Risk of hospitalization during influenza season among a cohort of patients with congestive heart failure

Pneumococcal and Influenza Vaccination Coverage in Patients with Heart Failure: A Systematic Review

Background/Objectives: As heart failure (HF) patients face increased vulnerability to respiratory infections, optimizing pneumococcal and influenza vaccination coverage becomes pivotal for mitigating additional health risks and reducing hospitalizations, morbidity, and mortality rates within this population. In this specific subpopulation of patients, vaccination coverage for pneumococcal and influenza holds heightened significance compared to other vaccines due to their susceptibility to respiratory infections, which can exacerbate existing cardiovascular conditions and lead to severe complications or even death. However, despite the recognized benefits, vaccination coverage among HF patients remains below expectations. The aim of the present systematic review was to assess the vaccination coverage for influenza and pneumococcus in HF patients from 2005 to 2023 and the vaccination's effects on survival and hospitalizations. Methods: The authors developed the protocol of the review in accordance with the PRISMA guidelines, and the search was performed in databases including PubMed and Scopus. After the initial search, 851 studies were found in PubMed Library and 1961 in Scopus (total of 2812 studies). Results: After the initial evaluation, 23 publications were finally included in the analysis. The total study population consisted of 6,093,497 participants. Regarding the influenza vaccine, vaccination coverage ranged from low rates of 2.5% to very high rates of 97%, while the respective pneumococcal vaccination coverage ranged from 20% to 84.6%. Most studies demonstrated a beneficial effect of vaccination on survival and hospitalizations. Conclusions: The present systematic review study showed a wide variety of vaccination coverage among patients with heart failure.

Temporal Association Among Influenza-Like Illness, Cardiovascular Events, and Vaccine Dose in Patients With High-Risk Cardiovascular Disease: Secondary Analysis of a Randomized Clinical Trial

Importance

Influenza-like illness (ILI) activity has been associated with increased risk of cardiopulmonary (CP) events during the influenza season. High-dose trivalent influenza vaccine was not superior to standard-dose quadrivalent vaccine for reducing these events in patients with high-risk cardiovascular (CV) disease in the Influenza Vaccine to Effectively Stop Cardio Thoracic Events and Decompensated Heart Failure (INVESTED) trial.

Objective

To evaluate whether high-dose trivalent influenza vaccination is associated with benefit over standard-dose quadrivalent vaccination in reducing CP events during periods of high, local influenza activity.

Design, Setting, and Participants

This study was a prespecified secondary analysis of INVESTED, a multicenter, double-blind, active comparator randomized clinical trial conducted over 3 consecutive influenza seasons from September 2016 to July 2019. Follow-up was completed in July 2019, and data were analyzed from September 21, 2016, to July 31, 2019. Weekly Centers for Disease Control and Prevention (CDC)-reported, state-level ILI activity was ascertained to assess the weekly odds of the primary outcome. The study population included 3094 patients with high-risk CV disease from participating centers in the US.

Intervention

Participants were randomized to high-dose trivalent or standard-dose quadrivalent influenza vaccine and revaccinated for up to 3 seasons.

Main Outcomes and Measures

The primary outcome was the time to composite of all-cause death or CP hospitalization within each season. Additional measures included weekly CDC-reported ILI activity data by state.

Results

Among 3094 participants (mean [SD] age, 65 [12] years; 2309 male [75%]), we analyzed 129 285 person-weeks of enrollment, including 1396 composite primary outcome events (1278 CP hospitalization, 118 deaths). A 1% ILI increase in the prior week was associated with an increased risk in the primary outcome (odds ratio [OR], 1.14; 95% CI, 1.07-1.21; P < .001), CP hospitalization (OR, 1.13; 95% CI, 1.06-1.21; P < .001), and CV hospitalization (OR, 1.12; 95% CI, 1.04-1.19; P = .001), after adjusting for state, demographic characteristics, enrollment strata, and CV risk factors. Increased ILI activity was not associated with all-cause death (OR, 1.00; 95% CI, 0.88-1.13; P > .99). High-dose compared with standard-dose vaccine did not significantly reduce the primary outcome, even when the analysis was restricted to weeks of high ILI activity (OR, 0.88; 95% CI, 0.65-1.20; P = .43). Traditionally warmer months in the US were associated with lower CV risk independent of local ILI activity.

Conclusions and Relevance

In this secondary analysis of a randomized clinical trial, ILI activity was temporally associated with increased CP events in patients with high-risk CV disease, and a higher influenza vaccine dose did not significantly reduce temporal CV risk. Other seasonal factors may play a role in the coincident high rates of ILI and CV events.

Trial Registration

ClinicalTrials.gov Identifier: NCT02787044.

