Risk factors for pulmonary embolism in patients with COVID-19: a systemic review and meta-analysis

PURPOSE: To detect the risk factors for pulmonary embolism (PE) in patients with COVID-19. METHODS: Studies were searched for in PubMed, Cochrane Library, Web of Science, and EMBASE. Two authors independently screened articles and extracted data. The data were pooled by meta-analysis and three subgroup analyses were performed. RESULTS: Of the 2210 articles identified, 27 studies were included. Pooled analysis suggested that males (odds ratio (OR) 1.49, 95% confidence interval (CI) 1.26−1.75, P = 0.000), obesity (OR 1.37, 95% CI 1.03−1.82, P = 0.033), mechanical ventilation (OR 3.34, 95% CI 1.90−5.86, P = 0.000), severe parenchymal abnormalities (OR 1.92, 95% CI 1.43−2.58, P = 0.000), ICU admission (OR 2.44, 95% CI 1.48−4.03, P = 0.000), and elevated D-dimer and white blood cell values (at two time points: hospital admission or closest to computed tomography pulmonary angiography) (P = 0.000) correlated with a risk for PE occurrence in COVID-19 patients. However, age and common comorbidities had no association with PE occurrence. Computed tomography pulmonary angiography, unclear-ratio/low-ratio, and hospitalization subgroups had consistent risk factors with all studies; however, other subgroups had fewer risk factors for PE. CONCLUSIONS: Risk factors for PE in COVID-19 were different from the classic risk factors for PE and are likely to differ in diverse study populations.