Influenza vaccination and secondary prevention of cardiovascular disease among Taiwanese elders-A propensity score-matched follow-up study

2025 Expert Consensus Recommendations on Vaccinations in Adults with High Cardiovascular Risk and Cardiovascular Disease: A Report of the Task Force of the Taiwan Society of Cardiology and the Infectious Diseases Society of Taiwan

Cardiovascular disease (CVD) is a leading cause of death worldwide, and infections often worsen the clinical condition of these patients. Respiratory infections, either bacterial or viral sources, are important causes of high morbidity and mortality in older adults. Beyond the burden of infection-related complications, they are also associated with non-infection-related complications such as cardiovascular (CV) events. For example, herpes zoster is associated with an increased risk of stroke and myocardial infarction. Vaccination is an effective preventive strategy for patients with CVD by reducing viral and bacterial infections, and minimizing systemic inflammatory responses to support plaque stability and reduce the likelihood of CV events in high-risk patients, thereby reducing the risks of CV and non-CV hospitalizations and mortality. Despite evidence on the effectiveness, safety, and benefits of vaccines and recommendations to vaccinate older patients and those with risk factors, vaccination rates remain sub-optimal in this population. The Taiwan Society of Cardiology and the Infectious Diseases Society of Taiwan recently appointed a task force to formulate a consensus on vaccinations for adults with high CV risk or CVD. Based on the most up-to-date information, the consensus provides current evidence-based important recommendations.

[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 reduce the risk of major adverse cardiovascular events in patients with IHD.

Role of Influenza Vaccination in Cardiovascular Disease: Systematic Review and Meta-Analysis

Influenza vaccination has shown great promise in terms of its cardioprotective effects. The aim of our analysis is to provide evidence regarding the protective effects of influenza vaccination in patients with cardiovascular disease. We conducted a systematic literature search to identify trials assessing the cardiovascular outcomes of influenza vaccination. Summary effects were calculated using a DerSimonian and Laird fixed effects and random effects model as odds ratio with 95% confidence intervals (CIs) for all the clinical endpoints. Fifteen studies with a total of 745,001 patients were included in our analysis. There was lower rates of all-cause mortality [odds ratio (OR) = 0.74, 95% CI 0.64-0.86], cardiovascular death (OR = 0.73, 95% CI 0.59-0.92), and stroke (OR = 0.71, 95% CI 0.57-0.89) in patients who received the influenza vaccine compared to placebo. There was no significant statistical difference in rates of myocardial infarction (OR = 0.91, 95% CI 0.69-1.21) or heart failure hospitalizations (OR = 1.06, 95% CI 0.85-1.31) in the 2 cohorts. In patients with cardiovascular disease, influenza vaccination is associated with lower all-cause mortality, cardiovascular death, and stroke.

Determinants of uptake of influenza, zoster and pneumococcal vaccines in patients with cardiovascular diseases

BACKGROUND

Globally, cardiovascular disease (CVD) is the leading cause of death and illness. Vaccine-preventable infections may increase acute coronary vascular disease events and the risk of complications. Low vaccine coverage has been reported among adults at high risk of complications from vaccine-preventable infections. There is a gap in research evidence around determinants of uptake of vaccines among adults with CVD. This study examined the uptake of influenza, pneumococcal and zoster vaccines and the determinants of uptake of the vaccines among cardiac patients.

METHOD

A prospective cross-sectional study was carried out among hospitalised cardiac patients through an interviewer-administered questionnaire. Descriptive statistics were used to investigate self-reported uptake of influenza, pneumococcal and zoster vaccines. Univariate and multivariate analyses of participants' social demographic and clinical characteristics were conducted to identify factors for receiving influenza vaccine.

RESULTS

Low vaccination rates among 104 participants were found for influenza (45.2%), pneumococcal (13.5%) and zoster (5.8%) vaccines. The most common reason for not receiving influenza vaccine was concern about side effects. Lack of awareness about the pneumococcal and zoster vaccines was the main reason for the poor uptake of these vaccines. Australia-born participants were more likely to receive influenza vaccine than overseas-born participants. Working-age participants and, interestingly, people living with a current smoker were less likely to receive influenza vaccine.

