Influenza vaccination may lead to reduction of hospitalization for heart failure in elderly patients with chronic obstructive pulmonary disease

Background: Vaccination against influenza may decrease the risk of an acute cardiovascular event in the elderly. The purpose of this study was to test the hypothesis that influenza vaccination could reduce hospitalizations for heart failure (HF) in patients with chronic obstructive pulmonary disease (COPD). Methods: Using Taiwan National Health Insurance Research Dataset (NHIRD) 2000 to 2007, this cohort study comprised patients with a recorded diagnosis of COPD (n = 25,609) between January 1, 2000 and December 31, 2007. Each patient was followed up until the end of 2007. Cox proportional hazard regression analysis was used to evaluate the HF-free survival rates after adjusting for known confounding factors. Results: We found that patients with COPD but no history of a cardiovascular event had a lower risk of hospitalization for HF after receiving influenza vaccination. After adjusting for potential confounders, there was a possible decrease in HF admission for the vaccinated group [hazard ratio (HR), 0.44, 95% confidence interval (CI), 0.35-0.55]. When stratified in terms of the patients' ages, the adjusted HR for hospitalization due to HF was 0.36 (95% CI, 0.28-0.46) for vaccinated patients over 64 years of age; however, the adjusted HR for HF in patients under 55 years of age who had received vaccination was not significant. Conclusion: Our data show that there was a lower rate of hospitalization from HF in patients with COPD receiving influenza vaccination, but only in patients older than 65 years.