Leading causes of death among adult solid organ transplant recipients in the United States, 1999 to 2019

Underlying medical conditions, graft failure, and immunosuppression place solid organ transplant recipients ("recipients) at heighten risk of death. We report the underlying causes of death among adult US recipients and compare their mortality to the US general population. We obtained causes of death by linking a sample of deaths from the US organ transplant registry to the National Death Index and weighted the linked deaths to represent all deaths among recipients aged [≥]18 years during 1999-2019. To compare mortality to the US general population, we calculated standardized mortality ratios (SMRs). Among 496,467 recipients, 153,491 deaths occurred, of which 99,373 were NDI-linked. Leading causes of death were heart disease (16.9% of deaths), graft failure (14.9%), and cancer (14.4%). Compared to the US general population, recipients had 4.02 times the risk of death, and mortality was elevated for all 16 causes analyzed (e.g., 3.32-fold for heart disease and 2.08-fold for cancer) except dementia/Alzheimers disease. During 2015-2019, overall mortality was elevated 3.08-fold, with lung recipients experiencing the highest elevation (SMR=7.91), followed by heart (3.20), liver (2.86), and kidney (2.81) recipients. Although mortality improved over time, US recipients continue to face substantially elevated mortality, both overall and for common causes of death.