CONCLUSION

Influenza, pneumococcal and zoster vaccine uptake among cardiac patients was low. Encouraging physician recommendations for vaccination for cardiac patients under 65 years of age and addressing vaccination challenges among people from culturally and linguistically diverse backgrounds and pharmacy, workplace, and hospital vaccination may help increase vaccination uptake among cardiac patients.

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.

Effectiveness of Vaccines and Monoclonal Antibodies Against Respiratory Syncytial Virus: Generic Protocol for Register-Based Cohort Study

Several immunization products are currently being developed against respiratory syncytial virus (RSV) for children, pregnant females, and older adults, and some products have already received authorization. Therefore, studies to monitor the effectiveness of these products are needed in the following years. To assist researchers to conduct postmarketing studies, we developed a generic protocol for register-based cohort studies to evaluate immunization product effectiveness against RSV-specific and nonspecific outcomes. To conduct a study on the basis of this generic protocol, the researchers can use any relevant databases or healthcare registers that are available at the study site.

Impact of influenza, herpes zoster, and pneumococcal vaccinations on the incidence of cardiovascular events in subjects aged over 65 years: a systematic review

This systematic review aims to summarize the impact of vaccination against influenza, shingles, and pneumococcus on the incidence on the risk of cardiovascular events in the elderly. This protocol was developed in accordance with PRISMA guidelines. We conducted a literature search and identified all relevant articles published regarding the matter up to September 2022. We retrieved 38 studies (influenza vaccine = 33, pneumococcal vaccine = 5, and zoster vaccine = 2). A total of 28 and 2 studies have shown that influenza and pneumococcal vaccines significantly lower the risk of cardiovascular disease in the elderly. Also, repeated influenza vaccination shows a consistent and dose-dependent protective effect against acute coronary syndromes and stroke. Moreover, dual influenza and pneumococcal vaccination was associated with lower risks of some cardiovascular events (stroke, congestive heart failure, ischemic heart disease, and myocardial infarction). However, the impact of PCV13 on cardiovascular events has not been studied, nor has the currently recommended vaccination schedule (PCV13 + PPV23). As for herpes zoster vaccination, only the protective effect against stroke has been studied with the live attenuated herpes zoster vaccine, but no studies have been conducted with the recombinant subunit herpes zoster vaccine. This review outlines the benefits of the vaccines mentioned above beyond their preventive action on infectious diseases. It is intended for health professionals who wish to inform and advise their elderly patients.

Risk of Worsening Heart Failure and All-Cause Mortality Following COVID-19 Vaccination in Patients With Heart Failure: A Nationwide Real-World Safety Study

BACKGROUND

Patients with heart failure are vulnerable to the SARS-CoV-2 infection. However, limited evidence exists on the safety of the SARS-CoV-2 mRNA vaccines in this patient population. The objective of this study was to investigate the risk of all-cause mortality, worsening heart failure, venous thromboembolism, and myocarditis associated with the mRNA vaccines in patients with heart failure.

METHODS

Using Danish nationwide registries, 2 cohorts were constructed: (1) all prevalent heart failure patients in 2019 aged 40 to 95 years and (2) all prevalent heart failure patients in 2021 aged 40 to 95 years, who were vaccinated with either of the 2 mRNA vaccines (BNT162B2 or mRNA-1273). The patients in the 2 cohorts were matched 1:1 using exact exposure matching on age, sex, and duration of heart failure. To estimate standardized absolute risks, outcome-specific Cox regression analyses were performed.

RESULTS

The total study population comprised 101 786 patients. The median age of the study population was 74 years (interquartile range, 66-81). The standardized risk of all-cause mortality within 90 days was 2.23% (95% CI, 2.10%-2.36%) in the vaccinated cohort and 2.56% (95% CI, 2.43%-2.70%) in the unvaccinated cohort (90-day risk difference, -0.33% [95% CI, -0.52% to -0.15%]). The standardized risk of worsening heart failure within 90 days was 1.10% (95% CI, -1.01% to 1.19%) in the 2021 (vaccinated) cohort and 1.08% (95% CI, 0.99%-1.17%) in the 2019 (unvaccinated) cohort (risk difference, 0.02% [95% CI, -0.11% to 0.15%]). No significant differences were found regarding venous thromboembolism or myocarditis.

