Extended thromboprophylaxis may not be needed for COVID-19 patients once they leave hospital, say Belgian researchers presenting the first data on post-discharge rates of venous thromboembolism (VTE).
Results from a study presented at the International Society on Thrombosis and Haemostasis (ISTH) virtual conference, suggest that the incidence of VTE is less than 1% in patients hospitalised for COVID-19 once they return home.
Presenting the data, Matthias Engelen from University Hospitals Leuven in Belgium said in hospitalised COVID-19 patients D-dimer levels are often high and a predictor of mortality and the incidence of VTE can be up to 30%-50%.
As a result, thromboprophylaxis with a prophylactic or intermediate dose of low molecular weight heparins has become the standard of care but little is known about the incidence post discharge, he said.
So far official recommendations on extended prevention therapy have been mixed with an expert panel published in Chest recommending thromboprophylaxis only in hospital unless the emerging data suggests a benefit of extended therapy after discharge but the ISTH guidance advocating the consideration of extended treatment in selected patients with risk factors and low risk of bleeding.
In an analysis of 102 patients with a mean age of 57 years, the team measured D-dimer levels and did venous ultrasound screening at six weeks after discharge.
The patients at highest risk – those who who admitted to intensive care or had D-dimer levels greater than 2000 ng/mL – also underwent CT pulmonary angiogram or a ventilation/perfusion lung scan.
In all 26 patients had been in intensive care, 44% of them needing mechanical ventilation.
The research showed that mean D-dimer levels were significantly lower at follow-up (593 ng/mL) compared to discharge (1101 ng/mL).
Only 8% of patients received prophylactic LMWHs after discharge (mean 13 days) without major or clinically relevant bleedings. There were no symptomatic VTE cases. The screening tests done as part of the study revealed only one asymptomatic VTE
“These results suggest that extended thromboprophylaxis after hospitalisation is not routinely needed,” he concluded.
Professor Beverley Hunt professor of thrombosis and haemostasis at King’s College, London commented that the low rates seen in the study were “good news”.
“Awaiting publications from other centres to confirm these findings,” she said on Twitter.