Influenza vaccination: a 'shot' at INVESTing in cardiovascular health

Association of post-vaccination adverse reactions after influenza vaccine with mortality and cardiopulmonary outcomes in patients with high-risk cardiovascular disease: the INVESTED trial

AIMS

Influenza vaccination is associated with reduced cardiopulmonary morbidity and mortality among patients with heart failure or recent myocardial infarction. The immune response to vaccination frequently results in mild adverse reactions (AR), which leads to vaccine hesitancy. This post hoc analysis explored the association between vaccine-related AR and morbidity and mortality in patients with high-risk cardiovascular disease.

METHODS AND RESULTS

The INVESTED trial randomized 5260 patients with recent heart failure hospitalization or acute myocardial infarction to high-dose trivalent or standard-dose quadrivalent inactivated influenza vaccine. We examined the association between vaccine-related AR and adverse clinical outcomes across both treatment groups in propensity-adjusted models. Among 5210 participants with available information on post-vaccination symptoms, 1968 participants (37.8%) experienced a vaccine-related AR. Compared to those without AR, post-vaccination AR, most commonly injection site pain (60.3%), were associated with lower risk for the composite of all-cause death or cardiopulmonary hospitalization (hazard ratio [HR] 0.83, 95% confidence interval [CI] 0.75-0.92, p < 0.001), cardiopulmonary hospitalizations (HR 0.85 [95% CI 0.76-0.95], p = 0.003), all-cause death (HR 0.77 [95% CI 0.62-0.96], p = 0.02), cardiovascular hospitalizations (HR 0.88 [95% CI 0.78-0.99], p = 0.03) and non-cardiopulmonary hospitalizations (HR 0.80 [95% CI 0.69-0.92], p = 0.003). While mild (76.4%) and moderate (20.6%) AR were most common and together associated with lower risk for the primary outcome (HR 0.81 [95% CI 0.74-0.90], p < 0.001), severe AR (2.9%) were related to increased risk (HR 1.68 [95% CI 1.17-2.42], p = 0.005).

CONCLUSION

Mild to moderate post-vaccination reactions after influenza vaccine were associated with reduced risk of cardiopulmonary hospitalizations and all-cause mortality in patients with high-risk cardiovascular disease, while severe reactions may indicate increased risk. Mild to moderate AR to influenza vaccination may be a marker of immune response and should not deter future vaccinations.

Influenza Vaccination for Cardiovascular Prevention: Further Insights from the IAMI Trial and an Updated Meta-analysis

PURPOSE OF REVIEW

Influenza infection is a significant, well-established cause of cardiovascular disease (CVD) and CV mortality. Influenza vaccination has been shown to reduce major adverse cardiovascular events (MACE) and CV mortality. Therefore, major society guidelines have given a strong recommendation for its use in patients with established CVD or high risk for CVD. Nevertheless, influenza vaccination remains underutilized. Historically, influenza vaccination is administered to stable outpatients. Until recently, the safety and efficacy of influenza vaccination among patients with acute myocardial infarction (MI) had not been established.

RECENT FINDINGS

The recently published Influenza Vaccination after Myocardial Infarction (IAMI) trial showed that influenza vaccination within 72 h of hospitalization for MI led to a significant 28% reduction in MACE and a 41% reduction in CV mortality, without any excess in serious adverse events. Additionally, we newly performed an updated meta-analysis of randomized clinical trials (RCTs) including IAMI and the recent Influenza Vaccine to Prevent Adverse Vascular Events (IVVE) trial. In pooled analysis of 8 RCTs with a total of 14,420 patients, influenza vaccine, as compared with control/placebo, was associated with significantly lower risk of MACE at follow-up [RR 0.75 (95%CI 0.57-0.97), I2 56%]. The recent IAMI trial showed that influenza vaccination in patients with recent MI is safe and efficacious at reducing CV morbidity and mortality. Our updated meta-analysis confirms a 25% reduction in MACE. The influenza vaccine should be strongly encouraged in all patients with CVD and incorporated as an essential facet of post-MI care and secondary CVD prevention.

Moving the Needle on Atherosclerotic Cardiovascular Disease and Heart Failure with Influenza Vaccination

PURPOSE OF REVIEW

The interplay between viral respiratory infections and cardiovascular disease has been most comprehensively researched using seasonal and pandemic influenza viruses as case studies. Here, we summarize the latest international observational research and clinical trials that examined the association between influenza, influenza vaccines, and cardiovascular disease, while contextualizing their findings within those of landmark studies.

RECENT FINDINGS

Most recent observational literature found that one in eight adults hospitalized with laboratory-confirmed influenza infection experienced an acute cardiovascular event. The latest meta-analysis of the cardioprotective effects of influenza vaccine found a 25% reduced risk of all-cause death. There are four large cardiovascular outcome trials assessing the cardioprotective effects of different influenza vaccine strategies. Among these, the INVESTED study showed there is no significant difference between the high-dose trivalent and standard-dose quadrivalent influenza vaccines in reducing all-cause mortality or cardiopulmonary hospitalizations in a high-risk patient group with pre-existing cardiovascular disease. Persons with cardiovascular disease represent a high priority group for viral vaccines; hence, using robust evidence to increase vaccine confidence among patients and practitioners is integral as we prepare for a possible influenza resurgence in the coming years.

Influenza Vaccination for the Prevention of Cardiovascular Disease in the Americas: Consensus document of the Inter-American Society of Cardiology and the Word Heart Federation

Background

Cardiovascular mortality is decreasing but remains the leading cause of death world-wide. Respiratory infections such as influenza significantly contribute to morbidity and mortality in patients with cardiovascular disease. Despite of proven benefits, influenza vaccination is not fully implemented, especially in Latin America.

Objective

The aim was to develop a regional consensus with recommendations regarding influenza vaccination and cardiovascular disease.

Methods

A multidisciplinary team composed by experts in the management and prevention of cardiovascular disease from the Americas, convened by the Inter-American Society of Cardiology (IASC) and the World Heart Federation (WHF), participated in the process and the formulation of statements. The modified RAND/UCLA methodology was used. This document was supported by a grant from the WHF.

Results

An extensive literature search was divided into seven questions, and a total of 23 conclusions and 29 recommendations were achieved. There was no disagreement among experts in the conclusions or recommendations.

Conclusions

There is a strong correlation between influenza and cardiovascular events. Influenza vaccination is not only safe and a proven strategy to reduce cardiovascular events, but it is also cost saving. We found several barriers for its global implementation and potential strategies to overcome them.