P1675: POST-HOSPITAL DISCHARGE EVALUATION OF COVID-19 SURVIVORS WHO SUFFERED ACUTE VENOUS THROMBOEMBOLISM (VTE) DURING HOSPITALIZATION: THE BERGAMO EXPERIENCE

Abstract

Background: Acute COVID-19 manifestations are well known, while post-COVID clinical and laboratory consequences are less clear. Due to the strict association of COVID-19 with thrombosis, the Hemostasis Service of Bergamo hospital had a central role in guiding anticoagulant treatments in patients during the acute and post-discharge phases. Aims: In the post-hospital discharge setting, in a cohort of COVID-19 survivors who experienced VTE during the acute phase and were followed up at our outpatient clinic, we aim to evaluate whether alterations in coagulation and inflammatory parameters were occurring and were possibly associated with disease severity. Methods: An outpatient service specifically dedicated to follow-up of COVID-19 survivors was set up at our Institution. A retrospective analysis of a cohort of 1563 patients enrolled from May 2020 to November 2020 was performed. Data were obtained on the occurrence or not of acute COVID-19 -associated VTE, the site of thrombosis, ongoing anticoagulant treatments, and the results of laboratory tests performed at the first post-discharge assessment visit, including blood cell count, D-dimer, fibrinogen, CRP and LDH. The severity degree of COVID-19 at the onset was defined by the need of Continuous Positive Airway Pressure devices (C-PAP) or tracheal intubation as compared to no-oxygen need, or use of nasal flow, reservoir mask, or Venturi Mask. Statistical analyses were performed using SPSS v21 software. Results of lab tests were expressed as median values (5th-95th percentile). Results: Of the 1563 enrolled outpatient COVID-19 survivors [974 M/589 F, median age of 60 years (35.5-81)], 56 subjects [43M/13F; median age 62 years (42-80.5)] had had VTE during COVID-19 acute phase (3.58%), as follows: 9 isolated proximal DVT (4 in upper extremity), 45 isolated PE (34 subsegmental and/or segmental PE; 11 central pulmonary artery thrombosis), 2 DVT+PE. Concerning COVID-19 severity, 33 of 56 patients needed C-PAP or tracheal intubation. At the follow-up visit, patients were still on anticoagulation (76% with DOAC). Laboratory data analyses revealed that 25% of VTE-subjects had increased levels of both D-dimer and fibrinogen, and 11% had elevated levels of CRP, while no abnormalities were observed in the platelet and leucocyte counts. CRP significantly correlated with fibrinogen and D-Dimer levels. According to COVID-19 severity, only platelet count was significantly higher in patients with severe disease, who needed C-PAP or tracheal intubation, as compared to those with less severe disease. No patients had VTE recurrence or bleeding complications at the time of follow up. Summary/Conclusion: Our data suggest persistence of pro-coagulant and inflammatory laboratory patterns in a proportion of patients with COVID-19-related VTE, in spite of anticoagulant therapy. Further studies are needed to establish on whether monitoring these parameters may help in the decision on the duration of anticoagulation in this condition.