CONCLUSIONS

Receiving an mRNA vaccine was not associated with an increased risk of worsening heart failure, myocarditis, venous thromboembolism, or all-cause mortality.

2023 Guidelines of the Taiwan Society of Cardiology on the Diagnosis and Management of Chronic Coronary Syndrome

Coronary artery disease (CAD) covers a wide spectrum from persons who are asymptomatic to those presenting with acute coronary syndromes (ACS) and sudden cardiac death. Coronary atherosclerotic disease is a chronic, progressive process that leads to atherosclerotic plaque development and progression within the epicardial coronary arteries. Being a dynamic process, CAD generally presents with a prolonged stable phase, which may then suddenly become unstable and lead to an acute coronary event. Thus, the concept of "stable CAD" may be misleading, as the risk for acute events continues to exist, despite the use of pharmacological therapies and revascularization. Many advances in coronary care have been made, and guidelines from other international societies have been updated. The 2023 guidelines of the Taiwan Society of Cardiology for CAD introduce a new concept that categorizes the disease entity according to its clinical presentation into acute or chronic coronary syndromes (ACS and CCS, respectively). Previously defined as stable CAD, CCS include a heterogeneous population with or without chest pain, with or without prior ACS, and with or without previous coronary revascularization procedures. As cardiologists, we now face the complexity of CAD, which involves not only the epicardial but also the microcirculatory domains of the coronary circulation and the myocardium. New findings about the development and progression of coronary atherosclerosis have changed the clinical landscape. After a nearly 50-year ischemia-centric paradigm of coronary stenosis, growing evidence indicates that coronary atherosclerosis and its features are both diagnostic and therapeutic targets beyond obstructive CAD. Taken together, these factors have shifted the clinicians' focus from the functional evaluation of coronary ischemia to the anatomic burden of disease. Research over the past decades has strengthened the case for prevention and optimal medical therapy as central interventions in patients with CCS. Even though functional capacity has clear prognostic implications, it does not include the evaluation of non-obstructive lesions, plaque burden or additional risk-modifying factors beyond epicardial coronary stenosis-driven ischemia. The recommended first-line diagnostic tests for CCS now include coronary computed tomographic angiography, an increasingly used anatomic imaging modality capable of detecting not only obstructive but also non-obstructive coronary plaques that may be missed with stress testing. This non-invasive anatomical modality improves risk assessment and potentially allows for the appropriate allocation of preventive therapies. Initial invasive strategies cannot improve mortality or the risk of myocardial infarction. Emphasis should be placed on optimizing the control of risk factors through preventive measures, and invasive strategies should be reserved for highly selected patients with refractory symptoms, high ischemic burden, high-risk anatomies, and hemodynamically significant lesions. These guidelines provide current evidence-based diagnosis and treatment recommendations. However, the guidelines are not mandatory, and members of the Task Force fully realize that the treatment of CCS should be individualized to address each patient's circumstances. Ultimately, the decision of healthcare professionals is most important in clinical practice.

Influenza vaccination reduced myocardial infarctions in United Kingdom older adults: a prior event rate ratio study

OBJECTIVES

We aimed to estimate the real-world effectiveness of the influenza vaccine against myocardial infarction (MI) and influenza in the decade since adults aged ≥ 65 years were first recommended the vaccine.

STUDY DESIGN AND SETTING

We identified annual cohorts, 1997 to 2011, of adults aged ≥ 65 years, without previous influenza vaccination, from UK general practices, registered with the Clinical Practice Research Datalink. Using a quasi-experimental study design to control for confounding bias, we estimated influenza vaccine effectiveness on hospitalization for MI, influenza, and antibiotic prescriptions for lower respiratory tract infections.

