Serious cardiovascular events risk increased with the flu, US research finds
Coming down with the flu increases the risk of serious or fatal cardiovascular events, especially for patients predisposed to the condition. While getting the influenza vaccine can reduce this risk, influenza (flu) vaccination rates continue to remain low despite higher rates of death and complications from influenza.
According to specialists at Houston Methodist medical centre in Texas, the flu vaccination rate for American adults who are less than 65 years of age and have heart disease is less than 50%; the same rate is 80% in older adults with heart disease.
“[…] younger Americans with high-risk conditions have not gotten the same memo that their older counterparts have received about the importance of getting the influenza vaccine,” said Dr. Priyanka Bhugra, internal medicine specialist at Houston Methodist. “That’s dangerous, considering people with heart conditions are particularly vulnerable to influenza-related heart complications, whether they’ve reached retirement age or not.”
Recent research can attest: patients are found to be six times more likely to experience a heart attack the week after influenza infection than they are at any point during the year prior or the year after the infection.
One study looking at 90,000 lab-confirmed influenza infections showed a strikingly similar rate of 11.7% experiencing an acute cardiovascular event. One in eight patients, or 12.5%, admitted to the hospital with influenza experienced a cardiovascular event, with 31% of those requiring intensive care and 7% dying because of the event, another study found.
The inflammation resulting from a flu is known to cause “visible effects” such as swelling, tenderness, pain, weakness, and sometimes redness and increased temperature of the joints, muscles, and lymph nodes. What is less obvious is that the increased activity can also lead to blood clots, elevated blood pressure and even swelling or scarring within the heart resulting in heart attacks or strokes, respectively.
Non-cardiac complications from the viral illness, including pneumonia and respiratory failure, can additionally exacerbate heart failure symptoms or heart arrhythmia such that overwhelms an already weakened heart muscle.
As a result of the demonstrated benefits conferred by influenza vaccination and the risks posed by flu infection among those with cardiovascular disease, the CDC and numerous other international societies strongly recommend annual influenza vaccination in patients with cardiovascular disease.
Studies have shown that the influenza vaccine was effective at protecting the general population and the most vulnerable age groups (over 65 and under 2) from severe cases of the flu, and is equally protective against cardiovascular mortality, especially among the high-risk population – vaccination was associated with a lower risk of cardiovascular events (2.9% vs 4.7%) if the patient got the flu; vaccination was also associated with considerably better outcomes.
Clinicians are advised to ensure high rates of influenza vaccination, especially in those with underlying chronic conditions, to protect against acute cardiovascular events associated with influenza.
Read: Antibodies against COVID-19 vary with vaccination vs natural infection
