London School of Hygiene & Tropical Medicine

People with elevated risk of developing a stroke or heart attack over the next 10 years, but without existing cardiovascular disease (CVD), who contract COVID-19 are six times as likely to die from COVID-19, compared to those at low cardiovascular risk, according to new research to be presented at this year’s European Congress of Clinical Microbiology & Infectious Diseases (ECCMID).

The study, which is not yet peer-reviewed, also found this group is three times as likely to be hospitalised and require treatment in intensive care.

Carried out by London School of Hygiene & Tropical Medicine, the research was conducted using data on almost a million adults across England from the first wave of the pandemic in 2020.

These findings emphasise the importance of COVID-19 vaccination and investing in strategies to improve cardiovascular health that could reduce the severity of COVID-19 across the population.

Throughout the pandemic, chronic health conditions such as CVD have been associated with the most severe outcomes including hospitalisations and deaths. CVD includes coronary heart disease (angina and heart attack), stroke, and transient ischaemic attacks. However, people at raised cardiovascular risk, but without existing CVD, have not been identified as a risk group for severe COVID-19. 

Jennifer Davidson, from LSHTM and study author, said: “Our study is one of the largest population-based studies with a comprehensive measure of cardiovascular risk. Although the risk of contracting COVID-19 infection appears similar among individuals with raised and low cardiovascular risk, the occurrence of severe outcomes is far higher in those at elevated risk.”

The team used the electronic medical records of 949,973 adults, aged 40-84 years who were registered at GP practices across England, to calculate the incidence and risk of COVID-19 (based on laboratory-confirmed SARS-CoV-2), and severe COVID-19 (defined as death, intensive care unit (ICU) admission and hospitalisation) among adults at raised and low cardiovascular risk.

They used factors such as body mass index, smoking history, blood pressure, cholesterol, age, social deprivation and ethnicity to estimate a person’s risk of future CVD. Those estimated to have a 10% or higher chance of a heart attack or stroke within the next 10 years were classed as at “raised risk”, and those with less than a 10% chance, at “low risk”.

Of the 949,973 adults included in the study, 12% had existing CVD, 32% were classed as being at raised risk of CVD and 56% at low risk. A total of 4,017 of these participants were diagnosed with COVID-19 between 12 March and 29 September.

Among those with COVID-19, 576 died (giving an overall death rate of 219 per 1,000), 159 were admitted to the ICU admission (60 per 1,000) and 1,091 were hospitalised (414 per 1,000).

The researchers found that the likelihood of COVID-19 infection was similar among individuals with raised and low cardiovascular risk (4.9 cases per 1,000 vs 4.5 cases per 1,000, respectively).

However, rates of death (311 per 1,000 vs 24 per 1,000), ICU admission (97 per 1,000 vs 36 per 1,000) and hospitalization (607 per 1,000 vs 169 per 1,000) were substantially higher in those with raised cardiovascular risk.

These findings suggest that, compared to the low cardiovascular risk group, those at raised cardiovascular risk were six times as likely to die from COVID-19, and had three times the risk of being hospitalised with COVID-19 or admitted to the ICU.

Dr Charlotte Warren-Gash, from LSHTM senior author of the study, said: “It is important that people at greater risk of developing cardiovascular disease should be encouraged to take up COVID-19 vaccines and boosters. Because many of the cardiovascular risk factors associated with more severe consequences from COVID-19 are potentially modifiable, clinicians and policy makers should consider that strategies which improve cardiovascular health may also improve outcomes for people following COVID-19.”

The researchers acknowledge the limitations of this study, including that it is an observational study so no firm conclusions can be drawn about cause and effect, and they cannot rule out the possibility that other unmeasured factors may have affected the results.  

The researchers are currently updating their findings in a dataset of over 6 million individuals which will then be submitted for peer-review publication.

***This research is not yet peer-reviewed***

Publication

Jennifer Davidson. The effect of cardiovascular risk on severe COVID-19 outcomes in England during 2020: a cohort study. Abstract being presented at ECCMID conference.