Influenza and cardiovascular disease pathophysiology: strings attached

A link between influenza infection and cardiovascular morbidity has been known for almost a century. This narrative review examined the cardiovascular complications associated with influenza and the potential mechanisms behind this relationship. The most common reported cardiovascular complications are cardiovascular death, myocardial infarction, and heart failure hospitalization. There are multiple proposed mechanisms driving the increased risk of cardiovascular complications. These mechanics involve influenza-specific effects such as direct cardiac infection and endothelial dysfunction leading to plaque destabilization and rupture, but also hypoxaemia and systemic inflammatory responses including increased metabolic demand, biomechanical stress, and hypercoagulability. The significance of the individual effects is unclear, and thus whether influenza directly or indirectly causes cardiovascular events is unknown. In conclusion, the risk of acute cardiovascular morbidity and mortality is elevated during influenza infection. The proposed underlying pathophysiological mechanisms support this association, but systemic responses to infection may drive this relationship.

Effects of atrial fibrillation on outcomes of influenza hospitalization

Background

There is little information available on AF and its association with outcomes in adult influenza hospitalizations.

Methods

The National Inpatient Sample was queried from years 2009–2018 to create a cohort of discharges containing an influenza diagnosis. AF was the primary exposure. Univariate and multivariate regression analysis was used to describe the association of AF with clinical and healthcare-resource outcomes. Finally, a doubly-robust analysis using average treatment effect on the treated (ATT) propensity score weighting was performed to verify the results of traditional regression analysis.

Results

After adjustment, the presence of AF during influenza hospitalization was associated with higher odds of in-hospital mortality (aOR 1.56, 95 % CI 1.49 – 1.65), acute respiratory failure (aOR 1.22, 95 % CI 1.19 – 1.25), acute respiratory failure with mechanical ventilation (aOR 1.37, 95 % CI 1.32 – 1.41), acute kidney injury (aOR 1.09, 95 % CI 1.06 – 1.12), acute kidney injury requiring dialysis (aOR 1.61, 95 % CI 1.46 – 1.78) and cardiogenic shock (aOR 1.90, 95 % CI 1.65 – 2.20, all p-values < 0.0001). These findings were validated in our propensity score analysis using ATT weights. The presence of AF was also associated with higher total charges and costs of hospitalization, as well as a significantly longer length of stay (all p-values < 0.0001).

Conclusion

AF is a cardiovascular comorbidity associated with worse clinical and healthcare resource outcomes in influenza requiring hospitalization. Its presence should be used to identify patients with influenza at risk of worse prognosis.

Heart Failure after Laboratory Confirmed Influenza Infection (FLU-HF)

Background:

Influenza has been shown to exacerbate heart failure (HF). Importantly, no study to date has examined the relationship between HF hospitalizations (HFH) with laboratory confirmed influenza infections. This study evaluated the association between laboratory confirmed influenza infection and HFH in the two largest hospitals in Saskatchewan, Canada.

Methods:

We used a retrospective self-controlled case series design to evaluate the association between laboratory-confirmed influenza infection and HFH. We compared the incidence ratio for HFH during the influenza risk interval with the control interval. We defined the influenza risk interval as the seven days after a laboratory confirmed influenza result and the control interval as one year before and after the risk interval.

Results:

We identified 114 HFH that occurred within one year before and after a positive test result for influenza between April 1, 2010, and April 30, 2018. Of these, 28 (28 admissions per week) occurred during the risk interval and 86 (0.853 admissions per week) occurred during the control interval. The incidence ratio of a HFH during the risk interval as compared with the control interval was 33.53 (95% confidence interval [CI], 21.89 to 51.36). A decline in incidence was observed after day seven; between days 8 to 14 and 14 to 28 incidence ratios was 0.91 (95% CI, 0.13 to 6.52) and 0.91 (95% CI, 0.22 to 3.68) respectively.

Conclusion:

We have observed a significant association between acute influenza infection and HFH. However, further research with a larger sample size and involving a multicenter setting is warranted.

Highlights

Vaccination and modern management of chronic obstructive pulmonary disease - a narrative review

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) carries a tremendous societal and individual burden, posing significant challenges for public health systems worldwide due to its high morbidity and mortality. Due to aging and multimorbidity but also in the wake of important progress in deciphering the heterogeneous disease endotypes, an individualized approach to the prevention and management of COPD is necessary.

AREAS COVERED

This article tackles relevant immunization strategies that are available or still under development with a focus on the latest evidence but also controversies around different regional immunization approaches. Further, we present the crossover between chronic lung inflammation and lung microbiome disturbance as well as its role in delineating COPD endotypes. Moreover, the article attempts to underline endotype-specific treatment approaches. Lastly, we highlight non-pharmacologic prevention and management programs in view of the challenges and opportunities of the COVID-19 era.

EXPERT OPINION

Despite the remaining challenges, personalized medicine has the potential to offer tailored approaches to prevention and therapy and promises to improve the care of patients living with COPD.

