Clopidogrel use as a risk factor for poor outcomes after kidney transplantation.

Background: Limited data are available on outcome implications of clopidogrel use before kidney transplantation.

Methods: A novel dataset linking national transplant registry data with records from a large pharmacy claims clearinghouse (2005 to 2010) was examined to estimate risks of post-transplant death and graft failure associated with clopidogrel fills within 90 or more than 90 days before transplant.

Results: Clopidogrel fills within 90 days of transplant were associated with 61% of increased relative mortality risk and 23% of increased graft failure risk. Risks were higher in those whose last clopidogrel fill was more than 90 days before transplantation (111% for death, 59% for graft loss). Adverse prognostic associations persisted among recipients of live and deceased donor allografts, older recipients, and those with diabetes or reported cardiovascular disease.

Conclusions: Clopidogrel use before kidney transplantation portends increased risks of post-transplant death and graft loss. Pharmacy claims may identify novel prognostic markers not currently captured in the transplant registry.