Flu Shot May Help Prevent Hospitalization, Dementia in Heart Failure Patients

Patients with heart failure (HF) should know that getting a flu shot could lower their risk of being hospitalized and developing dementia.

Findings from 2 separate studies presented at the European Society of Cardiology’s Heart Failure 2016 Congress suggest that influenza vaccination could protect HF patients from hospital admission and dementia, although both studies stopped short of proving cause and effect.

The first study on flu and hospitalization examined the electronic health records of 59,202 patients in the United Kingdom with heart failure between 1990 and 2013. All study participants went at least 1 year with a flu shot and 1 year without one. The researchers compared patients’ health during a vaccinated year with it during an unvaccinated year, irrespective of the order.

They found that HF patients had a 30% lower risk of cardiovascular (CV) hospitalization during a vaccinated year compared with an unvaccinated one. Likewise, vaccinated HF patients had a 16% lower risk of respiratory infection-related hospitalization and a 4% lower risk of all-cause hospitalization.

Lead study author Kazem Rahimi believes influenza infection can act as a trigger, “…and if that trigger effect is controlled by vaccination, it’s likely to reduce admission to the hospital,” he toldHeartwire.

The study “provides the most compelling evidence to date for the protective effect of influenza vaccination on hospital admissions,” Rahimi said.

Meanwhile, the second study on flu and dementia examined data from the Taiwan Longitudinal Health Insurance Database that held 20,509 study participants older than 60 years who received a diagnosis of congestive HF between 2000 and 2012. During the study period, 10,797 participants received at least 1 flu shot, while 9712 participants did not.

The researchers found that all vaccinated patients with congestive HF had a significantly reduced risk for developing dementia, compared with those who were unvaccinated. The observed risk was even more pronounced among patients older than 70 years.

Male participants also had a significantly lower dementia risk than their female counterparts.

Lead study author Ju-Chi Liu hypothesized that flu shots may lower the risk of infection, which in turn may reduce the risk of the inflammation associated with injury to brain cells. Brain cell injury may contribute to the development of dementia, “especially in those with [HF], who have been shown to have impaired circulatory status in the brain,” Liu said.

Although causality wasn’t established in either study, clinicians can communicate the findings to all patients as part of their vaccination awareness efforts and overall preventative care strategies.