Flu shot may protect against atrial fibrillation (irregular heart beat)

A new study has found another possible benefit from the flu shot – protection against atrial fibrillation (irregular heart beat), which is a risk factor for stroke. The study included 57,000 people from Taiwan. The researchers found a significant link between the flu shot and new cases of atrial fibrillation, compared to those who did not receive the flu shot. Atrial fibrillation is associated with a five times greater risk of stroke.

Individuals who did not receive the flu shot and developed the flu were 18 times more likely to develop atrial fibrillation, compared to those who did not get vaccinated. Furthermore, the association was still seen among different groups of people.
Lead investigator Dr. Tze-Fan Chao said, “According to the findings presented here, the possibility of AF should be kept in mind when patients with influenza infection complain of palpitations or experience ischemic stroke. Influenza vaccination should be encouraged for patients, especially those who have a high risk of atrial fibrillation, to try to prevent the occurrence of atrial fibrillation and subsequent stroke. However, a further prospective study is necessary to confirm our findings.”

In an accompanying editorial, cardiologists from Northwestern University added that the flu shot has broader health implications, noting, “The results of this study beg the question as to whether the acute treatment of the influenza infection itself, or addressing the inflammatory response associated with infection, may help prevent secondary episodes of AF. Beyond the prospective trial mentioned by the authors, we look forward to future studies into these and other areas that may help confirm and validate the observed findings.”