), normal weight (18.0–24.9 kg/m²), overweight (25–29.9 kg/m²), and obese (≥ 30 kg/m²). The primary outcome was post-HTx mortality, with secondary outcomes including primary graft dysfunction, treated rejection, coronary allograft vasculopathy, retransplant, and nonfatal major adverse cardiac event. Results: Over time, there was a significant increase in obese recipients (BMI ≥ 30 kg/m²) and they were more likely to have comorbidities such as diabetes and hypertension, experience significantly longer wait times, and more frequently received undersized donors compared to those with normal weight. During the median follow up duration of 6 years after HTx, obese recipients showed significantly higher incidence of treated rejection (P =0.027) and lower post-HTx survival compared to those with normal weight (P=0.009). In multivariable analysis, obese patients had a significantly higher risk of post-transplant mortality, primary graft dysfunction, and any treated rejection even after adjusting relevant clinical variables. Conclusions: Obese HTx recipients demonstrated a significantly higher risk of death, primary graft dysfunction, and any treated rejection. Our findings highlight the need for proactive, multidisciplinary management of obesity prior to HTx.