Heart Failure Relapses in Response to Acute Stresses - Role of Immunological and Inflammatory Pathways

Cardiovascular diseases continue to be the most imminent health care problems in the western world, accounting for numerous deaths per year. Heart failure (HF), namely the reduction of left ventricular function, is one of the major cardiovascular disease entities. It is chronically progressing with relapsing acute decompensations and an overall grave prognosis that is little different if not worse than most malignant diseases. Interestingly acute metabolically and/or immunologically challenging events like infections or major surgical procedures will cause relapses in the course of preexisting chronic heart failure, decrease the patients wellbeing and worsen myocardial function. HF itself and or its progression has been demonstrated to be driven at least in part by inflammatory pathways that are similarly turned on by infectious or non-infectious stress responses. These thus add to HF progression or relapse. TNF-α plasma levels are associated with disease severity and progression in HF. In addition, several cytokines (e.g., IL-1β, IL-6) are involved in deteriorating left ventricular function. Those observations are based on clinical studies using inhibitors of cytokines or their receptors or they stem from animal studies examining the effect of cytokine mediated inflammation on myocardial remodeling in models of heart failure. This short review summarizes the known underlying immunological processes that are shared by and drive all: chronic heart failure, select infectious diseases, and inflammatory stress responses. In conclusion the text provides a brief summary of the current development in immunomodulatory therapies for HF and their overlap with treatments of other disease entities.

Prognosis of Laboratory-Confirmed Influenza and Respiratory Syncytial Virus in Acute Heart Failure

Concomitant respiratory viral infections may influence clinical outcomes of acute decompensated heart failure (ADHF) but this association is based on indirect observation. The aim of this study was to evaluate the prevalence and impact of laboratory-confirmed influenza or respiratory syncytial virus (RSV) infection on outcomes in patients hospitalised for ADHF. Prospective cohort of patients hospitalised for ADHF with systematic influenza and RSV screening using real-time PCR on nasopharyngeal swabs. The primary outcome was all-cause mortality or readmission at 90 days. Among 803 patients with ADHF, 196 (24.5%) patients had concomitant flu-like symptoms of influenza. PCR was positive in 45 patients (27 for influenza, 19 for RSV). At 90 days, PCR positive patients had lower rates of all-cause mortality or readmission as compared to patients without flu-like symptoms (HR 0.40, 95% CI 0.18–0.91, p = 0.03), and non-significantly less all-cause mortality (HR 0.30, 95% CI 0.04–2.20, p = 0.24), or HF-related death or readmission (HR 0.36, 95% CI 0.13–0.99, p = 0.05). The prevalence of influenza or RSV infection in patients admitted for ADHF was low and associated with less all-cause mortality and readmission. Concomitant viral infection with ADHF may not in itself be a predictor of poor outcomes. (ClinicalTrials.gov NCT02444416).

Vaccination for Respiratory Infections in Patients with Heart Failure

Bronchopulmonary infections are a major trigger of cardiac decompensation and are frequently associated with hospitalizations in patients with heart failure (HF). Adverse cardiac effects associated with respiratory infections, more specifically Streptococcus pneumoniae and influenza infections, are the consequence of inflammatory processes and thrombotic events. For both influenza and pneumococcal vaccinations, large multicenter randomized clinical trials are needed to evaluate their efficacy in preventing cardiovascular events, especially in HF patients. No study to date has evaluated the protective effect of the COVID-19 vaccine in patients with HF. Different guidelines recommend annual influenza vaccination for patients with established cardiovascular disease and also recommend pneumococcal vaccination in patients with HF. The Heart Failure group of the French Society of Cardiology recently strongly recommended vaccination against COVID-19 in HF patients. Nevertheless, the implementation of vaccination recommendations against respiratory infections in HF patients remains suboptimal. This suggests that a national health policy is needed to improve vaccination coverage, involving not only the general practitioner, but also other health providers, such as cardiologists, nurses, and pharmacists. This review first summarizes the pathophysiology of the interrelationships between inflammation, infection, and HF. Then, we describe the current clinical knowledge concerning the protective effect of vaccines against respiratory diseases (influenza, pneumococcal infection, and COVID-19) in patients with HF and finally we propose how vaccination coverage could be improved in these patients.

Telemedicine in Heart Failure During COVID-19: A Step Into the Future

During the Coronavirus Disease 2019 worldwide pandemic, patients with heart failure are a high-risk group with potential higher mortality if infected. Although lockdown represents a solution to prevent viral spreading, it endangers regular follow-up visits and precludes direct medical assessment in order to detect heart failure progression and optimize treatment. Furthermore, lifestyle changes during quarantine may trigger heart failure decompensations. During the pandemic, a paradoxical reduction of heart failure hospitalization rates was observed, supposedly caused by patient reluctance to visit emergency departments and hospitals. This may result in an increased patient mortality and/or in more complicated heart failure admissions in the future. In this scenario, different telemedicine strategies can be implemented to ensure continuity of care to patients with heart failure. Patients at home can be monitored through dedicated apps, telephone calls, or devices. Virtual visits and forward triage screen the patients with signs or symptoms of decompensated heart failure. In-hospital care may benefit from remote communication platforms. After discharge, patients may undergo remote follow-up or telerehabilitation to prevent early readmissions. This review provides a comprehensive appraisal of the many possible applications of telemedicine for patients with heart failure during Coronavirus disease 2019 and elucidates practical limitations and challenges regarding specific telemedicine modalities.

