Venous Thromboembolism in Hospitalized COVID-19 Patients: Systematic Review

Birkeland, Kade; Zimmer, Raymond; Kimchi, Asher; Kedan, Ilan

BACKGROUND: Coagulopathy associated with COVID-19 infection and venous thromboembolism (VTE) have emerged as significant contributors to morbidity among patients infected with SARS-CoV-2. OBJECTIVE: We performed a systematic review to estimate VTE incidence in hospitalized patients and to analyze characteristic factors in the VTE cohort. METHODS: We searched PubMed and Google Scholar using specified title search terms “SARS-CoV-2” or “COVID-19” and “venous thromboembolism” and “anticoagulation” among others to identify peer-reviewed journal articles published between June 22, 2019, and June 22, 2020. Data were systematically extracted and synthesized using Microsoft Excel for analysis. The main outcome was VTE incidence, and measures included patient characteristics, anticoagulation, and clinical outcomes with assessment for associations. RESULTS: In total, 14 studies were included comprising 1677 patients. Most patients (n=1306, 82.4%) received anticoagulation (either VTE prophylaxis or treatment). VTE incidence was 26.9% (SE 3.1; 95% CI 20.8-33.1) and was correlated with systematic screening (r(2)=0.34, P=.03) and study duration (r(2)=–0.33, P=.03). D-dimer was higher for the VTE cohort (5.62 [SD 0.9] vs 1.43 [SD 0.6]; P<.001). Odds of VTE were higher at the intensive care unit (odds ratio [OR] 6.38, 95% CI 3.67-11.11; P<.001) but lower with anticoagulation (OR 0.58, 95% CI 0.36-0.92; P=.02). CONCLUSIONS: Despite the utilization of background anticoagulation, VTE incidence was historically high. Future studies are needed to provide additional data to guide optimal VTE prophylaxis and diagnostic strategies.