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

[Vaccination and cardiovascular diseases]

Respiratory tract infections with influenza, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and respiratory syncytial (RS) viruses and pneumococci as well as endogenous reactivation of varicella zoster viruses presenting as herpes zoster, are associated with adverse cardiovascular outcomes, such as myocardial infarction or hospitalization for heart failure. Effective prevention of these events, particularly through influenza and pneumococcal vaccination, is well established and cost-effective. Despite guideline recommendations to vaccinate older patients and people at risk, vaccination rates in these population groups remain suboptimal and below average in international comparison. This article sheds light on the association of vaccine preventable diseases with cardiovascular complications and demonstrates the protective effect of the respective vaccinations. Additionally, recommendations on the practical approach to vaccinating high-risk patients are given.

Association between influenza vaccination and prognosis in patients with ischemic heart disease: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

There is substantial epidemiological evidence demonstrating that influenza contributes to cardiovascular events in patients who already have cardiovascular diseases. However, the efficacy of influenza vaccination on the prognosis of patients with ischemic heart disease (IHD) is unclear.

METHODS

We conducted a systematic search for eligible randomized controlled trials (RCTs) in PubMed, Cochrane, and Embase on September 13, 2024, to investigate the effects of the influenza vaccine on the prognosis of patients with IHD. The effect sizes were combined using random-effects models, and Trial Sequential Analysis (TSA) was used to assess the reliability and validity of the results.

RESULTS

Five RCTs with a total of 5659 patients (median age ranging from 57.1 to 66 years, 67.8% male) with IHD were included. The use of influenza vaccine reduced the risk of major adverse cardiovascular events (risk ratio [RR] = 0.67, 95% confidence interval [CI] 0.52-0.87, number-needed-to-treat [NNT] of 37, high certainty), cardiovascular death (RR = 0.55, 95% CI 0.35-0.87, moderate certainty), all-cause mortality (RR = 0.58, 95% CI 0.40-0.84, high certainty) and myocardial infarction (MI) (RR = 0.66, 95% CI 0.46-0.93, high certainty) in patients with IHD compared with control. The analysis revealed no significant benefit regarding hospitalization for heart failure (HF) (RR = 0.91, 95% CI 0.21-3.99, moderate certainty) and revascularization (RR = 0.59, 95% CI 0.10-3.45, moderate certainty). The NNT to avoid 1 event was 37 for major adverse cardiovascular events, 56 for cardiovascular death, 67 for MI, and 41 for all-cause death. TSA showed that the benefit of influenza vaccine in reducing MACE was conclusive, no more trials were necessary.

CONCLUSION

This study suggests high level of evidence that the use of influenza vaccine may reduce the risk of major adverse cardiovascular events in patients with IHD.

Structural heart disease in the tropics: A comprehensive review

Structural heart disease (SHD) remains a significant global health challenge, disproportionately impacting populations in tropical regions where the burden of infectious diseases, limited healthcare infrastructure, and socio-economic disparities exacerbate the issue. The tropics are uniquely affected by conditions such as rheumatic heart disease (RHD), endomyocardial fibrosis, tropical cardiomyopathies, and pericardial diseases, often resulting from or complicated by endemic infections like malaria, dengue, tuberculosis, and parasitic diseases. Moreover, Human Immunodeficiency Virus-Associated Cardiac Disease (HIVAC) represents an emerging concern in regions with high HIV prevalence, adding complexity to the interplay between infectious and structural cardiac conditions. Despite the significant morbidity and mortality associated with SHD in these areas, research and clinical focus have often been inadequate, underscoring the need for a comprehensive synthesis of available evidence to guide future efforts. This review aims to provide a detailed examination of SHD in the tropics, with a focus on valvular, myocardial, and pericardial diseases linked to tropical infections and conditions. It highlights the epidemiology, pathophysiology, and clinical presentation of key diseases, including RHD, endocarditis, Chagas disease, and HIVAC, as well as other less commonly recognized tropical cardiomyopathies and pericardial disorders. The review also explores diagnostic challenges, advances in imaging and molecular tools, and the role of public health interventions and policy in addressing these conditions. By synthesizing current knowledge and identifying gaps, this review aims to inform research priorities, improve clinical care, and support the development of tailored prevention and management strategies for SHD in resource-constrained tropical settings.

