High cholesterol and blood pressure are known risk factors for heart attack.
However, a new study shows another important risk factor has been under the radar the flu.
Researchers studied autopsy reports from St. Petersburg, Russia they used this population because only a minority of residents there get a flu vaccine or take anti-cholesterol drugs.
They found during peak flu season the chance of dying from a heart attack or heart disease went up by a third.
Researchers say the flu can increase inflammation in the body which may lead to a heart attack.
People with chronic medical conditions like heart disease are already considered "high-risk" by the CDC and should get a flu shot every year.
It could prove to be a medical breakthrough in the fight against diabetes.