Infections can be a trigger for heart attack or stroke

WEDNESDAY, November 28, 2018 (American Heart Association) – Diabetes, high blood pressure and high cholesterol are well-known risk factors for cardiovascular disease. But what about getting sick? Can detecting a type of virus increase the risk of stroke or heart attack?

A new study suggests that it could.

Researchers have linked infections such as pneumonia and urinary tract infections to an increased risk of a coronary event, such as a heart attack or stroke, over the next three months.

In the study published recently in the Journal of the American Heart Association, researchers examined a patient registry followed over several years in four US cities. They examined 1,312 patients who had a heart attack or other type of coronary event, and 727 other patients who had ischemic stroke, of the type caused by a blood clot.

About 37% of patients with heart disease had contracted an infection in the previous three months. Among patients with stroke, it was almost 30%.

Infections significantly increased the risk of having a heart attack or stroke compared to a year or two earlier in the same group of patients, and these probabilities were highest in the first two weeks after infection.

Infections usually cause an inflammatory reaction in the body, said Dr. Kamakshi Lakshminarayan, neurologist and senior author of the study.

The body triggers its production of white blood cells to help prevent an infection, but this process also increases the stickiness of cells called platelets, she said. This promotes the formation of clots that could block the flow of blood to the heart or brain.

"The infection appears to be the trigger for the change in blood balance and our vulnerability to thrombosis or clot formation," said Lakshminarayan, badociate professor of epidemiology. at the Faculty of Medicine at the University of Minnesota. "This causes a blockage of blood vessels and increases the risk of serious events such as a heart attack or stroke."

The study raises questions as to whether patients hospitalized for infections should also start receiving treatment to protect them from heart disease and stroke. Additional research could provide these answers, Lakshminarayan said.

The urinary tract infection, or urinary tract infection, was the type of infection most often reported in the study, followed by pneumonia and other respiratory infections. Skin and blood infections have also been reported.

The study included patients treated for infections during their hospitalization and those receiving outpatient care. Both groups were more likely to have a cardiovascular event within three months of infection, but this badociation appeared to be stronger in the inpatient group.

In fact, infections requiring hospitalization are probably more serious in the beginning, said Juan Badimon, professor of medicine and director of the research unit on atherothrombosis at the Mount Sinai Cardiovascular Institute. School of Medicine in New York.

"And if the infection is so severe, we can badume that a stronger inflammatory response will result in a higher cardiovascular risk," said Badimon, who did not participate in the research, but said co-authored an editorial that accompanied the study.

He described the badociation between cardiovascular events and all types of infections, not just respiratory, a "new discovery". But he would have liked to see researchers dig deeper and note whether the source of the infection – viral or bacterial – had played a role in the increased risk of heart attacks and strokes.

Badimon hopes the results will encourage the public to make sure their vaccines are up to date, especially during the influenza season.

Lakshminarayan agreed.

"One of the most important things to remember is that we need to prevent these infections whenever possible," she said. "This means flu vaccines and vaccines against pneumonia, especially for the elderly."