Influenza vaccine in cardiovascular disease: Current evidence and practice in India

Influenza is a common trigger for cardiovascular events. Temporal association studies of influenza and cardiovascular events have well documented this phenomenon. More recently, randomised clinical trials of influenza vaccine have shown the benefit of immunisation in reducing recurrent cardiovascular events, especially in patients with acute coronary syndrome. Despite this overwhelming benefit, its uptake in India is very low. This could be due to a lack of awareness and paucity of evidence of its benefit in tropical countries like India, where the influenza season is variable and spread throughout the year. In this review, we explore these aspects of influenza and cardiovascular diseases and discuss the way ahead.

Influenza Vaccination and Cardiovascular Events in Japanese Patients With Heart Failure - Findings From the PARALLEL-HF Trial

Background

Influenza is associated with an increased risk for cardiovascular events in patients with heart failure (HF). This study aimed to investigate the prevalence of influenza vaccination among Japanese patients with HF enrolled in the PARALLEL-HF (Prospective comparison of ARNI with ACEi to determine the noveL beneficiaL trEatment vaLue in Japanese Heart Failure patients) trial and the association between receiving influenza vaccination and cardiovascular events including death or HF hospitalization.

Methods and Results

In PARALLEL-HF, in which 223 patients with HF and reduced ejection fraction (HFrEF) were randomized to the angiotensin-receptor neprilysin inhibitor (sacubitril/valsartan) or enalapril, 97 (43%) received influenza vaccination. Influenza vaccination tended to be associated, though statistically not significant, with a lower risk for all-cause death (adjusted hazard ratio [HR]: 0.67; 95% confidence interval [CI]: 0.32-1.39) and cardiopulmonary or influenza-related hospitalization or death (adjusted HR: 0.72; 95% CI: 0.46-1.11) in propensity score-adjusted models.

Conclusions

The influenza vaccination rate in Japanese patients with HFrEF who were well managed on guideline-directed medical therapy was suboptimal despite recommendations from clinical practice guidelines. However, importantly, it could be associated with better clinical benefits.

Association of respiratory infections and the impact of vaccinations on cardiovascular diseases

Influenza, pneumococcal, severe acute respiratory syndrome coronavirus 2, and respiratory syncytial virus infections are important causes of high morbidity and mortality in the elderly. Beyond the burden of infectious diseases, they are also associated with several non-infectious complications like cardiovascular events. A growing body of evidence in prospective studies and meta-analyses has shown the impact of influenza and pneumococcal vaccines on types of cardiovascular outcomes in the general population. Influenza vaccination showed a potential benefit for primary and secondary prevention of cardiovascular diseases across all ages. A reduced risk of cardiovascular events for individuals aged 65 years and older was associated with pneumococcal vaccination. Despite scientific evidence on the effectiveness, safety, and benefits of the vaccines and recommendations to vaccinate elderly patients and those with risk factors, vaccination rates remain sub-optimal in this population. Doubts about vaccine necessity or efficacy and concerns about possible adverse events in patients and physicians refer to delayed acceptance. Vaccination campaigns targeting increasing professional recommendations and public perceptions should be implemented in the coming years. The aim of this review paper is to summarize the effect of vaccination in the field of cardiovascular disease to achieve a higher vaccination rate in this patient population.

