Vaccination Trends in Patients With Heart Failure: Insights From Get With The Guidelines-Heart Failure

Receipt of respiratory vaccines among patients with heart failure in a multicenter health system registry

BACKGROUND

Heart failure affects people of all ages and is a leading cause of death for both men and women in most racial and ethnic groups in the United States. Infections are common causes of hospitalizations in heart failure, with respiratory infections as the most frequent diagnosis. Vaccinations provide significant protection against preventable respiratory infections. Despite being an easily accessible intervention, prior studies suggest vaccines are underused in patients with heart failure.

METHODS

An observational study of 5089 adults with heart failure was conducted using data from an integrated, multicenter, academic health system in Southern California from 2019 to 2022. Logistic regression models were used to determine the rates of influenza, pneumococcal, and COVID-19 vaccination among a population of patients with heart failure (heart failure preserved ejection fraction [HFpEF], heart failure mildly reduced ejection fraction [HFmrEF], and heart failure reduced ejection fraction [HFrEF], and identify whether heart failure phenotype is associated with vaccination status.

RESULTS

Vaccination rates varied between influenza, pneumococcal, and COVID-19 vaccines. Of the three respiratory vaccines, 58.0 % of patients had received an influenza vaccine, 76.2 % had received a pneumococcal vaccine, and 83.3 % had received a COVID-19 vaccine. There were no sex-based differences by vaccination status. Differences were seen within age, race/ethnicity, insurance type, whether the patient was a member of an Accountable Care Organization (ACO), primary language, Social Vulnerability Index (SVI) score, clinician type, and number of comorbidities. Patients with HFpEF and HFmrEF had higher vaccination rates than HFrEF. In adjusted models, patients with HFrEF had lower odds of being vaccinated for influenza (aOR = 0.75, 95 % CI = 0.66-0.86), pneumococcal (aOR = 0.65, 95 % CI = 0.55-0.75), and COVID (aOR = 0.74, 95 % CI = 0.62-0.89) compared to patients with HFpEF.

CONCLUSIONS

Patients with HFrEF had the lowest levels of respiratory vaccination compared to other specified heart failure categories. Interventions are needed to increase vaccination education and offerings, especially to patients with HFrEF.

The Impact of Vaccinations Against Respiratory Infections on the Prognosis in Heart Failure Patients

Heart failure (HF) affects 64 million people worldwide and is one of the most prevalent causes of hospitalization in adults. Infection is believed to be one of the potential triggers that may facilitate HF decompensation and the need for hospitalization. Therefore, it seems crucial to safeguard against such a situation. Vaccinations seem to be a very reasonable option. However, this remains an underutilized solution among HF patients. This review investigates the impact of available vaccinations, including influenza, COVID-19, pneumococcal, and RSV, on prognosis in specific HF populations only, as there are pathophysiological reasons to believe that this population of patients may benefit the most from the intervention. It will provide information about the safety profile of these vaccines and summarize the available evidence on their impact on hard clinical outcomes. In summary, this article will discuss the impact of preventive vaccinations against seasonal infections in the HF population.

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.

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.

Clinical Outcomes With Electronic Nudges to Increase Influenza Vaccination : A Prespecified Analysis of a Nationwide, Pragmatic, Registry-Based, Randomized Implementation Trial

BACKGROUND

In the NUDGE-FLU (Nationwide Utilization of Danish Government Electronic letter system for increasing inFLUenza vaccine uptake) trial, electronic letters incorporating cardiovascular (CV) gain-framing and repeated messaging increased influenza vaccination by approximately 1 percentage point.

OBJECTIVE

To evaluate the effects of the successful nudging interventions on downstream clinical outcomes.

DESIGN

Prespecified exploratory analysis of a nationwide randomized implementation trial. (ClinicalTrials.gov: NCT05542004).

SETTING

The 2022 to 2023 influenza season.

PARTICIPANTS

964 870 Danish citizens aged 65 years or older.

INTERVENTION

Usual care or 9 different electronically delivered behavioral nudging letters.

MEASUREMENTS

Cardiovascular, respiratory, and other clinical end points during follow-up from intervention delivery (16 September 2022) through 31 May 2023.