Coronavirus Disease 2019 (COVID-19) and its implications for cardiovascular care: expert document from the German Cardiac Society and the World Heart Federation

Coronavirus diseases 2019 (COVID-19) has become a worldwide pandemic affecting people at high risk and particularly at advanced age, cardiovascular and pulmonary disease. As cardiovascular patients are at high risk but also have dyspnea and fatigue as leading symptoms, prevention, diagnostics and treatment in these patients are important to provide adequate care for those with or without COVID-19 but most importantly when comorbid cardiovascular conditions are present. Severe COVID-19 with acute respiratory distress (ARDS) is challenging as patients with elevated myocardial markers such as troponin are at enhanced high risk for fatal outcomes. As angiotensin-converting enzyme 2 (ACE2) is regarded as the viral receptor for cell entry and as the Coronavirus is downregulating this enzyme, which provides cardiovascular and pulmonary protection, there is ongoing discussions on whether treatment with cardiovascular drugs, which upregulate the viral receptor ACE2 should be modified. As most of the COVID-19 patients have cardiovascular comorbidities like hypertension, diabetes, coronary artery disease and heart failure, which imposes a high risk on these patients, cardiovascular therapy should not be modified or even withdrawn. As cardiac injury is a common feature of COVID-19 associated ARDS and is linked with poor outcomes, swift diagnostic management and specialist care of cardiovascular patients in the area of COVID-19 is of particular importance and deserves special attention.

Adverse effects of non-steroidal anti-inflammatory drugs in patients with viral respiratory infections: rapid systematic review

OBJECTIVES

To assess the effects of non-steroidal anti-inflammatory drugs (NSAIDs) in patients with viral respiratory infections on acute severe adverse outcomes, healthcare utilisation, quality of life and long-term survival.

DESIGN

Rapid systematic review.

PARTICIPANTS

Humans with viral respiratory infections, exposed to systemic NSAIDs.

PRIMARY OUTCOMES

Acute severe adverse outcomes, healthcare utilisation, quality of life and long-term survival.

RESULTS

We screened 10 999 titles and abstracts and 738 full texts, including 87 studies. No studies addressed COVID-19, Severe Acute Respiratory Syndrome or Middle East Respiratory Syndrome; none examined inpatient healthcare utilisation, quality of life or long-term survival. Effects of NSAIDs on mortality and cardiovascular events in adults with viral respiratory infections are unclear (three observational studies; very low certainty). Children with empyema and gastrointestinal bleeding may be more likely to have taken NSAIDs than children without these conditions (two observational studies; very low certainty). In patients aged 3 years and older with acute respiratory infections, ibuprofen is associated with a higher rate of reconsultations with general practitioners than paracetamol (one randomised controlled trial (RCT); low certainty). The difference in death from all causes and hospitalisation for renal failure and anaphylaxis between children with fever receiving ibuprofen versus paracetamol is likely to be less than 1 per 10 000 (1 RCT; moderate/high certainty). Twenty-eight studies in adults and 42 studies in children report adverse event counts. Most report that no severe adverse events occurred. Due to methodological limitations of adverse event counts, this evidence should be interpreted with caution.

CONCLUSIONS

It is unclear whether the use of NSAIDs increases the risk of severe adverse outcomes in patients with viral respiratory infections. This absence of evidence should not be interpreted as evidence for the absence of such risk. This is a rapid review with a number of limitations.

PROSPERO REGISTRATION NUMBER

CRD42020176056.

The impact of influenza vaccination in patients with cardiovascular disease: An overview of systematic reviews

Whether influenza vaccination can play a prognostic role in patients with cardiovascular (CV) disease (coronary artery disease (CAD), heart failure, stroke, peripheral artery disease (PAD)) is still not completely well-established. We conducted this overview of systematic reviews (SR) evaluating the effects of influenza vaccination in secondary prevention of CV disease. An electronic search was performed in the MEDLINE (to November 2019). Eligibility criteria included SR evaluating the effect of influenza vaccination in patients with CV disease. The risk of bias of the included systematic reviews was evaluated using the ROBIS tool. All-cause mortality, CV mortality, major adverse cardiovascular events (MACE) and hospitalizations were evaluated. Whenever required, data were recalculated through a random-effects meta-analysis to obtain pooled data for the patients at secondary CV prevention. The search process yielded four SR: two in CAD, one in heart failure and one in stroke. There were no SR evaluating the vaccine in PAD. The risk of bias was unclear (2 SR) and high (2 SR). Influenza vaccination in patients with CAD showed a risk reduction in all-cause mortality (data recalculated), cardiovascular mortality and MACE, particularly in patients with recent acute coronary syndrome. In patients with heart failure, vaccination was associated with a decreased risk of all-cause mortality. There was a non-significant trend in recurrent stroke risk reduction in patients with previous stroke. The available evidence suggests that influenza vaccination was associated with a protective effect in CAD and HF patients. However, these results need to be clarified with higher quality evidence studies.