Prevalence of Steinert's Myotonic Dystrophy and Utilization of Healthcare Services: A Population-Based Cross-Sectional Study

Myotonic dystrophy type I (MDI) is the most common muscular dystrophy in adults. The main objectives of this study were to determine the prevalence of MDI in the Community of Madrid (CM) (Spain) and to analyze the use of public healthcare services; a population-based cross-sectional descriptive study was carried out on patients with MDI in CM and data were obtained from a population-based registry (2010-2017). A total of 1101 patients were studied (49.1% women) with average age of 47.8 years; the prevalence of MDI was 14.4/100,000 inhabitants. In the women lineal regression model for hospital admissions, being in the fourth quartile of the deprivation index, was a risk factor (regression coef (rc): 0.80; 95%CI 0.25-1.37). In the overall multiple lineal regression model for primary health care (PHC) attendance, being a woman increased the probability of having a higher number of consultations (rc: 3.99; 95%CI: 3.95-5.04), as did being in the fourth quartile of the deprivation index (rc: 2.10; 95%CI: 0.58-3.63); having received influenza vaccines was a protective factor (rc: -0.46; 95%CI: -0.66-(-0.25)). The prevalence of MDI in the CM is high compared to other settings. Moreover, having any level of risk stratification of becoming ill (high, medium or low) has a positive association with increased PHC consultations and hospital admissions.

Influenza Vaccination Coverage among People with Self-Reported Cardiovascular Diseases-Findings from the Hungarian Implementation of the European Health Interview Survey

Worldwide, cardiovascular diseases are the leading cause of mortality. This has significant implications for public health. Influenza, a common infectious disease, poses an increased risk for individuals with chronic conditions, such as cardiovascular diseases. However, little is known about influenza vaccination coverage in this group. This study utilized data from the Hungarian implementation of the European Health Interview Survey to assess influenza vaccination coverage and its determinants among cardiovascular respondents from 2009 to 2019. The findings reveal a downward trend in the vaccination rates over the years (from 24% to 21%), despite the availability of free vaccination in Hungary for this high-risk population. The main factors influencing low influenza vaccine uptake were identified, as follows: young age, a lower level of education, good self-perceived health status, smoking, a lower frequency of medical visits, and not suffering from respiratory diseases. Addressing these disparities necessitates targeted vaccination strategies supported by enhanced education, better access to healthcare services, and the promotion of preventive healthcare measures. Improving vaccination coverage among patients with cardiovascular diseases is imperative for reducing influenza-related morbidity and mortality. This highlights the importance of comprehensive public health interventions and healthcare provider engagement in promoting vaccination among groups at increased risk.

Exposome in ischaemic heart disease: beyond traditional risk factors

Ischaemic heart disease represents the leading cause of morbidity and mortality, typically induced by the detrimental effects of risk factors on the cardiovascular system. Although preventive interventions tackling conventional risk factors have helped to reduce the incidence of ischaemic heart disease, it remains a major cause of death worldwide. Thus, attention is now shifting to non-traditional risk factors in the built, natural, and social environments that collectively contribute substantially to the disease burden and perpetuate residual risk. Of importance, these complex factors interact non-linearly and in unpredictable ways to often enhance the detrimental effects attributable to a single or collection of these factors. For this reason, a new paradigm called the 'exposome' has recently been introduced by epidemiologists in order to define the totality of exposure to these new risk factors. The purpose of this review is to outline how these emerging risk factors may interact and contribute to the occurrence of ischaemic heart disease, with a particular attention on the impact of long-term exposure to different environmental pollutants, socioeconomic and psychological factors, along with infectious diseases such as influenza and COVID-19. Moreover, potential mitigation strategies for both individuals and communities will be discussed.

Influenza vaccination and use of lipid lowering therapies in adults with atherosclerotic cardiovascular disease: An analysis of the Behavioral Risk Factor Surveillance System (BRFSS)

BACKGROUND

Influenza vaccination and lipid lowering therapy (LLT) are evidence-based interventions with substantial benefit for individuals with established atherosclerotic cardiovascular disease (ASCVD). However, levels of influenza immunization and LLT use are low, possibly due to pervasive fear-based misinformation uniquely targeting vaccines and LLT. Whether being unvaccinated for influenza predicts lower utilization of LLT is unknown.

OBJECTIVES

We tested the hypothesis that American adults with ASCVD who are unvaccinated for influenza have lower use of LLT even after accounting for traditional factors associated with underuse of preventive therapies.

