Flu Virus Can Raise Risk of Heart Attack Among Heart Patients

The common flu virus may raise the risk of dying from heart disease by increasing the likelihood for heart patients to suffer a heart attack. Those who have diabetes or other risk factors may also be at greater risk.

Results of an analysis conducted by a group of British researchers of 39 previous studies of heart patients conducted between 1932 and 2008 showed an increase in the number of deaths from heart disease, as well as the occurrence of more heart attacks during flu season. In fact, the increased death rate averaged from 35 percent to 50 percent. The report was recently published in the journal Lancet.

Although currently only about one-third of Americans who suffer from heart disease receive flu vaccines, experts are urging all heart patients to get vaccinated against regular flu as well as swine flu. With more flu virus expected to be circulating this flu season, the possibility of experiencing flu-related medical issues is greater among those having heart-related problems. Dr. Ralph Brindis, vice president of the American College of Cardiology, says, “If we can convince cardiac patients to get a flu vaccine, that could ultimately save lives.”

Because flu viruses cause inflammation in the body, and most commonly in the lungs, heart patients who contract the flu become more vulnerable to complications including pneumonia and other types of infection. In addition, flu viruses can cause swelling in the heart or coronary arteries, potentially triggering the breaking off of dangerous clots that lead to a heart attack.

According to study author Andrew Hayward, a senior lecturer in infectious disease epidemiology at the University College London Centre for Infectious Disease Epidemiology, “We know influenza vaccine is effective in preventing influenza and therefore in theory, ought to be effective in preventing the complications of influenza.” Hayward pointed out that two of the studies in the analysis indicated that heart patients who received a flu vaccine suffered fewer heart attacks than those who did not. He also acknowledged that “Influenza may be bringing forward an event that might have happened anyway,” and further explained that some evidence suggests that heart attacks peak when the flu virus does.

It remains unclear as to whether the new study results can be applied to people who are otherwise healthy, with no history of heart disease. However, the researchers noted that flu viruses could potentially trigger heart attacks among people having risk factors such as high blood pressure or those who are overweight. Diabetes is another condition that may put individuals at greater risk.

The researchers concluded, “We believe influenza vaccination should be encouraged wherever indicated, especially in those people with existing cardiovascular disease. Further evidence is needed on the effectiveness of influenza vaccines to reduce the risk of cardiac events in people without established vascular disease.”

The Advisory Committee on Immunization Practices (ACIP), selected by the Secretary of the U. S. Department of Health and Human Services, recommends annual flu vaccines for all people who are at high risk of having serious seasonal flu-related complications or people who live with or care for those at high risk for serious seasonal flu-related complications. According to the American Heart Association, about 36,000 people die each year from flu, while over 200,000 are hospitalized due to complications arising from it including bacterial pneumonia, dehydration and worsening of chronic medical conditions, such as congestive heart failure, asthma or diabetes.