Risk of blood clots in lungs doubles for Covid survivors, study says

Health records of almost two million people - around 353,000 of whom had the virus - were examined

One in five people who catch Covid-19 are likely to go on to develop another health condition, research says.

The study from the US Centres for Disease Control and Prevention found survivors were twice as likely to develop a pulmonary embolism or respiratory illness compared to people who were never infected.

A pulmonary embolism is a clot that develops in a blood vessel that travels to an artery that goes from the heart to the lungs, which can block the normal flow of blood.

Researchers studied the electronic health records of almost two million people, around 353,000 of whom had the virus, from March 2020 to November last year.

One in five of those who had the virus in the 18–64 age group and one in four survivors aged 65 years or older experienced at least one 'incident,' such as a blood clot or pulmonary embolism, that might be attributable to a previous infection.

“Among all patients aged 18 years or older, 38 per cent of case-patients experienced an incident condition compared with 16 per cent of controls (those who were not infected). Conditions affected multiple systems and included cardiovascular, pulmonary, hematologic, renal, endocrine, gastrointestinal, musculoskeletal, neurologic, and psychiatric signs and symptoms,” said the researchers.

“By age group, the highest risk ratios were for acute pulmonary embolism and respiratory signs and symptoms.

“Among those aged 18–64 years, 35.4 per cent of case-patients experienced an incident [or] condition compared with 14.6 per cent of controls.

“Among those aged 65 years or older, 45.4 per cent of case-patients experienced an incident [or] condition compared with 18.5 per cent of controls.”

Doctors in the UAE said they have seen patients go on to develop respiratory conditions after having Covid-19.

“Some patients are developing asthma-like symptoms, which means in the next six months they are going to be using an inhaler frequently,” said Dr Ahmed ElMansoury, a consultant pulmonologist at NMC Royal Hospital, Sharjah.

Other patients have developed fibrosis, or scarring on their lungs, which makes breathing difficult.

“We have delayed symptoms, which is a complication of the Covid itself, in the form of lung fibrosis, which is a consequence of severe Covid pneumonia,” he said.

Dr Emadeldin at NMC Royal Hospital, Sharjah, said some people, especially those who had severe Covid-19, experience multi-organ effects or autoimmune conditions with symptoms lasting weeks or months after contracting the virus.

“Multi-organ effects can involve many body systems, including the heart, lung, kidney, skin, and brain,” he said.

“As a result of these effects, people who have had Covid-19 may be more likely to develop new health conditions such as diabetes, heart conditions, or neurological conditions compared with people who have not had Covid-19.”

Previous research found people infected with Covid-19 stand a much greater chance of suffering a heart attack or stroke.

People who contracted Covid-19 were 72 per cent more likely to have coronary artery disease, 63 per cent more likely to have a heart attack and 52 per cent more likely to have a stroke.

Studies also said Covid-19 survivors have a one-in-five chance of developing a mental illness.