Venous thromboembolic events in patients with COVID-19: a systematic review and meta-analysis

Background High incidence of venous thromboembolic complications in coronavirus disease 2019 (COVID-19) patients was noted recently. Objective This study aimed to explore the factors associated with prevalence of venous thromboembolism (VTE) in COVID-19 patients. Methods A literature search was conducted in several online databases. Fixed effects meta-analysis was performed for the factors associated with prevalence of VTE in COVID-19 patients. Results A total of 39 studies were analysed in this analysis. The incidence of pulmonary embolism and VTE in severe COVID-19 patients were 17% (95% CI, 13-21%) and 42% (95% CI, 25-60%), respectively. VTE were more common among individuals with COVID-19 of advance age. Male COVID-19 patients are more likely to experience VTE. Higher levels of white blood cell (WBC; WMD = 1.34x10(9)/L; 95% CI, 0.84-1.84x10(9)/L), D-dimer (WMD = 4.21 mu g/ml; 95% CI, 3.77-4.66 mu g/ml), activated partial thromboplastin time (APTT; WMD = 2.03 s; 95% CI, 0.83-3.24 s), fibrinogen (WMD = 0.49 mu g/ml; 95% CI, 0.18-0.79 g/L) and C-reactive protein (CRP; WMD = 21.89 mg/L; 95% CI, 11.44-32.34 mg/L) were commonly noted in COVID-19 patients with VTE. Patients with lower level of lymphocyte (WMD = -0.15x10(9)/L; 95% CI, -0.23- -0.07x10(9)/L) was at high risk of developing VTE. The incidence of severe condition (OR = 2.66; 95% CI, 1.95-3.62) was more likely to occur among COVID-19 patients who developed VTE. Conclusion VTE is a common complication in severe COVID-19 patients and thromboembolic events are also associated with adverse outcomes.

Automated summary

Venous thromboembolism (VTE) is common in severe COVID-19 patients, with higher incidence in older individuals and male patients. Elevated levels of WBC, D-dimer, APTT, fibrinogen, and CRP were commonly observed in COVID-19 patients with VTE, while lower level of lymphocyte was associated with high risk of developing VTE. Severe condition was more likely to occur in COVID-19 patients who developed VTE, suggesting that thromboembolic events are associated with adverse outcomes in COVID-19 patients.