Venous thromboembolism in solid-organ transplant recipients: Findings from the RIETE registry

Background: Venous thromboembolism (VTE) represents a relevant cause of morbidity in patients with solid-organ transplant (SOT), but there are scarce data on the management and outcomes in these patients.

Methods: RIETE is a worldwide, ongoing observational registry of patients with objectively confirmed, acute VTE. We used the RIETE database to compare the clinical characteristics, treatment and outcomes in SOT recipients vs. non-recipients.

Results: From January 2001 to December 2019, 83,210 patients were enrolled in RIETE. Of these, 329 (0.4%) were SOT recipients: in the kidney 221, liver 41, lung 28 and heart 25. Median duration of anticoagulation was similar in SOT recipients and non-recipients (174 vs. 182 days). During anticoagulation, 1180 patients developed deep vein thrombosis (DVT) recurrences, 1028 pulmonary embolism (PE) recurrences, 2392 had major bleeding, 3119 non-major bleeding and 8157 died. SOT recipients had a higher rate of major bleeding (hazard ratio [HR]: 2.55; 95% CI: 1.62-3.84) and clinically relevant non-major bleeding (HR: 1.94; 95% CI: 1.23-2.93) than non-recipients, with no differences in the rates of DVT recurrences (HR: 0.96; 95% CI: 0.30-2.32), PE recurrences (HR: 1.11; 95% CI: 0.35-2.67) or death (HR: 0.98; 95% CI: 0.67-1.40). On multivariable analysis, only liver transplant recipients were at an increased risk for major bleeding compared to non-recipients (adjusted HR: 3.17; 95% CI: 1.02-9.87).

Conclusions: Treatment of VTE in SOT recipients is associated with an increased risk of bleeding compared to non-recipients. This is mainly due to the influence of liver transplant recipients. In non-liver SOT recipients, the risk for bleeding was similar to that in non-recipients.