METHODS

We pooled 2017, 2019, and 2021 survey data from the Behavioral Risk Factor Surveillance System (BRFSS), and selected respondents aged 40 to 75 years with self-reported ASCVD. We used logistic regression models adjusted for potential confounders to examine the association between influenza vaccination and self-reported LLT use. We performed a sensitivity analysis with multiple imputation to account for missing data. All analyses accounted for complex survey weighting.

RESULTS

Of 66,923 participants with ASCVD, 55% reported influenza vaccination in the last year and 76% reported using LLT. Being unvaccinated for influenza was associated with lower odds of LLT use (OR 0.54; 95% CI 0.50, 0.58; P< .001). In a multivariable regression model adjusting for demographics and comorbidities, this association remained statistically significant (aOR 0.58, 95% CI 0.52, 0.64, P < .001). After additional adjustment for preventive care engagement, health care access, and use patterns of other cardiovascular medications this association persisted (aOR 0.66; 95% CI 0.60, 0.74; P < .001). There were no significant differences across subgroups, including those with and without hyperlipidemia.

CONCLUSIONS

Unvaccinated status for influenza was independently associated with 34% lower odds of LLT use among American adults with ASCVD after adjustment for traditional factors linked to underuse of preventive therapies. This finding identifies a population with excess modifiable ASCVD risk, and supports investigation into nontraditional mechanisms driving underuse of preventive therapies, including fear-based misinformation.

World Heart Federation Roadmap for Secondary Prevention of Cardiovascular Disease: 2023 Update

Background

Secondary prevention lifestyle and pharmacological treatment of atherosclerotic cardiovascular disease (ASCVD) reduce a high proportion of recurrent events and mortality. However, significant gaps exist between guideline recommendations and usual clinical practice.

Objectives

Describe the state of the art, the roadblocks, and successful strategies to overcome them in ASCVD secondary prevention management.

Methods

A writing group reviewed guidelines and research papers and received inputs from an international committee composed of cardiovascular prevention and health systems experts about the article's structure, content, and draft. Finally, an external expert group reviewed the paper.

Results

Smoking cessation, physical activity, diet and weight management, antiplatelets, statins, beta-blockers, renin-angiotensin-aldosterone system inhibitors, and cardiac rehabilitation reduce events and mortality. Potential roadblocks may occur at the individual, healthcare provider, and health system levels and include lack of access to healthcare and medicines, clinical inertia, lack of primary care infrastructure or built environments that support preventive cardiovascular health behaviours. Possible solutions include improving health literacy, self-management strategies, national policies to improve lifestyle and access to secondary prevention medication (including fix-dose combination therapy), implementing rehabilitation programs, and incorporating digital health interventions. Digital tools are being examined in a range of settings from enhancing self-management, risk factor control, and cardiac rehab.

Conclusions

Effective strategies for secondary prevention management exist, but there are barriers to their implementation. WHF roadmaps can facilitate the development of a strategic plan to identify and implement local and national level approaches for improving secondary prevention.

Influenza vaccination and major cardiovascular risk: a systematic review and meta-analysis of clinical trials studies

Cardiovascular events remain a substantial global health concern, necessitating innovative strategies for prevention. This study aims to assess the potential impact of influenza vaccination on major cardiovascular events. A search of the medical English literature was conducted using PubMed/MEDLINE, EMBASE, and the Cochrane CENTRAL up to 1 August 2023. Meta-analysis and stratified analyses were performed to investigate specific outcomes, including myocardial infarction (MI), cardiovascular death, and stroke. Pooled relative risks (RR) along with their 95% confidence intervals (CI) were calculated to evaluate the associations. A comprehensive analysis was conducted on a total of 9059 patients, with 4529 patients receiving the influenza vaccine and 4530 patients receiving a placebo. Among patients who received the influenza vaccine, a notable reduction in the occurrence of major cardiovascular events was observed, with 517 cases compared to 621 cases in the placebo group (RR 0.70; 95% CI 0.55-0.91). The stratified analysis revealed a decreased risk of MI in vaccinated patients (RR 0.74; 95% CI 0.56-0.97) and a significant reduction in cardiovascular death events (RR 0.67; 95% CI 0.45-0.98). This study provides compelling evidence that influenza vaccination is associated with a decreased risk of major cardiovascular events, particularly myocardial infarction, and cardiovascular death. These findings highlight the potential of influenza vaccination as an adjunctive strategy in cardiovascular disease prevention. Further research and exploration of underlying mechanisms are warranted to elucidate the observed beneficial effects.

