Flu May Trigger Heart Attacks Say Researchers Who Urge Shots
A review of 39 studies conducted from 1932 to 2008 found consistent links between influenza and major heart attacks, bolstering previous observations that the heart can be damaged in patients with influenza, according to the report in Lancet Infectious Diseases.
People at risk for heart attacks, including those with diabetes and cardiovascular disease, should get vaccinated against influenza, said the researchers led by Andrew Hayward from University College Londons Center for Infectious Disease Epidemiology. While the immunization is recommended for people with chronic conditions, fewer than half of them in the U.K. were vaccinated last year, the researchers said.
There is “consistent evidence” that influenza triggers acute heart attacks and death from cardiovascular disease, the researchers concluded. There is also some evidence that influenza vaccines may reduce the danger, particularly in patients with existing heart disease, they said.
The number of people expected to develop the flu is higher than normal this year as a novel swine flu circles the globe.
Rising Cases
The pandemic has spiked over the last two weeks in the U.S. and U.K. as students returned to tightly packed classrooms. Health officials are racing to begin vaccination campaigns to curtail the outbreak, which in the U.S. is already higher than the peak rate in two of the last three flu seasons, according to the Atlanta-based Centers for Disease Control and Prevention.
Influenza may increase levels of inflammation in the body, raising the risk that fatty plaque in the arteries breaks off to form a heart attack-causing clot, the researchers said.
“We believe that influenza vaccination should be encouraged wherever indicated, especially in people with existing cardiovascular disease,” the researchers said. More evidence is needed to determine the effectiveness of vaccines to reduce heart risks in patients without existing disease, they said.