Association of Influenza-like Illness Activity With Hospitalizations for Heart Failure: The Atherosclerosis Risk in Communities Study

Importance

Influenza is associated with an increased risk of cardiovascular events, but to our knowledge, few studies have explored the temporal association between influenza activity and hospitalizations, especially those caused by heart failure (HF).

Objective

To explore the temporal association between influenza activity and hospitalizations due to HF and myocardial infarction (MI). We hypothesized that increased influenza activity would be associated with an increase in hospitalizations for HF and MI among adults in the community.

Design, Setting, and Participants

As part of the community surveillance component of the Atherosclerosis Risk in Communities (ARIC) study, a population-based study with hospitalizations sampled from 4 US communities, data were collected from 451 588 adults aged 35 to 84 years residing in the ARIC communities from annual cross-sectional stratified random samples of hospitalizations during October 2010 to September 2014.

Exposures

Monthly influenza activity, defined as the percentage of patient visits to sentinel clinicians for influenza-like illness by state, as reported by the Centers for Disease Control and Prevention Surveillance Network.

Main Outcomes and Measures

The monthly frequency of MI hospitalizations (n = 3541) and HF hospitalizations (n = 4321), collected through community surveillance and adjudicated as part of the ARIC Study.

Results

Between October 2010 and September 2014, 2042 (47.3%) and 1599 (45.1%) of the sampled patients who were hospitalized for HF and MI, respectively, were women and 2391 (53.3%) and 2013 (57.4%) were white, respectively. A 5% monthly absolute increase in influenza activity was associated with a 24% increase in HF hospitalization rates, standardized to the total population in each community, within the same month after adjusting for region, season, race/ethnicity, sex, age, and number of MI/HF hospitalizations from the month before (incidence rate ratio, 1.24; 95% CI, 1.11-1.38; P < .001), while overall influenza activity was not significantly associated with MI hospitalizations (incidence rate ratio, 1.02; 95% CI, 0.90-1.17; P = .72). Influenza activity in the months before hospitalization was not associated with either outcome. Our model suggests that in a month with high influenza activity, approximately 19% of HF hospitalizations (95% CI, 10%-28%) could be attributable to influenza.

Conclusions and Relevance

Influenza activity was temporally associated with an increase in HF hospitalizations across 4 influenza seasons. These data suggest that influenza may contribute to the risk of HF hospitalization in the general population.

Influenza Vaccine in Heart Failure

BACKGROUND

Influenza infection is a serious event for patients with heart failure (HF). Little knowledge exists about the association between influenza vaccination and outcome in patients with HF. This study sought to determine whether influenza vaccination is associated with improved long-term survival in patients with newly diagnosed HF.

METHODS

We performed a nationwide cohort study including all patients who were >18 years of age and diagnosed with HF in Denmark in the period of January 1, 2003, to June 1, 2015 (n=134 048). We collected linked data using nationwide registries. Vaccination status, number, and frequency during follow-up were treated as time-varying covariates in time-dependent Cox regression.

RESULTS

Follow-up was 99.8% with a median follow-up time of 3.7 years (interquartile range, 1.7-6.8 years). The vaccination coverage of the study cohort ranged from 16% to 54% during the study period. In unadjusted analysis, receiving ≥1 vaccinations during follow-up was associated with a higher risk of death. After adjustment for inclusion date, comorbidities, medications, household income, and education level, receiving ≥1 vaccinations was associated with an 18% reduced risk of death (all-cause: hazard ratio, 0.82; 95% CI, 0.81-0.84; P<0.001; cardiovascular causes: hazard ratio, 0.82; 95% CI, 0.81-0.84; P<0.001). Annual vaccination, vaccination early in the year (September to October), and greater cumulative number of vaccinations were associated with larger reductions in the risk of death compared with intermittent vaccination.

CONCLUSIONS

In patients with HF, influenza vaccination was associated with a reduced risk of both all-cause and cardiovascular death after extensive adjustment for confounders. Frequent vaccination and vaccination earlier in the year were associated with larger reductions in the risk of death compared with intermittent and late vaccination.

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

Objective

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.

Methods

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 I2 statistics.

Results

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; I2=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.

Conclusions

Influenza vaccination was associated with a significant decrease in all-cause mortality risk in patients with HF.