P. G, Goyal D, Malhotra RK, Mishra P, Shukla M, Gupta A, Kohli V, Bundela N, Batra V, Bansal A, Yadav R, Yusuf J, Mukhopadhyay S. Impact of COVID-19 vaccination on mortality after acute myocardial infarction

BACKGROUND

COVID-19 vaccines are highly immunogenic but cardiovascular effects of these vaccines have not been properly elucidated.

OBJECTIVES

To determine impact of COVID-19 vaccination on mortality following acute myocardial infarction (AMI).

METHODS

This was a single center retrospective observation study among patients with AMI enrolled in the the North India ST-Elevation Myocardial Infarction (NORIN-STEMI) registry. In all the enrolled patients, data regarding patient's vaccination status including details on type of vaccine, date of vaccination and adverse effects were obtained. All enrolled subjects were followed up for a period of six months. The primary outcome of the study was all-cause mortality both at one month and at six months of follow-up. Propensity-weighted score logistic regression model using inverse probability of treatment weighting was used to determine the impact of vaccination status on all-cause mortality.

RESULTS

A total of 1578 subjects were enrolled in the study of whom 1086(68.8%) were vaccinated against COVID-19 while 492(31.2%) were unvaccinated. Analysis of the temporal trends of occurrence of AMI post vaccination did not show a specific clustering of AMI at any particular time. On 30-day follow-up, all-cause mortality occurred in 201(12.7%) patients with adjusted odds of mortality being significantly lower in vaccinated group (adjusted odds ratio[aOR]: 0.58, 95% CI: 0.47-0.71). Similarly, at six months of follow-up, vaccinated AMI group had lower odds of mortality(aOR: 0.54, 95% CI: 0.44 to 0.65) as compared to non-vaccinated group.

CONCLUSIONS

COVID-19 vaccines have shown to decrease all-cause mortality at 30 days and six months following AMI.

Readmissions for Myocardial Infarction Among Survivors of COVID-19 Hospitalization: Nationwide Analysis From Pandemic Year 2020

Background

COVID-19 is known to be associated with acute myocardial infarction (MI).

Objectives

The purpose of this study was to evaluate the outcomes of 30-day readmissions for MI among survivors of COVID-19 hospitalization.

Methods and Results

We used the U.S. Nationwide Readmission Database to identify COVID-19 admissions from April 1, 2020, to November 30, 2020, using International Classification of Diseases-10th Revision-Clinical Modification (ICD-10-CM) claims. The primary outcome was 30-day readmission incidence for MI. A total of 521,251 cases of COVID-19 were included, of which 11.6% were readmitted within 30 days of discharge. The 30-day readmission incidence for MI was 0.6%. The 30-day all-cause readmission mortality incidence was 1.3%. Patients readmitted for MI were more frequently males (61.6% vs 38.4%) and had a higher Charlson comorbidity burden score (7 vs 4). The most common diagnosis among 30-day MI readmission was type 2 MI (51.1%), followed by a diagnosis of a type 1 non-ST-segment elevation MI (41.7%). ST-segment elevation MI cases constituted 7.6% of all MI-readmission whereas 0.6% of patients had unstable angina. 30-day MI readmissions with a recurrent diagnosis of COVID-19 had higher readmission mortality and incidence of complications. Conversely, the odds of performing revascularization procedures were lower for MI with recurrent COVID-19. Furthermore, MI readmissions with recurrent COVID-19 had a higher length of stay (7 vs 5 days) and cost of hospitalization ($18,398 vs $16,191) when compared with non-COVID-19 MI readmissions.

