Influenza vaccination in patients with heart failure: a systematic review and meta-analysis of observational studies

Abstract

<jats:sec><jats:title>Objective</jats:title><jats:p>Despite the progression of treatments over decades, heart failure (HF) is a disease with high morbidity, mortality and economic burden. Influenza infection is an important trigger for cardiovascular (CV) events, including HF. Influenza vaccination has been seen to reduce the risk of CV mortality in patients with coronary disease, but the effect in patients with HF is still unclear. Therefore, we conducted a systematic review to evaluate the effect of influenza vaccination in the morbimortality of patients with HF.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>MEDLINE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Health Technology Assessment and PsycINFO databases (December 2018) were searched for longitudinal studies evaluating influenza vaccination compared with a non-vaccination control group in patients with HF. The risk of bias was assessed according to the ROBINS-I tool. We performed a random-effects meta-analysis to estimate the pooled HRs with 95% CIs, and heterogeneity was evaluated using the I<jats:sup>2</jats:sup> statistics.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Six cohort studies evaluating 179 158 patients with HF were included in the meta-analysis. Influenza vaccination was associated with a lower risk of all-cause mortality (HR=0.83; 95% CI 0.76 to 0.91; I<jats:sup>2</jats:sup>=75%). The effect of the influenza vaccination was not statistically significant in a pooled analysis of CV mortality (HR=0.92, 95% CI 0.73 to 1.15; 2 studies) and of all-cause hospitalisations (HR=1.01, 95% CI 0.92 to 1.11; 2 studies). The majority of outcomes in the included studies had a serious risk of bias and almost all evaluated outcomes had very low Grading of Recommendation, Assessment, Development and Evaluation (GRADE) evidence.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>Influenza vaccination was associated with a significant decrease in all-cause mortality risk in patients with HF.</jats:p></jats:sec>

Satisfaction of Patients with Nonvitamin K Anticoagulants Compared to Vitamin K Antagonists: a Systematic Review and Meta-analysis

“…32 To reduce the effect of potential confounding variables resulting from differences in the participants' characteristics of observational studies, whenever possible we used propensity-matched scores. 33,34 We performed a sensitivity analysis by excluding observational studies at a high overall risk of bias from the analysis. We assessed publication bias through funnel plot inspection and statistical methods, providing that a sufficient number of studies were included.…”

Effects of influenza vaccination on the risk of cardiovascular and respiratory diseases and all-cause mortality

“…The results on composite and specific cardiovascular adverse outcomes are consistent with two meta-analyses of RCTs that demonstrate significant association between influenza vaccination and a lower risk of major adverse cardiovascular events ( Clar et al, 2015 ; Udell et al, 2013 ), with a more pronounced effect in high-risk patients with recent coronary artery disease ( Udell et al, 2013 ). In patients with heart failure, influenza vaccination in the previous year has been shown to reduce the risk of mortality and hospitalization ( Fukuta et al, 2019 ; Poudel et al, 2019 ; Rodrigues et al, 2020 ). Influenza vaccination is also reported to reduce the risk of stroke ( Lee et al, 2017 ; Smeeth et al, 2004 ; Tsivgoulis et al, 2018 ).…”

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