Covid-19: First wave increased heart attack, stroke risk up to three years

A recent study has revealed that Covid-19 infections raised the risk of heart attacks, strokes, and death for up to three years in unvaccinated individuals, especially during the pandemic’s early phase when the original SARS-CoV-2 strain was prevalent.
The research, backed by the National Institutes of Health (NIH), the apex medical research agency of the US, which included people with and without pre-existing heart conditions, reaffirmed earlier findings linking Covid-19 to a higher likelihood of cardiovascular problems.
However, it is the first to suggest that these risks could extend up to three years after the initial infection, particularly for those infected during the pandemic’s first wave.
WHAT DOES THE STUDY SAY?
The study found that people who contracted Covid-19 early on faced double the risk of cardiovascular events compared to those who never had the virus. Severe Covid-19 cases were linked to nearly four times the risk.
These findings were recently published in Arteriosclerosis, Thrombosis, and Vascular Biology.

The study found that people who contracted Covid-19 early on faced double the risk of cardiovascular events compared to those who never had the virus. (Photo: Getty Images)

Dr David Goff, director of the Division of Cardiovascular Sciences at NIH’s National Heart, Lung, and Blood Institute (NHLBI), noted that the study offers crucial insights into the prolonged cardiovascular effects of Covid-19.
He mentioned that further research is necessary to validate the findings, which could aid in developing strategies to prevent heart disease in those who had severe Covid-19 cases.
One novel aspect of the research is its focus on the potential genetic link between blood type and the increased risk of heart attack or stroke in severe Covid-19 patients.
The study found that people with A, B, or AB blood types were more than twice as likely to suffer from heart attacks or strokes after hospitalisation for Covid-19, whereas those with O blood types appeared to be at lower risk.
The analysis drew on data from 10,000 participants in the UK Biobank, a comprehensive biomedical database of European patients aged 40 to 69.
Of these, 8,000 tested positive for Covid-19, while 2,000 were hospitalised due to severe illness between February and December 2020, before vaccines became available.
The researchers compared these groups with nearly 2,18,000 individuals who never contracted the virus. They monitored the participants over nearly three years to track occurrences of heart attacks, strokes, or deaths.
Adjusting for those with prior heart disease, about 11% of both groups, the researchers found that the risk of cardiovascular events was twice as high for Covid-19 patients and four times higher for those with severe illness.

People with A, B, or AB blood types were more than twice as likely to suffer from heart attacks or strokes after hospitalisation for Covid-19. (Photo: Getty Images)

The elevated risk remained throughout the three-year follow-up, at times equating to or surpassing known risk factors such as type 2 diabetes.
The study’s lead author, Hooman Allayee from the University of Southern California Keck School of Medicine, highlighted the global implications of these findings, given that over a billion people have already been infected with Covid-19.
“The question now is whether or not severe Covid-19 should be considered another risk factor for cardiovascular disease, much like type 2 diabetes or peripheral artery disease, where treatment focused on cardiovascular disease prevention may be valuable,” he said.
Allayee also pointed out that these results mainly apply to those infected during the early pandemic stages, and it remains uncertain if recent severe Covid-19 cases (since 2021) carry the same long-term cardiovascular risks.
LIMITATIONS OF THE STUDY
However, the researchers acknowledged that the study had limitations, as it only included data from the predominantly white UK Biobank.
Further research is needed to determine if these findings hold true in more diverse populations. Since the participants were unvaccinated, future studies will need to assess whether vaccines impact cardiovascular risk.
More research is also required to clarify the connection between blood type and Covid-19, as the exact mechanism behind this relationship remains unclear, the authors said.