RESULTS

Vaccination was moderately effective against influenza, the prior event rate ratio-adjusted hazard ratios ranging from 0.70 in 1999 to 0.99 in 2001. Prior event rate ratio-adjusted hazard ratios demonstrated a protective effect against MIs, varying between 0.40 in 2010 and 0.89 in 2001. Aggregated across the cohorts, influenza vaccination reduced the risk of MIs by 39% (95% confidence interval: 34%, 44%).

CONCLUSION

Effectiveness of the flu vaccine in preventing MIs in older UK adults is consistent with the limited evidence from clinical trials. Similar trends in effectiveness against influenza and against MIs suggest the risk of influenza mediates the effectiveness against MIs, although divergence in some years implies the mechanism may be complex.

Cardioprotective effects of Influenza Vaccination among Patients with Established Cardiovascular Disease or at High Cardiovascular Risk: A Systematic Review and Meta-analysis

BACKGROUND

The clinical impact of the influenza vaccination on cardiovascular outcomes in people with established cardiovascular disease (CVD) is still debated.

AIM

The aim of this meta-analysis was to estimate the effect of influenza vaccination on cardiovascular and cerebrovascular outcomes among patients with established CVD.

METHODS

We systematically searched all electronic databases from inception until 15 April 2022. Primary clinical outcomes were all-cause mortality (ACM), and major adverse clinical events (MACE). Secondary endpoints were heart failure, myocardial infarction, CV mortality, and stroke.

RESULTS

Eighteen articles (five randomized trials and thirteen observational studies), with a total of 22,532,165 patients were included in the analysis. There were 217,072 participants included in the high cardiovascular risk or established CVD population (vaccinated n = 111,073 and unvaccinated n = 105,999). The mean age of the patients was 68 years old, without any difference between groups (69 vs 71) years. At mean follow-up of 1.5 years, vaccinated group was associated with lower risk for all-cause mortality [HR, 0.71(95%CI, 0.63-0.80), p < 0.001], MACE [HR, 0.83(95%CI:0.72-0.96), p = 0.01], CV mortality [HR, 0.78(95%CI:0.68-0.90), p < 0.001] and myocardial infarction [HR, 0.82(95%CI:0.74-0.92), p < 0.001] compared to unvaccinated group. While incidence of stroke [HR, 1.03 (95%CI, 0.92-1.06), p = 0.61] and heart failure [HR, 0.74 (95%CI, 0.51-1.08), p = 0.12] did not differ between the two groups.

CONCLUSION

Influenza vaccination reduced major adverse clinical events, all-cause mortality, CV mortality and myocardial infarction. These highlighted the importance of influenza vaccination in established CVD or high cardiovascular risk.

Preventing heart failure: a position paper of the Heart Failure Association in collaboration with the European Association of Preventive Cardiology

The heart failure epidemic is growing and its prevention, in order to reduce associated hospital readmission rates and its clinical and economic burden, is a key issue in modern cardiovascular medicine. The present consensus document aims to provide practical evidence-based information to support the implementation of effective preventive measures. After reviewing the most common risk factors, an overview of the population attributable risks in different continents is presented, to identify potentially effective opportunities for prevention and to inform preventive strategies. Finally, potential interventions that have been proposed and have been shown to be effective in preventing HF are listed.

Preventing heart failure: a position paper of the Heart Failure Association in collaboration with the European Association of Preventive Cardiology

The heart failure epidemic is growing and its prevention, in order to reduce associated hospital readmission rates and its clinical and economic burden, is a key issue in modern cardiovascular medicine. The present position paper aims to provide practical evidence-based information to support the implementation of effective preventive measures. After reviewing the most common risk factors, an overview of the population attributable risks in different continents is presented, to identify potentially effective opportunities for prevention and to inform preventive strategies. Finally, potential interventions that have been proposed and have been shown to be effective in preventing heart failure are listed.

