Covid: people who catch virus five times more likely to die for up to 18 months after infection

People who catch Covid are at a much greater risk of dying for at least 18 months after being infected, a new study suggests.

The research, published in Cardiovascular Research, a journal of the European Society of Cardiology (ESC), assessed more than 150,000 British participants and found that, compared to uninfected people, the likelihood of Covid patients dying was up to 81 times higher in the first three weeks of infection.

This risk remained five times higher for up to 18 months later, according to the findings. The study also found that the virus is linked with higher risks of a heart attack or stroke in both the short- and long-term.

Researchers compared the occurrence of cardiovascular conditions and death in people infected with the virus, compared to uninfected people, among participants recruited before December 2020, when no vaccines were available in the UK.

More than 7,500 British patients diagnosed with Covid infection from 16 March 16 2020 and 30 November 2020 were identified. Each patient was matched with up to 10 people who did not have Covid during the study period from March 2020 to the end of August 2021, and a group from before the pandemic.

Each uninfected group had more than 70,000 participants who were similar to the Covid group for factors including:

• age
• sex
• smoking
• diabetes
• high blood pressure
• cardiovascular and other health conditions
• body mass index (BMI) 
• ethnicity

In all three groups, the average age was 66 and there were nearly equal numbers of men and women.

Study author Professor Ian Wong, of the University of Hong Kong, said: “The historical control cohort was included to rule out the effect of routine healthcare services being reduced or cancelled during the pandemic, which led to worsening health and increased mortality even in uninfected people.”

Figures were obtained from medical and death records for outcomes including major cardiovascular disease - a composite of heart failure, stroke and coronary heart disease; numerous cardiovascular conditions, including stroke, irregular heartbeat and a heart attack; death from cardiovascular disease; and all-cause death.

Links were evaluated for the acute phase - within 21 days of Covid infection - and the post-acute phase, starting at 22 days after infection and continuing for 18 months.

Covid patients ‘should be monitored for a year’

Patients who were infected with Covid were around four times more likely to develop cardiovascular disease in the acute phase and 40% more likely in the post-acute phase, compared with the two uninfected groups. As for the risk of death, this was up to 81 times higher among Covid patients in the acute phase and five times higher in the latter.

Researchers found that patients with severe Covid were more likely to develop major cardiovascular disease or die than non-severe cases.

Covid patients also had a greater likelihood of several cardiovascular conditions - including a heart attack and deep vein thrombosis - compared with uninfected participants in both the short- and long-term.

Risks of some cardiovascular issues, such as stroke and irregular heartbeat, were elevated in Covid patients in the short-term, but then returned to normal levels.

Study author Professor Ian Wong, of the University of Hong Kong, said: “Covid-19 patients were more likely to develop numerous cardiovascular conditions compared to uninfected participants, which may have contributed to their higher risks of death.

“The findings indicate that patients with Covid-19 should be monitored for at least a year after recovering from the acute illness to diagnose cardiovascular complications of the infection, which form part of long Covid.”

He added: “Previous research has indicated that Covid-19 vaccination may prevent complications, and further studies are needed to investigate its effectiveness in reducing the risks of cardiovascular disease and death after Covid-19 infection in patients with Covid-19 vaccination compared to those without vaccination.”

ESC spokesperson Professor Héctor Bueno, of the National Centre for Cardiovascular Research (CNIC) in Spain, said: “Covid-19 has had a huge impact on patients with cardiovascular disease, who were less likely to receive optimal care during the pandemic and more likely to die from the infection.

“This study shows that Covid-19 also increases the risk of having cardiovascular complications and dying in the first weeks after the infection and remains high for months, suggesting that specific cardiovascular monitoring may be appropriate in these patients.”