Venous thromboembolism in lung transplant recipients: timing and clinical impact, a 10-year cohort analysis

Introduction: The burden of venous thromboembolism (VTE) in lung transplant (LTx) recipients is not fully elucidated despite its frequent occurrence. We report the incidence of VTE and characteristics of VTE in a large LTx cohort, assess severity using risk stratification algorithms, and explore associations with graft survival and chronic lung allograft dysfunction (CLAD). Methods: A retrospective cohort analysis was performed on LTx recipients transplanted between July 2012 and August 2022 in our center. Primary outcome was incidence of VTE. Three groups were compared as follows: patients with early VTE (i.e., within the first 6 months after LTx), late VTE (i.e., beyond the first 6 months after LTx), and no VTE. Results: About 94/286 patients (33%) were diagnosed with VTE (median follow-up of 4.3 years): 67/94 (71%) early VTE and 27/94 (29%) late VTE. 66/94 (70%) of VTE events were pulmonary embolism (PE). In the early VTE group, none of the PE cases were classified as intermediate-high risk PE and 1 patient had high-risk (fatal) PE. Graft survival was not different between groups; median CLAD-free survival was shorter in patients with late VTE (6.2 years) compared to patients without VTE during follow-up (9.8 years) (p = 0.044). Conclusions: Thirty-three percent of LTx recipients developed VTE, 71% within the first 6 months after LTx. Seventy percent of cases were acute PE, but fatal or severe nonfatal PE were rare. No effect of VTE on graft survival was seen; CLAD-free survival was shorter in patients with late VTE compared to patients without VTE.