The impact of COVID-19 on the prognosis of deep vein thrombosis following anticoagulation treatment: a two-year single-center retrospective cohort study

Coronavirus disease 2019 (COVID-19) has been proved as a significant risk factor for deep vein thrombosis (DVT) after several waves of pandemic. This study aims to further investigate impact of COVID-19 on prognosis of DVT following anticoagulation treatment.

A total of 197 patients with initially detected DVT and meanwhile accomplishing at least 3 months anticoagulation treatment were identified from our hospital between January 2021 and December 2022. DVT characteristics, clinical data, and exposure to COVID-19 were recorded for multivariable logistic regression analysis to identify DVT aggravation related risk factors. Propensity score matching (PSM) was used to balance baseline covariates. Kaplan–Meier curves and Log-Rank test were performed to exhibit distribution of DVT aggravation among different subgroups.

In 2022, patients exhibited higher incidence rates of DVT aggravation compared to those in 2021 (HR:2.311, P = 0.0018). The exposure to COVID-19, increased red blood cell count, increased D-dimer level and reduced prothrombin time were found to be associated with DVT aggravation (P < 0.0001, P = 0.014, P < 0.001, P = 0.024), with only exposure to COVID-19 showing a significant difference between two years (2022:59/102, 57.84%, 2021:7/88, 7.37%, P < 0.001). In PSM-matched cohorts, the risk for DVT aggravation was 3.182 times higher in COVID-19 group compared to the control group (P < 0.0001). Exposure to COVID-19 increased the risk of DVT aggravation among patients who completed three months anticoagulant therapy (HR: 5.667, P < 0.0001), but did not increase incidence rate among patients who completed more than three months anticoagulant therapy (HR:1.198, P = 0.683). For patients with distal DVT, COVID-19 was associated with a significant increased risk of DVT recurrence (HR:4.203, P < 0.0001). Regarding principal diagnoses, incidence rate of DVT aggravation was significantly higher in COVID-19 group compared to the control group (Advanced lung cancer: P = 0.011, surgical history: P = 0.0365, benign lung diseases: P = 0.0418).

Our study reveals an increased risk of DVT aggravation following COVID-19 during anticoagulation treatment, particularly among patients with distal DVT or those who have completed only three months anticoagulant therapy. Adverse effects of COVID-19 on DVT prognosis were observed across various benign and malignant respiratory diseases. Additionally, extended-term anticoagulant therapy was identified as an effective approach to enhance DVT control among patients with COVID-19.