Researchers Say COVID-19 Patients Have A Risk Of Blood Clots For Up To Six Months

JAKARTA - People who have COVID-19 are at increased risk of serious blood clots for up to six months, according to a new study.

Researchers found the risk of deep vein thrombosis (DVT) was "significantly increased" for three months after COVID-19 infection, six months for pulmonary embolism, or blockage of a blood vessel in the lungs and two months for bleeding.

The findings suggest people with underlying health problems are most at risk, as are those with more severe COVID-19. The risk is higher during the first wave of the pandemic compared to the second and third waves.

Citing The National News, April 7, the researchers said this could reflect the role of vaccines and treatments, especially for the elderly, in reducing their chances of suffering complications.

The team of experts behind the study, which was published in the 'British Medical Journal' also said the findings were important to offer some patients a drug to prevent clots.

For the study, experts from the University of Umea in Sweden looked at data on more than one million people in the country who tested positive between February 2020 and May 2021. They were compared with more than four million people without the virus.

The team also looked at the risk of clotting in the period after COVID symptoms started, compared to long before people tested positive and long after symptoms had disappeared.

The results showed 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 within 30 days of infection.

In absolute terms, this means that the first DVT occurred in 401 patients with COVID-19 (0.04 percent absolute risk) and 267 patients without (0.01 percent absolute risk) during this period.

Meanwhile, the first pulmonary embolism occurred in 1.761 patients with COVID (absolute risk 0.17 percent) and 171 without (absolute risk 0.004 percent).

The first bleeding occurred in 1,002 patients with COVID (0.10 percent absolute risk) and 1.292 without (0.04 percent absolute risk).

The risk persists for most patients over a period of six months.

"Our findings arguably support thromboprophylaxis (preventive treatment) to avoid thrombotic events, especially for high-risk patients, and reinforce the importance of vaccination against COVID-19," the team concludes.