London: People infected with COVID-19 are at increased risk of deep vein thrombosis – a blood clot in the leg – for up to three months, pulmonary embolism – a blood clot in the lung – for up to six months, and the occurrence of bleeding for up to two months, one study finds. Findings published by The BMJ also showed a higher risk of events in patients with underlying conditions and patients with more severe COVID-19.
Researchers from Ume University in Sweden said these results support measures to prevent thrombotic events (thromboprophylaxis), especially for high-risk patients, and strengthen the importance of vaccination against COVID-19. It is well known that COVID increases the risk of serious blood clots (known as venous thromboembolism or VTE), but little evidence exists about the duration of this risk increase if the risk changes during pandemic waves. and whether covid also increases the risk of major bleeding.
To address these uncertainties, the researchers set out to measure the risk of deep vein thrombosis, pulmonary embolism and bleeding after COVID-19. For the study, the team identified more than one million people with confirmed COVID infections between February 1, 2020 and May 25, 2021, and matched them with more than four million people who had positive SARS- There was no CoV-2 test result.
The researchers found that there was a five-fold increase in the risk of deep vein thrombosis, a 33-fold increase in the risk of pulmonary embolism, and a nearly two-fold increase in the risk of bleeding in the 30 days following infection. The risk was highest in patients with more severe COVID-19 and during the first pandemic wave than in the second and third waves, which the researchers say may be explained by improvements in treatment and vaccine coverage in older patients after the first wave. Even among mild, non-hospitalized COVID patients, researchers found an increased risk of deep vein thrombosis and pulmonary embolism.
No increased risk of bleeding was found in mild cases, but a significant increase was observed in more severe cases. “This is an observational study, so researchers cannot establish the cause,” the researchers said. programmes, especially for high-risk patients, and reinforce the importance of vaccination against COVID-19,” he said.