Influenza vaccination and prognosis for patients with high cardiovascular risk

Cardiovascular and respiratory diseases have been one of the leading causes of mortality in the world for over 15 years. According to the results of various studies, a clear connection was revealed between the incidence of influenza and the decompensation of cardiovascular diseases, which leads to the development of acute coronary syndrome, acute heart failure and myocardial infarction. Also, the incidence of influenza is associated with an increase in the length of hospitalization, treatment costs and patient mortality. Influenza vaccination, especially in patients with high cardiovascular risk, is one of the most important secondary prevention measures. The article is dedicated to an overview of the problems of vaccination against influenza, the study of the prognosis of patients with high cardiovascular risk, as well as general points in the pathogenesis of influenza and cardiovascular diseases.

The Role of Noncommunicable Diseases in the Pursuit of Global Health Security

Noncommunicable diseases and their risk factors are important for all aspects of outbreak preparedness and response, affecting a range of factors including host susceptibility, pathogen virulence, and health system capacity. This conceptual analysis has 2 objectives. First, we use the Haddon matrix paradigm to formulate a framework for assessing the relevance of noncommunicable diseases to health security efforts throughout all phases of the disaster life cycle: before, during, and after an event. Second, we build upon this framework to identify 6 technical action areas in global health security programs that are opportune integration points for global health security and noncommunicable disease objectives: surveillance, workforce development, laboratory systems, immunization, risk communication, and sustainable financing. We discuss approaches to integration with the goal of maximizing the reach of global health security where infectious disease threats and chronic disease burdens overlap.

Effects of Influenza Vaccine on Mortality and Cardiovascular Outcomes in Patients With Cardiovascular Disease: A Systematic Review and Meta-Analysis

Background

Influenza infection causes considerable morbidity and mortality in patients with cardiovascular disease. We assessed the effects of the influenza vaccine on mortality and cardiovascular outcomes in patients with cardiovascular disease.

Methods and Results

We searched PubMed, Embase, and the Cochrane Library through January 2020 for randomized controlled trials and observational studies assessing the effects of influenza vaccine on mortality and cardiovascular outcomes in patients with cardiovascular disease. Estimates were reported as random effects risk ratios (RRs) with 95% CIs. Analyses were stratified by study design into randomized controlled trials and observational studies. A total of 16 studies (n=237 058), including 4 randomized controlled trials (n=1667) and 12 observational studies (n=235 391), were identified. Participants' mean age was 69.2±7.01 years, 36.6% were women, 65.1% had hypertension, 31.1% had diabetes mellitus, and 23.4% were smokers. At a median follow‐up duration of 19.5 months, influenza vaccine was associated with a lower risk of all‐cause mortality (RR, 0.75; 95% CI, 0.60–0.93 [P=0.01]), cardiovascular mortality (RR, 0.82; 95% CI, 0.80–0.84 [P<0.001]), and major adverse cardiovascular events (RR, 0.87; 95% CI, 0.80–0.94 [P<0.001]) compared with control. The use of the influenza vaccine was not associated with a statistically significant reduction of myocardial infarction (RR, 0.73; 95% CI, 0.49–1.09 [P=0.12]) compared with control.

Conclusions

Data from both randomized controlled trials and observational studies support the use of the influenza vaccine in adults with cardiovascular disease to reduce mortality and cardiovascular events, as currently supported by clinical guidelines. Clinicians and health systems should continue to promote the influenza vaccine as part of comprehensive secondary prevention.

COVID-19 and cardiac injury: clinical manifestations, biomarkers, mechanisms, diagnosis, treatment, and follow up

INTRODUCTION

Coronavirus disease 2019 (COVID-19) has the characteristics of high transmission, diverse clinical manifestations, and a long incubation period. In addition to infecting the respiratory system, COVID-19 also has adverse effects on the cardiovascular system. COVID-19 causes acute myocardial injuries, as well as chronic damage to the cardiovascular system.

AREAS COVERED

The present review is aimed at providing current information on COVID-19 and the cardiovascular system. PubMed, Scopus, Science direct, and Google Scholar were searched.

