A study on nearly 160,000 individuals in the UK shows that unvaccinated people that have been infected with COVID-19 have a higher risk of cardiovascular disease and death for a prolonged period of time. Compared to a cohort of uninfected individuals, their likelihood of dying was 81 times higher in the first three weeks after infection. Even after a year and a half, the risk remained five times higher for people who had been infected compared to those who had not.
“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,” study author Professor Ian C.K. Wong of the University of Hong Kong, said in a statement. “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.”
The data comes from 7,500 people who were infected between March 16 and November 30, 2020, in the UK before the employment of vaccines. They were matched with up to 10 uninfected individuals from the same starting date to the end of August 2021, plus a large historical cohort from before the pandemic (March 16 to November 30, 2018). Groups were matched across possible characteristics and conditions that might lead to cardiovascular diseases such as smoking and high blood pressure.
The inclusion of a pre-pandemic group showed that increases in cardiovascular disease and deaths are not due to the changes in healthcare priorities that took place during the pandemic.
Professor Wong said: “This study was conducted during the first wave of the pandemic, and future research should evaluate subsequent outbreaks. 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.”
The Best Protection Against COVID
Also in the news this week is also a systematic review and meta-analysis of the protection conferred by infection with COVID-19 versus a combination of vaccination and infection, known as hybrid immunity.
The work shows that the protection against reinfection waned after a few months, but the chance of hospital admission or severe disease remained very low. This durability was particularly high with those with hybrid immunity, compared to those who only had the infection.
This was seen as particularly important due to the risk of severe disease due to the omicron variant. Researchers stress that the work’s findings are about a general population and cannot be extrapolated and applied to the most at-risk groups such as older people and those who are immunocompromised and who were not part of this study.
The study on cardiovascular disease risk for unvaccinated COVID-19 patients was published in Cardiovascular Research. The study on the advantages of hybrid immunity was published in The Lancet Infectious Diseases.