Influenza: overview on prevention and therapy

Quadrivalent influenza vaccination is recommended annually for adults and children aged six months to 64 years

High-dose or adjuvanted trivalent vaccines are recommended annually for people 65 years and over

If started early enough neuraminidase inhibitors reduce symptom duration by approximately one day Treatment should be considered in patients with severe disease requiring hospitalisation or who are at risk of complications

Chemoprophylaxis is not a substitute for vaccination but can be considered in high-risk individuals with an inadequate or ineffective vaccination status

Readmissions in adult patients following hospitalization for influenza: a nationwide cohort study

Background

Influenza epidemics are a major health care concern in the US. Influenza related complications can increase in-hospital complications, and readmissions following a hospitalization for influenza. We sought to determine the 30-day readmission rate, etiologies, outcomes, and healthcare burden of 30-day readmissions in adults hospitalized for influenza.

Methods

The 2014 US National Readmissions Database (NRD) was retrospectively analyzed to identify patients ≥18 years of age hospitalized for influenza and discharged between January and November 2014. We used this time frame as this was the most recent data available for analysis and included patients who had 30-day follow-up. Survey design based multivariable logistic regression models were used to identify factors associated with a 30-day readmission.

Results

Of the 46,117 patients who were hospitalized for influenza and survived to discharge, 4,721 (10.2%) patients had 5,275 30-day readmissions, estimated to 11.4 readmissions per 100 patients. Non-influenza pneumonia was the most common etiology of 30-day readmissions (10.4%) followed by sepsis (9.8%). The median costs of readmissions were $8,538 (IQR, $5,053-15,262), which were significantly higher than the median costs of their index hospitalizations [$7,863 (IQR, $4,875-13,212); P<0.001]. Around 6.5% of the patients died during a readmission.

Conclusions

Adult patients hospitalized for influenza had 11.4 30-day readmissions per 100 patients, most commonly for non-influenza pneumonia. Thirty-day readmissions were associated with higher costs of care and considerable mortality.

Influenza infection and heart failure-vaccination may change heart failure prognosis?

The interaction of influenza infection with the pathogenesis of acute heart failure (AHF) and the worsening of chronic heart failure (CHF) is rather complex. The deleterious effects of influenza infection on AHF/CHF can be attenuated by specific immunization. Our review aimed to summarize the efficacy, effectiveness, safety, and dosage of anti-influenza vaccination in HF. In this literature review, we searched MEDLINE and EMBASE from January 1st 1966 to December 31st, 2016, for studies examining the association between AHF/CHF, influenza infections, and anti-influenza immunizations. We used broad criteria to increase the sensitivity of the search. HF was a prerequisite for our search. The search fields used included “heart failure,” “vaccination,” “influenza,” “immunization” along with variants of these terms. No restrictions on the type of study design were applied. The most common clinical scenario is exacerbation of pre-existing CHF by influenza infection. Scarce evidence supports a potential positive association of influenza infection with AHF. Vaccinated patients with pre-existing CHF have reduced all-cause morbidity and mortality, but effects are not consistently documented. Immunization with higher antigen quantity may confer additional protection, but such aggressive approach has not been generally advocated. Further studies are needed to delineate the role of influenza infection on AHF/CHF pathogenesis and maintenance. Annual anti-influenza vaccination appears to be an effective measure for secondary prevention in HF. Better immunization strategies and more efficacious vaccines are urgently necessary.

Influenza-Associated Hospitalizations for Cardiovascular Diseases in the Tropics

Influenza is a major cause of mortality and morbidity. We aimed to examine the influenza-associated hospitalization rates and proportions for cardiovascular disease (CVD) in tropical Singapore. Hospital admissions for ischemic heart disease (IHD), congestive heart failure (CHF), and overall CVD were obtained from the national inpatient database for the period of 2010-2014. We used, as the key indicator of influenza virus activity, the overall proportion of specimens from outpatients with influenza-like illness in the community that tested positive for influenza as part of the national influenza surveillance program. The annual influenza-associated hospitalization rates per 100,000 person-years ranged from 9.5 to 12.2 for IHD, 7.7 to 9.1 for CHF, and 15.8 to 19.2 for overall CVD. The influenza-associated hospitalization rates increased with increasing age. Influenza was significantly associated with excess hospitalizations in elderly persons aged ≥80 years, with an excess hospitalization rate per 100,000 person-years of 242.7 for IHD (P = 0.02), 271.8 for CHF (P = 0.01), and 497.2 for overall CVD (P < 0.001). In the tropics, influenza accounts for excess cardiovascular-related hospitalizations, especially in the elderly.

Increased risk of influenza among vaccinated adults who are obese

Background

Influenza infects 5–15% of the global population each year, and obesity has been shown to be an independent risk factor for increased influenza-related complications including hospitalization and death. However, the risk of developing influenza or ILI in a vaccinated obese adult population has not been addressed.

Objective

This study evaluated whether obesity was associated with increased risk of influenza and influenza-like illness among vaccinated adults.

