Weight gain post-heart transplantation is associated with an increased risk for allograft vasculopathy and rejection

Obesity and overweight are associated with an increased risk for cardiovascular disease. Since fat mass (FM) and fat-free mass (FFM) both contribute to total body weight (TBW), we characterized the post-heart transplantation (HT) change in TBW and its implications for outcomes.

Post-HT changes in TBW, FM, and FFM were reviewed for 211 HT patients assessed during 1997-2017. Endpoints included cardiac allograft vasculopathy (CAV) and rejection.

Median TBW increased by 7.3% at 1 year, with a significant rise in the obese category (28% vs. 13%, p < 0.001) and with FM versus FFM making the main contribution (23% vs. 3%, p < 0.001). When patients were divided according to median TBW change ("high" vs. "low"), Kaplan-Meier analysis showed that 10-year freedom from CAV (log-rank p < 0.005) and rejection (log-rank p < 0.01) was significantly higher for the "low" TBW change group. Consistently, multivariable analyses showed that the "high" group was independently associated with significant 3.5-fold and 4.2-fold increased risks for CAV (95% CI 1.4-8.7, p = 0.01) and rejection (95% CI 1.2-15.4, p = 0.03), respectively.

Weight gain, contributed mostly by FM, is independently associated with an increased risk for CAV and rejection. Follow-up emphasis should be placed on weight gain and preventative measures.