Influenza vaccination in patients with heart failure A protocol for meta-analysis of randomized controlled trials

Background: Heart failure is a major public health problem. Although there have been significant advances in the management of heart failure, the mortality and morbidity in heart failure patients remain high. Heart failure patients are susceptible to influenza-related complications including acute heart failure exacerbations and secondary infections such as pneumonia, both of which lead to significant morbidity and mortality. An earlier meta-analysis of observational cohort studies reported that influenza vaccination was associated with reduced risk of mortality in heart failure patients. Although there are no published randomized controlled trials (RCTs) on the effect of influenza vaccination on clinical outcomes in heart failure patients, there are several on-going RCTs examining the effect in these patients. We aim to conduct a meta-analysis of RCTs to assess the efficacy and safety of influenza vaccination in heart failure patients. Methods: This meta-analysis will include RCTs examining the effect of influenza vaccination in heart failure patients. Information of studies will be collected from electronic databases. The primary outcome of interest will be cardiovascular death. The secondary outcomes of interest will be all-cause death, nonfatal myocardial infarction, nonfatal stroke, hospitalization for heart failure, and hospitalization for any cause. Discussion: This meta-analysis will evaluate the efficacy and safety of influenza vaccination in heart failure patients, providing evidence to the use of influenza vaccine in these patients. Systematic review registration: INPLASY202210115.