Heterogeneity in reporting venous thromboembolic phenotypes in COVID-19: methodological issues and clinical implications.

COVID-19 is associated with increased risk of venous thromboembolic events (VTE). However, there is significant heterogeneity in the thromboembolic phenotypes of COVID-19 patients (deep vein thrombosis, pulmonary embolism/thrombosis). The latter might be partly attributed to the variation in VTE risk factors in COVID-19 patients including: (i) patients' characteristics; (ii) hospitalization conditions and interventions; and (iii) SARS-CoV-2-specific factors (coagulopathy, endothelial injury/microthrombosis). Furthermore, there is methodological heterogeneity in relation to the assessment of VTE (indications for screening, diagnostic methodology, etc). Physicians should be aware of the increased VTE risk, strongly consider VTE screening, and use thromboprophylaxis in all hospitalized patients.