Conclusions

Among survivors of COVID-19 hospitalization, 5.2% of all-cause 30-day readmissions and 12% of all-cause readmission mortality were attributed to MI. MI-related readmissions were a significant source of mortality, morbidity, and resource utilization.

Thirty-Day Cardiovascular Readmissions Following Discharge with COVID-19: A US Nationwide Readmission Database Analysis from the Pandemic Year 2020

BACKGROUND

COVID-19 is known to be associated with a myriad of cardiovascular (CV) complications during acute illness, but the rates of readmissions for CV complications after COVID-19 infection are less well established.

METHODS

The U.S Nationwide Readmission Database was utilized to identify COVID-19 admissions from April 1st to November 30th, 2020 using ICD-10-CM administrative claims.

RESULTS

A total of 521,351 admissions for COVID-19 were identified. The all-cause 30-day readmission rate was 11.6% (n=60,262). The incidence of CV readmissions was 5.1% (n=26,725), accounting for 44.3% of all-cause 30-day readmissions. Both CV and non-CV readmissions occurred at a median of 7 days. Patients readmitted with CV causes had a higher comorbidity burden with Charlson comorbidity median score of 6. The most common CV cause of readmission was acute heart failure (HF) (8.5%) followed by acute myocardial infarction (MI) (5.2%). Venous thromboembolism and stroke during 30-day readmission occurred at a rate of 4.6% and 3.6%, respectively. Stress cardiomyopathy and acute myocarditis were less frequent with an incidence of 0.1% and 0.2%, respectively. CV readmissions were associated with higher mortality compared with non-CV readmissions (16.5% vs. 7.5%, p<0.01). Each 30-day CV readmission was associated with greater cost of care than each non-CV readmission ($13,803 vs. $10,310, p=<0.01).

CONCLUSIONS

Among survivors of index COVID-19 admission, 44.7% of all 30-day readmissions were attributed to CV causes. Acute HF remains the most common cause of readmission after COVID-19, followed closely by acute MI. CV causes of readmissions remain a significant source of mortality, morbidity, and resource utilization.

Vaccines and cardiovascular outcomes: lessons learned from influenza epidemics

Cardiovascular disease (CVD) is the leading cause of death in the world and is largely preventable. An increasing amount of evidence suggests that annual influenza vaccination reduces CVD-related morbidity and mortality. Despite various clinical guidelines recommending annual influenza vaccination for the general population for influenza-like illness risk reduction, with a particular emphasis on people with CVD, vaccination rates fall consistently below the goal established by the World Health Organization. This review outlines the importance of influenza vaccination, mechanisms of cardiovascular events in influenza, summarizing the available literature on the effects of influenza vaccine in CVD and the benefits of influenza vaccine during the COVID-19 pandemic.

Predictors of Seasonal Influenza Vaccination Willingness among High-Risk Populations Three Years after the Onset of the COVID-19 Pandemic

High-risk populations are at increased risk of severe influenza-related illness, hospitalization, and death due to influenza. The aim of our study was to assess the willingness of high-risk populations to take the influenza vaccine for the 2022-2023 season, and to investigate the factors associated with such willingness. We conducted a cross-sectional study in Greece in September 2022 using a convenience sample. We considered demographic characteristics, COVID-19-related variables, resilience, social support, anxiety, depression, and COVID-19-related burnout as potential predictors. Among participants, 39.4% were willing to accept the seasonal influenza vaccine, 33.9% were unwilling, and 26.8% were hesitant. Multivariable analysis identified that increased age and increased family support were associated with increased influenza vaccination willingness. Moreover, participants that have received COVID-19 booster doses were more willing to accept the influenza vaccine. In contrast, adverse effects because of COVID-19 vaccination and exhaustion due to measures against COVID-19 reduced influenza vaccination willingness. We found that the intention of high-risk populations to receive the influenza vaccine was low. Our study contributes to an increased understanding of the factors that affect vaccination willingness. Public health authorities could use this information to update vaccination programs against influenza. Emphasis should be given on safety and effectiveness issues.