Subjects and Methods

During the 2013–2014 and 2014–2015 influenza seasons, we recruited 1042 subjects to a prospective observational study of trivalent inactivated influenza vaccine (IIV3) in adults.1022 subjects completed the study. Assessments of relative risk for laboratory confirmed influenza and influenza-like illness were determined based on BMI. Seroconversion and seroprotection rates were determined using pre-vaccination and 26–35 days post-vaccination serum samples. Recruitment criteria for this study were adults 18 years of age and older receiving the seasonal trivalent inactivated influenza vaccine (IIV3) for the years 2013–2014 and 2014–2015. Exclusion criteria were immunosuppressive diseases, use of immunomodulatory or immunosuppressive drugs, acute febrile illness, history of Guillain-Barre syndrome, use of theophylline preparations, or use of warfarin.

Results

Among obese, 9.8% had either confirmed influenza or influenza-like-illness compared with 5.1% of healthy weight participants. Compared with vaccinated healthy weight, obese participants had double the risk of developing influenza or influenza-like illness (relative risk= 2.01, 95% CI 1.12, 3.60, p=0.020). Seroconversion or seroprotection rates were not different between healthy weight and obese adults with influenza or ILI.

Conclusions

Despite robust serological responses, vaccinated obese adults are twice as likely to develop influenza and influenza-like illness compared to healthy weight adults. This finding challenges the current standard for correlates of protection, suggesting use of antibody titers to determine vaccine effectiveness in an obese population may provide misleading information.

Influenza vaccination in north Indian patients with heart failure

Background

No data exists regarding the uptake of influenza vaccination in patients with heart failure (HF) in India. The present study was designed to assess the uptake, knowledge, attitude and practices of the Indian HF patients towards influenza vaccination.

Methods and results

Five-hundred patients with acute/chronic HF were approached for a personal interview and responses to an interview recorded in a pre-defined questionnaire depicting their knowledge, attitudes and practice regarding influenza vaccination. Of the 500 approached, 320 (64%, 174 male, age 3–90 years) consented to participate in the survey. Only 7.5% (n = 24) knew of influenza as an illness with adverse potential consequences for themselves or their family. Seventeen (5.3%) were aware of potentially serious nature of influenza and 40 (12.5%) knew of the availability of a vaccine against it and its local availability. However only 14 (4.4%) had actually received the vaccine 1–2 times in the past 5 years. Only 21 (6.56%) had been prescribed influenza vaccine by their respective physicians. Reasons for declining vaccination included misperceptions about safety and efficacy of the vaccine. Most of the participants, however, had not been prescribed vaccination at all.

Conclusions

Poor influenza vaccination rates in HF mandate intense efforts to improve vaccination rates.

Influenza Vaccination Reduces Hospitalization for Heart Failure in Elderly Patients with Chronic Kidney Disease: A Population-Based Cohort Study

BACKGROUND

Elderly patients with chronic kidney disease (CKD) are at a higher risk of hospitalization for cardiovascular diseases (CVD). Previous studies have reported the beneficial effects of the influenza vaccine in patients with CVD. However, the effects of influenza vaccination on the reduction of hospitalizations for heart failure (HF) in elderly patients with CKD remain unclear.

METHODS

This cohort study comprised elderly patients (≥ 55 years of age) with a recorded diagnosis of CKD (n = 4406) between January 1, 1999 and December 31, 2008. Each patient was followed-up until the end of 2008. The hazard ratio (HR) and 95% confidence interval (CI) for the association between the influenza vaccination and the first HF hospitalization were analyzed. In addition, the patients were categorized into four groups based on their vaccination status (unvaccinated and total number of vaccinations: 1, 2-3, and ≥ 4).

RESULTS

We found that elderly patients with CKD receiving influenza vaccination exhibited a lower risk of HF hospitalization (adjusted HR, 0.31; 95% CI, 0.26-0.39, p < 0.001). The protective effects of influenza vaccination remained consistent regardless of the age group (55-64, 65-74, ≥ 75), sex, and influenza seasonality. When the patients were stratified according to the total number of vaccinations, the adjusted HRs for HF hospitalization were 0.60 (0.47-0.77), 0.30 (0.23-0.41), and 0.10 (0.06-0.16) for patients who received 1, 2-3, and ≥ 4 vaccinations during the follow-up period, respectively.

CONCLUSIONS

The results revealed that elderly patients with CKD receiving annual influenza vaccination are at a lower risk of HF hospitalization.

Seasonal variation in hospital admission in patients with heart failure and its effect on prognosis

BACKGROUND

A seasonal variation in hospital admissions in patients with heart failure (HF) has been described and most admissions occur during the winter season. The effect of this seasonal variation on prognosis is less clear.

OBJECTIVES

To evaluate the effect of the seasonal timing of hospital admission on clinical outcome in patients with HF.

