Abstract 13640: Effects of Influenza Vaccine on Mortality and Cardiovascular Outcomes Ii Patients With Cardiovascular Disease: A Systematic Review and Meta-analysis

Abstract

Introduction: Influenza infection is associated with increased morbidity and mortality in patients with cardiovascular disease (CVD). We assessed the effects of influenza vaccine on mortality and cardiovascular outcomes in patients with CVD. Hypothesis: Influenza vaccination in those with CVD is associated with a reduction in mortality and major adverse cardiovascular events (MACE). Methods: We searched PubMed, EMBASE, and Cochrane library through January 2020 for randomized-controlled trials (RCTs) and observational studies assessing effects of influenza vaccine on mortality and cardiovascular outcomes in patients with CVD. Estimates were reported as random effects risk ratios (RR) with 95% confidence intervals (CI). Analyses were stratified by study design into RCT and observational studies. Results: Overall, 16 studies (n=237,058) encompassing 4 RCTs (n=1,667) and 12 observational studies (n=235,391) were included. The mean age was 69.2±7.01; 36.6% were female, 65.1% had hypertension, 31.1% had diabetes, and 23.4% were smokers. The median follow-up duration was 19.5 (IQR, 12, 43.3) months. Influenza vaccine was associated with a lower risk of all-cause mortality (RR, 0.72 [95% CI, 0.59-0.89], p<0.001) ( Figure 1A ), cardiovascular mortality (RR, 0.82 [95% CI, 0.80-0.84], p<0.001), and MACE (RR, 0.87 [95% CI, 0.80-0.94], p<0.001) ( Figure 1B ), though the association with myocardial infarction was not statistically significant (RR, 0.73 [95% CI, 0.50-1.07]; p=0.10). These finding were consistent across randomized and observational studies. Conclusions: This meta-analysis suggests that both randomized and observational data support the use of influenza vaccine in adults with CVD to reduce mortality and MACE events. Efforts to improve utilization of influenza vaccine in this population should continue to reap survival benefits.