Hospitalized patients with Covid-19 are at high risk of developing a VTE. However, this risk is defined by the severity of the illness, suggests a new meta-analysis published in the Thrombosis Journal.

A systematic review and meta-analysis was conducted to examine the risk of VTE in patients hospitalized for Covid-19. The meta-analysis included 33 studies involving 4009 hospitalized patients with diverse thrombotic risk factors. Outcomes were major VTE, defined as any objectively diagnosed pulmonary embolism (PE) and/or proximal deep vein thrombosis (DVT).

“Proximal DVT was defined as lower limb DVT occurring in the popliteal, femoral, iliac veins and/or inferior vena cava, regardless of the presence of a catheter, and confirmed by compression ultrasound (CUS) or CT phlebography.” 

“PE had to be objectively confirmed by CTPA, ventilation/perfusion scintigraphy, the presence of a proximal DVT on lower limb CUS in a patient with clinical suspicion of PE, or a high clinical suspicion of PE with an acute right ventricular dilatation on echocardiography.”

The overall incidence of VTE among patients with COVID-19 hospitalized in the medical ward and/or ICU was found to be 9%.

In patients admitted to medical wards, the incidence of proximal lower limb DVT incidence was 3% and that of PE was 8%. The corresponding VTE rates were quite high in patients admitted to the ICUs, where the overall incidence rate of VTE was 21% and that of proximal lower limb DVT was 8%, while the incidence of PE was 17%.

VTE risk was just 2% when only patients hospitalized in general medical wards were assessed.

Risk of VTE was found to be overall higher in studies that had a screening protocol compared to studies without screening. The VTE rate was 5% without screening, while it was 11% with screening. Expectedly, the risk was much higher when no anticoagulant treatment was given compared to prophylactic and therapeutic anticoagulation; 29.4%, 19.8% and 7.1%, respectively.

This study has shown that hospitalized Covid-19 patients are at risk of developing a VTE; patients receiving intensive care are particularly at risk.

Initially considered a respiratory disease, Covid-19 is now recognised as a prothrombotic state, which predisposes to thrombosis, predominantly VTE and adversely affects prognosis. According to the study authors, other factors too may contribute to the hypercoagulable state in these patients such as prolonged immobility and frequent use of muscle relaxant drugs in patients with ARDS.

This study points out the need for thromboprophylaxis in patients with severe Covid-19. It further highlights that it is important to keep an eye out for risk of thrombosis and initiate timely thromboprophylaxis in all hospitalized patients with Covid-19.

Reference

1. Longchamp G, et al. Proximal deep vein thrombosis and pulmonary embolism in COVID-19 patients: a systematic review and meta-analysis. Thromb J. 2021 Mar 9;19(1):15. doi: 10.1186/s12959-021-00266-x