Abstract: PO2119
Blood Transfusion and Venous Thromboembolism in Kidney Transplant Patients
Session Information
- Transplantation: Clinical - Underrecognized Risk Factors, Traditional Considerations, and Outcomes
November 04, 2021 | Location: On-Demand, Virtual Only
Abstract Time: 10:00 AM - 12:00 PM
Category: Transplantation
- 1902 Transplantation: Clinical
Author
- Massicotte-Azarniouch, David, University of Ottawa, Ottawa, Ontario, Canada
Background
Receipt of a red blood cell transfusion (RBCT) is common in kidney transplant patients and could have pro-thrombotic effects predisposing to venous thromboembolism (VTE). The aim of this study is to examine the risks for the development of VTE associated with the receipt of RBCT in kidney transplant patients.
Methods
We conducted a retrospective cohort study of all adult kidney transplant recipients at The Ottawa Hospital from 2002 to 2018, using administrative databases and medical chart review. The exposure of interest was receipt of a RBCT after transplant. Cox proportional hazards models were used to calculate hazard ratios (HR) for venous thromboembolism [VTE] (deep venous thrombosis [DVT] or pulmonary embolism [PE]) using RBCT as a time-varying, cumulative exposure.
Results
Out of 1,258 kidney transplants recipients, 468 (37%) received a total of 2,373 RBCT after transplant (incidence of 33 RBCT per 100 patient-years). During follow up, 79 study participants (6.3%) developed VTE, 72 had a DVT (5.7%) and 22 had a PE (1.8%). For the receipt of 1, 2, 3-5 and >5 RBCT, compared to individuals never transfused, the number of events and adjusted HR (95% CI) for VTE was 6 events (6.2%) HR 1.57 (0.69 to 3.58), 9 events (7.6%) HR 2.54 (1.30 to 4.96), 15 events (11.9%) HR 2.73 (1.38 to 5.41) and 23 events (18.1%) HR 5.77 (2.99 to 11.14) respectively; for DVT it was 6 events (6.2%) HR 1.94 (0.84 to 4.48), 9 events (7.6%) HR 2.92 (1.44 to 5.94), 14 events (11.1%) HR 3.29 (1.63 to 6.65) and 21 events (16.5%) HR 6.97 (3.53 to 13.76), respectively. For PE, among transfused individuals there were 14 events (3.0%) and the HR was 2.40 (1.02 to 5.61).
Conclusion
The risk for developing VTE, DVT and PE was significantly associated with the receipt of a RBCT in kidney transplant patients. Receipt of a RBCT should prompt considerations for judicious monitoring and assessment for possible thrombosis.
Cox model HRs for VTE events based on RBCT exposure
Outcome | # RBC units received | # events (%) | Unadjusted HR (95% CI) | Adjusted HR (95% CI)* | Any RBCT vs No RBCT: adjusted HR (95% CI)* |
VTE (DVT or PE) | None 1 2 3-5 >5 | 26 (3.3) 6 (6.2) 9 (7.6) 15 (11.9) 23 (18.1) | Reference 1.85 (0.82 to 4.18) 2.67 (1.38 to 5.16) 3.59 (1.86 to 6.95) 7.45 (3.95 to 14.06) | Reference 1.57 (0.69 to 3.58) 2.54 (1.30 to 4.96) 2.73 (1.38 to 5.41) 5.77 (2.99 to 11.14) | 2.75 (1.73 to 4.38) |
DVT | None 1 2 3-5 >5 | 22 (2.8) 6 (6.2) 9 (7.6) 14 (11.1) 21 (16.5) | Reference 2.25 (0.98 to 5.15) 2.96 (1.47 to 5.95) 4.27 (2.17 to 8.43) 8.90 (4.62 to 17.13) | Reference 1.94 (0.84 to 4.48) 2.92 (1.44 to 5.94) 3.29 (1.63 to 6.65) 6.97 (3.53 to 13.76) | 3.29 (2.01 to 5.40) |
PE | None 1 2 3-5 >5 | 8 (1.0) 3 (3.1) 2 (1.7) 2 (1.6) 7 (5.5) | Reference 2.51 (0.70 to 8.99) 2.08 (0.58 to 7.51) N/A 8.25 (2.77 to 24.58) | Reference 2.42 (0.67 to 8.72) 2.10 (0.58 to 7.57) N/A 7.70 (2.55 to 23.21) | 2.40 (1.02 to 5.61) |
* Adjusted for age, sex, transplant type, PRA, presence of diabetes, presence of cardiovascular disease, and type of maintenance therapy. PE analysis was adjusted only for age given low number of events (22)