Influence of influenza vaccination on recurrent hospitalization in patients with heart failure

Abstract

The current study aimed to evaluate the influence of regular annual influenza vaccinations on cardiovascular (CV) death and heart failure-related hospitalizations (HFrH) in stable outpatients with heart failure with reduced ejection fraction. The Turkish research team-HF (TREAT-HF) is a network undertaking multicenter, observational cohort studies in HF. This study is a subgroup analysis of TREAT-HF outpatient cohorts who completed a questionnaire on influenza vaccination status and for whom follow-up data were available. A total of 656 patients with available follow-up data for CV death and HFrH including recurrent hospitalization were included in the study. Patients were classified into two groups: those who received regular influenza vaccination (40 %) and those who did not receive vaccination. During a mean follow-up of 15 +/- 6 months, 113 (18 %) patients had CV death and 471 (72 %) patients had at least one HFrH. The CV death rate was similar in both groups of patients (16 vs. 19 %, p = 0.37), whereas, HFrH and recurrent HFrH were significantly less frequently encountered in patients who received regular influenza vaccination than in those who did not receive vaccination (43 vs. 92 % and 16 vs. 66 %, p < 0.001, respectively). In a multivariate Cox proportional hazards model - in addition to a few clinical factors - vaccination status (HR = 0.30, 95 % CI = 0.17-0.51, p < 0.001) and graduation from university (HR = 0.35, 95 % CI = 0.17-0.72, p = 0.004) remained independently associated with the risk of recurrent HFrH. Regular influenza vaccination does not influence CV deaths; however, it decreases HFrH including recurrent episodes of HFrH in outpatients with heart failure with reduced ejection fraction.