PB0941 - COVID-19 is associated with increased risk of bleeding in patients with PE history and undergoing anticoagulation therapy: a multicenter cohort study during omicron pandemic.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and post- acute COVID-19 are closely associated with hypercoagulability and thromboembolic complications. Patients with pulmonary embolism (PE) have an inherent pro-inflammatory state. There is no study focus on the prognosis of previous PE patients under the COVID-19 pandemic.

Aims: To investigate the condition of PE patients under COVID-19, especially the relationship between anticoagulation status and clinical outcomes.

Methods: Observational, multicenter study was performed in seven teaching hospital centers in mainland China, based on the ongoing nationwide cohort study of acute PE. All the patients were diagnosed acute PE between Jan 1st, 2016 and Nov 1st, 2022 .During the omicron pandemic in China between Dec 1st, 2022 to June 1st , 2023 .Patients were followed-up to obtain the disease condition and outcomes related to COVID-19. Overlap weighting based on the propensity score was conducted among comparisons.

Results: 1032 participants with a history of acute PE were enrolled. During the pandemic, 694 (67.2 %) had been diagnosed COVID-19, 47.8% (332) of them were still prescribed anticoagulant. Among the patients without COVID-19, 189 (55.9%) patients were under anticoagulation. Those with COVID-19 had significant higher risk of bleeding among those undertaken anticoagulants (10.5% vs 2.1% without COVID-19, p=0.004), with the adjusted OR of 4.75 (95%CI 1.03-22.21, p=0.045). 202 individuals (29.1%) with COVID-19 reported long COVID-19. Survival curve presented a significant higher and delayed rate of bleeding in those with long COVID (log-rank p=0.015).

Conclusion(s): COVID-19 increased the risk of bleeding in patients with history of PE who were under anticoagulation therapy. Patients with long COVID-19, exhibit a considerably increased but delayed risk of bleeding. Close monitoring of bleeding events and meticulous adjustment of anticoagulation strategies are crucial in the treatment of PE patients with COVID-19, particularly in those with long COVID-19.