EXPERT OPINION

It is suggested that heart injury caused by COVID-19 infection might be an important cause of severe clinical phenotypes or adverse events in affected patients. Myocardial damage is closely related to the severity of the disease and even the prognosis in patients with COVID-19. In addition to disorders that are caused by COVID-19 on the cardiovascular system, more protection should be employed for patients with preexisting cardiovascular disease (CVD). Hence, it is very important that once relevant symptoms appear, patients with COVID-19 be rapidly treated to reduce mortality. Thus, early measurements of cardiac damage via biomarkers following hospitalization for COVID-19 infections in a patient with preexisting CVD are recommended, together with careful monitoring of any myocardial injury that might be caused by the infection.Abbreviations: ICU: An intensive care unit; 2019-nCoV: 2019 novel coronavirus; ACEI: ACE inhibitor; ACS: Acute coronary syndrome; ARDS: Acute respiratory distress syndrome; AT1R: Ang II type 1 receptor; ATP: Adenosine triphosphate; ACC: American College of Cardiology; ACE: Angiotensin converting enzyme; Ang II: Angiotensin II; ARB: Angiotensin II receptor blocker; AV block: Atrioventricular block; CAD: Coronary artery disease; CVD: Cardiovascular disease; CT: Computerized tomography; CHF: Congestive heart failure; CHD: Coronary heart disease; CK-MB: Creatine kinase isoenzyme-MB; CRP: C-reactive protein; cTnI: Cardiac troponin I; EAT: Epicardial adipose tissue; ECMO: Extracorporeal membrane oxygenation; FDA: Food and Drug Administration; G-CSF: Granulocyte colony-stimulating factor; HFrEF: HF with a reduced ejection fraction; synhACE2: Human isoform of ACE2; IL: Interleukin; IABP: Intra-aortic balloon counterpulsation; IP10: Interferon γ-induced protein 10 kDa; LPC: Lysophosphatidylcholine; Mas: Mitochondrial assembly receptor; MCP1: Monocyte chemoattractant protein-1; MERS: Middle East respiratory syndrome; MIP1a: macrophage inflammatory protein 1a: MOF: Multiple organ failure; MI: Myocardial infarction; MRI: Magnetic resonance imaging; MYO: Myohe-moglobin; NT-proBNP: N-terminal pro-brain natriuretic peptide; PCPS: Percutaneous cardiopulmonary assistance; rhACE2: Recombinant human ACE2; SARS: Severe acute respiratory syndrome; Th: T helper; RAS: Renin-angiotensin system; TNF-α: Tumor necrosis factor-α; WHO: World Health Organization.

Cardiovascular implications of COVID-19 versus influenza infection: a review

BACKGROUND

Due to the overlapping clinical features of coronavirus disease 2019 (COVID-19) and influenza, parallels are often drawn between the two diseases. Patients with pre-existing cardiovascular diseases (CVD) are at a higher risk for severe manifestations of both illnesses. Considering the high transmission rate of COVID-19 and with the seasonal influenza approaching in late 2020, the dual epidemics of COVID-19 and influenza pose serious cardiovascular implications. This review highlights the similarities and differences between influenza and COVID-19 and the potential risks associated with coincident pandemics.

MAIN BODY

COVID-19 has a higher mortality compared to influenza with case fatality rate almost 15 times more than that of influenza. Additionally, a significantly increased risk of adverse outcomes has been noted in patients with CVD, with ~ 15 to 70% of COVID-19 related deaths having an underlying CVD. The critical care need have ranged from 5 to 79% of patients hospitalized due to COVID-19, a proportion substantially higher than with influenza. Similarly, the frequency of vascular thrombosis including deep venous thrombosis and pulmonary embolism is markedly higher in COVID-19 patients compared with influenza in which vascular complications are rarely seen. Unexpectedly, while peak influenza season is associated with increased cardiovascular hospitalizations, a decrease of ~ 50% in cardiovascular hospitalizations has been observed since the first diagnosed case of COVID-19, owing in part to deferred care.

CONCLUSION

In the coming months, increasing efforts towards evaluating new interventions will be vital to curb COVID-19, especially as peak influenza season approaches. Currently, not enough data exist regarding co-infection of COVID-19 with influenza or how it would progress clinically, though it may cause a significant burden on an already struggling health care system. Until an effective COVID-19 vaccination is available, high coverage of influenza vaccination should be of utmost priority.

