Incidence of Venous Thromboembolism in Hospitalized Coronavirus Disease 2019 Patients: A Systematic Review and Meta-Analysis

Background: Emerging evidence shows that coronavirus disease 2019 (COVID-19) is commonly complicated by coagulopathy, and venous thromboembolism (VTE) is considered to be a potential cause of unexplained death. Information on the incidence of VTE in COVID-19 patients, however, remains unclear. Method: English-language databases (PubMed, Embase, Cochrane), Chinese-language databases (CNKI, VIP, WANFANG), and preprint platforms were searched to identify studies with data of VTE occurrence in hospitalized COVID-19 patients. Pooled incidence and relative risks (RRs) of VTE were estimated by a random-effects model. Variations were examined based on clinical manifestations of VTE (pulmonary embolism-PE and deep vein thrombosis-DVT), disease severity (severe patients and non-severe patients), and rate of pharmacologic thromboprophylaxis (≥60 and <60%). Sensitivity analyses were conducted to strengthen the robustness of results. Meta-regression was performed to explore the risk factors associated with VTE in COVID-19 patients. Results: A total of 17 studies involving 1,913 hospitalized COVID-19 patients were included. The pooled incidence of VTE was 25% (95% CI, 19–31%; I(2), 95.7%), with a significant difference between the incidence of PE (19%; 95% CI, 13–25%; I(2), 93.2%) and DVT (7%; 95% CI, 4–10%; I(2), 88.3%; P(interaction) < 0.001). Higher incidence was observed in severe COVID-19 patients (35%; 95 CI%, 25–44%; I(2), 92.4%) than that in non-severe patients (6%; 95 CI%, 3–10%; I(2), 62.2%; P(interaction) < 0.001). The high rate of pharmacologic thromboprophylaxis in COVID-19 patients (≥60%) was associated with a lower incidence of VTE compared with the low pharmacologic thromboprophylaxis rate (<60%) (19 vs. 40%; P(interaction) = 0.052). Severe patients had a 3.76-fold increased risk of VTE compared with non-severe patients (RR, 4.76; 95% CI, 2.66–8.50; I(2), 47.0%). Sensitivity analyses confirmed the robustness of the primacy results. Conclusions: This meta-analysis revealed that the estimated VTE incidence was 25% in hospitalized COVID-19 patients. Higher incidence of VTE was observed in COVID-19 patients with a severe condition or with a low rate of pharmacologic thromboprophylaxis. Assessment of VTE risk is strongly recommended in COVID-19 patients, and effective measures of thromboprophylaxis should be taken in a timely manner for patients with high risk of VTE.