RISK FACTORS AND PREVALENCE OF VTE IN LUNG TRANSPLANT PATIENTS AND ITS IMPACT ON OUTCOME

Abstract

SESSION TITLE: Transplantation Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: Venous thromboembolism (VTE) is common in the post-solid organ and bone marrow transplant population. In lung transplant patients, VTE incidence ranges from 1.78-45%. Whether its occurrence in the post-lung transplant setting jeopardizes long term allograft outcome is unclear. Our aims were to identify the prevalence and risk factors associated with VTE post-lung-transplant, and to assess survival rate after VTE. METHODS: We performed a retrospective review of 126 patients within a large urban HMO cohort who underwent lung transplantation between 2003 and 2016. Patients were followed until the end of December 2017. Patient demographic information, underlying lung disease requiring transplant, results of testing for DVT or PE and survival statistics were gathered. RESULTS: We identified 147 post lung transplant patients in the Kaiser Permanente Southern California database. 15 were excluded due to a lack of data, 4 excluded due to pre-transplant VTE, and 2 excluded due to age < 18 at time of transplant. The population was male-predominant (63.5%) with median age of 60 (range 20-75 years). 54% were non-Caucasians. Among 126 patients included, 31 were diagnosed with VTE (24.6%, 15 with pulmonary emboli, 22 with deep venous thrombosis, 6 with both). These occurred at a median of 168 days after transplant (mean 660 days, range 1-3526 days). There was no significant difference in age (p=0.2677) or gender (p=0.3194). VTE patients were more likely to be Caucasian (74.2% in VTE to 36.8% in non-VTE, p=0.0003) and more likely to have COPD (27.3% in VTE to 7.1% in non-VTE, p=0.0118). Crude hazard ratios for survival and hazard ratios adjusted for age, gender, and ethnicity were not statistically significant (1.293, p=0.395; 1.306, p=0.433). Similarly, there was no statistical significance in these hazard ratios at 1 year (1.873, p=0.39; 1.692, p=0.518), 3 years (1.323, p=0.415; 1.044, p=0.906), 5 years (0.852, p=0.568; 0.744, p=0.327), or 7 years (0.796, p=0.346; 0.765, p=0.312) post-transplant. CONCLUSIONS: The VTE prevalence in our population is high. There was an association with VTE in Caucasian patients and COPD patients. Review of the calculated hazard ratios and Kaplan-Meier curves suggests a trend toward worsened survival for patients who suffered VTE in the overall hazard ratio and at 1 and 3 years post-transplant, although these did not reach statistical significance. This trend seems to reverse at 5 and 7 years, raising the question of whether VTE worsened survival in the initial post-transplant period. CLINICAL IMPLICATIONS: This study demonstrates that VTE in the post lung transplant population can be quite common. It may have a negative effect on survival in the early post-transplant period. Increased attention to prophylaxis and heightened suspicion for occurrence of VTE disease in this period may be necessary. DISCLOSURES: No relevant relationships by Oragun Rojanapairat, source=Web Response No relevant relationships by Tim Shen, source=Web Response No relevant relationships by Nirmala Surapaneni, source=Web Response No relevant relationships by Mariam Torossian, source=Web Response No relevant relationships by Kenneth Wei, source=Web Response