Risks associated with prior oral anticoagulation use in hospitalized COVID-19 patients – A retrospective cohort study on 5392 patients from a tertiary centre

Introduction: There are conflicting data on prior oral-anticoagulant (OAC) use and outcomes of hospitalized COVID-19 patients. Due to uncertainties regarding associated risks with the prior OAC use, we have investigated this issue in a large cohort of hospitalized COVID-19 patients from our institution. Methods: We have retrospectively evaluated a total of 5392 consecutive COVID-19 patients hospitalized in our tertiary center institution in period 3/2020 to 6/2021. Majority of patients received low-molecular-weight-heparin thromboprophylaxis and corticosteroids during hospitalization. Patients' characteristics and clinical outcomes were documented as a part of a hospital registry project and were evaluated according to the prior non-OAC, warfarin and direct oral anticoagulants (DOAC) use. Results: Median age was 72 years, median Charlson comorbidity index (CCI) was 4 points. There were 56.2% male patients. Majority of patients had severe (70.5%) or critical (15.8%) COVID-19 on admission. A total of 84.8% patients did not receive prior OAC, 9% were previously anticoagulated with warfarin and 6.2% were previously anticoagulated with DOACs. In the multivariate regression analyses, prior warfarin use was associated increased in-hospital mortality (OR 1.24, P = 0.048) independently of older age (OR 2.12, P < 0.001), male sex (OR 1.27, P < 0.001), higher CCI (OR 1.26, P < 0.001) and severe or critical COVID-19 on admission (OR 22.66, P < 0.001). Prior DOAC use was associated with higher occurrence of major bleeding (OR 1.72, P = 0.045) independently of higher CCI (OR 1.08, P = 0.017). Conclusion: Prior OAC use could be associated with worse clinical outcomes during COVID-19 hospitalization. These phenomena might be OAC type specific and persist after multivariate adjustments

MPN-541 Estimated Plasma Volume Status in Patients With Primary Myelofibrosis and Associated Thrombotic and Mortality Risks

Context: Blood plasma experiences substantial changes in both volume and composition in patients with chronic myeloproliferative neoplasms (MPN) and represents a large reservoir of cytokines and other mediators of inflammation. Higher estimated plasma volume status (ePVS) has recently been shown to correlate with increased thrombotic risk in polycythemia vera patients. Objective: To estimate clinical and prognostic associations of ePVS in patients with myelofibrosis. Design: Retrospective cohort study. Setting: 6 hematology centers. Patients: 238 myelofibrosis patients, 168 with PMF, 34 with post-PV SMF and 36 with post-ET SMF. Interventions: ePVS was calculated using the Strauss derived Duarte formula: (100-hematocrit (%)/hemoglobin (g/dL) and expressed as dl/g. Main outcome measures: Overall survival (OS) and time to thrombosis (TTT). Results: Median ePVS was 5.8 dl/g and it did not significantly differ between PMF and SMF patients. Among other associations, higher ePVS was significantly associated with higher degree of bone-marrow fibrosis, absence of JAK2-mutation, lower white blood cells (WBC), platelets and hemoglobin, presence of circulatory blasts, higher C-reactive protein, higher lactate dehydrogenase, lower albumin and higher Charlson comorbidity index in an overall cohort, as well as with more pronounced splenomegaly and higher Dynamic International Prognostic Scoring System (DIPSS) risk in primary myelofibrosis (PMF) and higher Mysec-PM risk in secondary myelofibrosis (SMF) patients (P5.6 dl/g) was associated with shorter overall-survival (OS) in PMF (HR=2.8, P7 dl/g, HR=4.1, P=0.009) patients. Associations with overall survival diminished in multivariate analyses after adjustments for DIPSS and Mysec-PM, respectively. Association with TTT remained significant independently of JAK2, WBC and chronic kidney disease. Conclusions: Myelofibrosis patients with more advanced disease features and more pronounced inflammation have higher ePVS, indicative of expanded plasma volume. Higher ePVS is associated with impaired survival in PMF and SMF and higher thrombotic risk in PMF patients