Influenza is a viral infection of the respiratory system characterized by fever, chills, muscle aches, runny nose, and congestion. Cardiovascular complications, mainly heart failure (HF), are common among patients with influenza, but the temporal association between influenza activity and heart failure is not clear. This study aims to discover the temporal association between influenza activity and the risk of HF and myocardial infarction (MI)-related hospitalizations.

This population-based study included a total of 451,588 adults, of which 7,862 patients were included in the analysis. The patients were exposed to influenza activity and were hospitalized for HF or MI. The primary outcome of the study was the monthly frequency of MI and HF hospitalizations.

Of 7,862 patients in the study, 4,321 were hospitalized for HF and 3,541 for MI. The findings suggested a 5% absolute monthly increase in influenza activity to be associated with a 24% increase in HF hospitalization rates. However, significant associations were found between influenza activity and MI hospitalizations. It was also found that approximately 19% of HF hospitalizations could attribute to influenza.

The research concluded that influenza activity was temporally associated with an increased risk of HF hospitalizations, but not with MI hospitalizations.