Protective effect of influenza vaccination on cardiovascular diseases: a systematic review and meta-analysis

Cardiovascular diseases (CVDs) are among the leading causes of mortality and morbidity worldwide. There are many contrasting ideas on the effectiveness of influenza vaccination on CVDs. This study aimed to investigate the association between influenza vaccination and the risk of CVDs. We systematically searched all PubMed/Medline, EMBASE, and the Cochrane library entries up to November 2019 for studies of influenza vs. the CVDs outcomes. We conducted a random-effects meta‐analysis using the inverse variance method for pooled risk ratios (RR) or odds ratios (OR) and evaluated statistical heterogeneity using the I² statistic. We identified 17 studies (6 randomized controlled trial [RCT], 5 cohorts, and 6 case–control) with a total of 180,043 cases and 276,898 control participants. The pooled RR of developing CVDs after influenza vaccination in RCT studies was 0.55 (95% CI 0.41–0.73), which was significant (P-value = 0.00). The pooled OR of decreasing CVDs after influenza vaccination in cohort studies was 0.89 (95% CI 0.77–1.04). The pooled OR of developing CVDs after influenza vaccination by pooling case–control studies was 0.70 (95% CI 0.57–0.86, (P-value = 0.00). All of these studies suggest decreased risks of CVDs with influenza vaccination. The current study does support the protective role of influenza vaccination on CVDs events. Health authorities may develop evidence-based preventive strategies to offer influenza vaccination in patients with CVDs.

The role of angiotensin-converting enzyme 2 in coronaviruses/influenza viruses and cardiovascular disease

Angiotensin-converting enzyme 2 (ACE2) has emerged as a key regulator of the renin–angiotensin system in cardiovascular (CV) disease and plays a pivotal role in infections by coronaviruses and influenza viruses. The present review is primarily focused on the findings to indicate the role of ACE2 in the relationship of coronaviruses and influenza viruses to CV disease. It is postulated that the risk of coronavirus or influenza virus infection is high, at least partly due to high ACE2 expression in populations with a high CV risk. Coronavirus and influenza virus vaccine usage in high CV risk populations could be a potential strategy to prevent both CV disease and coronavirus/influenza virus infections.

Relationship between Influenza Vaccination Coverage Rate and COVID-19 Outbreak: An Italian Ecological Study

Background: The lack of specific vaccines or drugs against coronavirus disease 2019 (COVID-19) warrants studies focusing on alternative clinical approaches to reduce the spread of this pandemic disease. In this study, we investigated whether anti-influenza vaccination plays a role in minimizing the diffusion of COVID-19 in the Italian population aged 65 and over. Methods: Four COVID-19 outcomes were used: severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence, hospitalizations for COVID-19 symptoms, admissions to intensive care units for reasons related to SARS-CoV-2, and deaths attributable to COVID-19. Results: At univariate analyses, the influenza vaccination coverage rates correlated negatively with all COVID-19 outcomes (Beta ranging from -134 to -0.61; all p < 0.01). At multivariable analyses, influenza vaccination coverage rates correlated independently with SARS-CoV-2 seroprevalence (Beta (95% C.I.): -130 (-198, -62); p = 0.001), hospitalizations for COVID-19 symptoms (Beta (95% C.I.): -4.16 (-6.27, -2.05); p = 0.001), admission to intensive care units for reasons related to SARS-CoV-2 (Beta (95% C.I.): -0.58 (-1.05, -0.12); p = 0.017), and number of deaths attributable to COVID-19 (Beta (95% C.I.): -3.29 (-5.66, -0.93); p = 0.010). The R2 observed in the unadjusted analysis increased from 82% to 159% for all the considered outcomes after multivariable analyses. Conclusions: In the Italian population, the coverage rate of the influenza vaccination in people aged 65 and over is associated with a reduced spread and a less severe clinical expression of COVID-19. This finding warrants ad hoc studies to investigate the role of influenza vaccination in preventing the spread of COVID-19.