METHODS

We prospectively enrolled 362 consecutive patients hospitalized with a definite clinical diagnosis of HF during a 2-year period. Patients were followed clinically for a period of 1 year.

RESULTS

There was a prominent seasonal variation in hospital admissions in patients with HF with peak admissions during the winter. The admission rate inversely correlated with the average monthly temperature. Admission during the summer season was a significant predictor of reduced survival (59 vs. 75%, p < 0.01). Cox regression analysis demonstrated that independent predictors of reduced survival after adjustment for other predictors were admission during the hottest 6 months or admission during the summer. In addition, increased mean environmental admission temperature was an independent predictor of reduced survival.

CONCLUSIONS

Seasonal temperature has a significant effect on the rate of hospital admission in patients with HF. Admission during warmer weather is a sign of a poor prognosis.

The influence of heart failure self-care on health outcomes: hypothetical cardioprotective mechanisms

Lapses in self-care are commonly cited as a major cause of poor outcomes in persons with heart failure (HF). Not surprisingly, self-care is assumed to be central to improving health outcomes in this patient population. Empirically, however, this assumption is not well supported, and mechanistically, relationships between self-care and outcomes in HF have not yet been described. In this review, it is proposed that effective self-care maintenance (adherence) and self-care management (symptom evaluation and management) practices are complementary to optimal medical management in delaying HF progression and improving health outcomes in this population. Potential mechanisms through which effective HF self-care practices are complementary to pharmacological therapy in improving outcomes include (a) facilitating partial blockade and partial deactivation of deleterious neurohormones, (b) limiting inflammatory processes, (c) decreasing the need for administration of detrimental pharmacological agents, and (d) minimizing myocardial hibernation. Because these mechanisms are hypothetical, research findings are required to establish their validity. Several strategic research questions are proposed.

Alternative vaccination locations: who uses them and can they increase flu vaccination rates?

Since many unvaccinated individuals do not regularly contact the traditional health care system, we sought to determine the role that alternative vaccination locations (e.g., workplaces and retail clinics) could play in increasing influenza vaccination coverage. Between February 14, 2008 and March 10, 2008, a 25-question influenza vaccine questionnaire was administered to a nationally representative, stratified sample of panelists. Our results found that while alternative locations are covering some segments not captured by the traditional health care system (e.g., younger, working, white individuals in metropolitan areas), they are not serving many other segments (e.g., minority, rural, or lower income patients).

Cardiovascular manifestations associated with influenza virus infection

Influenza accounts for 3 to 5 million cases of severe illness and up to 300,000 deaths annually. Cardiovascular involvement in acute influenza infection can occur through direct effects of the virus on the myocardium or through exacerbation of existing cardiovascular disease. Epidemiological studies have demonstrated an association between influenza epidemics and cardiovascular mortality and a decrease in cardiovascular mortality in high risk patients has been demonstrated following vaccination with influenza vaccine. Influenza is a recognised cause of myocarditis which can lead to significant impairment of cardiac function and mortality. With recent concerns regarding another potential global pandemic of influenza the huge potential for cardiovascular morbidity and mortality is discussed.

Comparing estimates of influenza-associated hospitalization and death among adults with congestive heart failure based on how influenza season is defined

BACKGROUND

There is little consensus about how the influenza season should be defined in studies that assess influenza-attributable risk. The objective of this study was to compare estimates of influenza-associated risk in a defined clinical population using four different methods of defining the influenza season.

METHODS

Using the Studies of Left Ventricular Dysfunction (SOLVD) clinical database and national influenza surveillance data from 1986-87 to 1990-91, four definitions were used to assess influenza-associated risk: (a) three-week moving average of positive influenza isolates is at least 5%, (b) three-week moving average of positive influenza isolates is at least 10%, (c) first and last positive influenza isolate are identified, and (d) 5% of total number of positive isolates for the season are obtained. The clinical data were from adults aged 21 to 80 with physician-diagnosed congestive heart failure. All-cause hospitalization and all-cause mortality during the influenza seasons and non-influenza seasons were compared using four definitions of the influenza season. Incidence analyses and Cox regression were used to assess the effect of exposure to influenza season on all-cause hospitalization and death using all four definitions.

RESULTS

There was a higher risk of hospitalization associated with the influenza season, regardless of how the start and stop of the influenza season was defined. The adjusted risk of hospitalization was 8 to 10 percent higher during the influenza season compared to the non-influenza season when the different definitions were used. However, exposure to influenza was not consistently associated with higher risk of death when all definitions were used. When the 5% moving average and first/last positive isolate definitions were used, exposure to influenza was associated with a higher risk of death compared to non-exposure in this clinical population (adjusted hazard ratios [HR], 1.16; 95% confidence interval [CI], 1.04 to 1.29 and adjusted HR, 1.19; 95% CI, 1.06 to 1.33, respectively).

CONCLUSION

Estimates of influenza-attributable risk may vary depending on how influenza season is defined and the outcome being assessed.