New study on viral consequences Flu and coronavirus multiply the risk of heart attack and stroke
Viral infections can put the heart at risk: Researchers show that influenza and coronaviruses significantly increase the risk of heart attack and stroke shortly after infection. Other viruses such as HIV or hepatitis C also increase the risk of cardiovascular disease in the long term.
01.11.2025, 06:10
01.11.2025, 07:10
SDA
According to researchers, flu viruses and coronaviruses significantly increase the risk of acute cardiovascular disease shortly after infection. The risk of a heart attack or stroke increases four to fivefold after an infection.
In the case of Sars-Cov-2, the risk of a heart attack or stroke increases approximately threefold, as a research team led by Kosuke Kawai from the University of California in Los Angeles reported in a review study in the "Journal of the American Heart Association". Other viruses lead to lower but longer-term risks.
It is now known that human papillomaviruses, hepatitis B viruses and other viruses can cause cancer. "However, the link between viral infections and other non-communicable diseases such as cardiovascular disease is less well understood," Kawai is quoted as saying in a statement from the American Heart Association.
He and his colleagues found more than 52,000 studies on the link between viral infections and cardiovascular disease from 1997 to 2024 in several medical databases. Of these, they selected 155 that met their quality requirements and could be made comparable using statistical methods.
Reaction of the immune system releases substances
The analysis showed the clearest correlation between infections with Sars-Cov-2 and influenza. The risk of suffering a stroke is five times higher in the four weeks following the onset of influenza than in people without influenza. In the same period, the risk of suffering a heart attack is four times higher. Within four weeks of a Sars-Cov-2 infection, the risk of heart attack is 3.1 times higher and the risk of stroke is 2.9 times higher. The researchers explain the increased risk by the fact that the natural reaction of the immune system to viral infections releases substances that trigger inflammation and promote blood clotting, which impairs the cardiovascular system.
The analysis also revealed that infection with the human immunodeficiency virus (HIV), which causes AIDS, increases the risk of heart attack by 60 percent and the risk of stroke by 45 percent. The viral disease hepatitis C increases the risk of heart attack by 27 percent and the risk of stroke by 23 percent. In the case of varicella zoster virus (shingles), the risk increase is slightly lower (heart attack: 12 percent, stroke: 18 percent). All these figures also relate to the period four weeks after infection. "However, the risks associated with these three viruses are still clinically relevant, especially because they persist over a long period of time; in addition, shingles affects around one in three people over the course of their lives," emphasized Kawai.
Flu vaccination can protect against more than just the flu
The authors of the study advocate increased vaccination against viruses that can trigger cardiovascular diseases. "Prevention is particularly important for adults who already suffer from cardiovascular disease or risk factors for cardiovascular disease," said Kawai. In the study, the scientists refer to a review from 2022: according to this, a flu vaccination reduced the risk of suffering a serious cardiovascular disease by 34 percent.
The current study also showed an increased risk of cardiovascular disease with other viruses, such as herpes simplex virus 1, hepatitis A virus, human papilloma virus and the viruses that cause dengue fever and chikungunya fever. However, the results were less conclusive than for the viruses mentioned above. The authors of the study call for further research into the link with cardiovascular disease, as these viral infections are widespread globally.