RESULTS

The analysis set included 691 820 participants. Hospitalization for pneumonia or influenza occurred in 3354 of 346 327 (1.0%) participants in the usual care group, 396 of 38 586 (1.0%) in the CV gain-framing group (hazard ratio [HR], 1.06 [95% CI, 0.95 to 1.18]; versus usual care), and 403 of 38 231 (1.1%) in the repeated letter group (HR, 1.09 [CI, 0.98 to 1.21]; versus usual care). In the usual care group, 44 682 (12.9%) participants were hospitalized for any cause, compared with 5002 (13.0%) in the CV gain-framing group (HR, 1.00 [CI, 0.97 to 1.03]; versus usual care) and 4965 (13.0%) in the repeated letter group (HR, 1.01 [CI, 0.98 to 1.04]; versus usual care). A total of 6341 (1.8%) participants died in the usual care group, compared with 721 (1.9%) in the CV gain-framing group (HR, 1.02 [CI, 0.94 to 1.10]; versus usual care) and 646 (1.7%) in the repeated letter group (HR, 0.92 [CI, 0.85 to 1.00]; versus usual care).

LIMITATION

Prespecified but exploratory analysis, potential misclassification of events in routinely collected registry data, and results may not be generalizable to other health systems or countries with other racial compositions and/or cultural or societal norms.

CONCLUSION

In a prespecified exploratory analysis, modest increases in influenza vaccination rates seen with electronic nudges did not translate into observable improvements in clinical outcomes. Seasonal influenza vaccination should remain strongly recommended.

PRIMARY FUNDING SOURCE

Sanofi.

Electronic nudges to increase influenza vaccination uptake among patients with heart failure: A pre-specified analysis of the NUDGE-FLU trial

AIMS

Seasonal influenza vaccination is strongly recommended in patients with heart failure (HF). The NUDGE-FLU trial recently found two electronic behavioural nudging letter strategies - a letter highlighting potential cardiovascular benefits of vaccination and a repeated letter at day 14 -effective in increasing influenza vaccination in Denmark. The aims of this pre-specified analysis was to further examine vaccination patterns and effects of these behavioural nudges in patients with HF including potential off-target effects on guideline-directed medical therapy (GDMT) use.

METHODS AND RESULTS

The nationwide NUDGE-FLU trial randomized 964 870 Danish citizens ≥65 years to usual care or nine different electronic nudging letter strategies. Letters were delivered through the official Danish electronic letter system. The primary endpoint was the receipt of an influenza vaccine; additional outcomes for this analysis included GDMT use. In this analysis, we also assessed influenza vaccination rates in the overall Danish HF population including those <65 years (n = 65 075). During the 2022-2023 season, influenza vaccination uptake was 71.6% in the overall Danish HF population but this varied considerably with only 44.6% uptake in those <65 years. A total of 33 109 NUDGE-FLU participants had HF at baseline. Vaccination uptake was higher among those on higher levels of baseline GDMT (≥3 classes: 85.3% vs. ≤2 classes: 81.9%; p < 0.001). HF status did not modify the effects of the two overall successful nudging strategies on influenza vaccination uptake (cardiovascular gain-framed letter: pinteraction  = 0.37; repeated letter: pinteraction  = 0.55). No effect modification was observed across GDMT use levels for the repeated letter (pinteraction  = 0.88), whereas a trend towards attenuated effect among those on low levels of GDMT was observed for the cardiovascular gain-framed letter (pinteraction  = 0.07). The letters had no impact on longitudinal GDMT use.

CONCLUSIONS

Approximately one in four patients with HF did not receive influenza vaccination with a pronounced implementation gap in those <65 years where less than half were vaccinated. HF status did not modify the effectiveness of cardiovascular gain-framed and repeated electronic nudging letters in increasing influenza vaccination rates. No unintended negative effects on longitudinal GDMT use were observed.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT05542004.

Nationwide Utilization of Danish Government Electronic letter system for increasing inFLUenza vaccine uptake (NUDGE-FLU): Study protocol for a nationwide randomized implementation trial

BACKGROUND

Annual influenza vaccination is widely recommended in older adults and other high-risk groups including patients with cardiovascular disease. The real-world effectiveness of influenza vaccination is limited by suboptimal uptake and effective strategies for increasing vaccination rates are therefore needed. The purpose of this trial is to investigate whether behavioral nudges digitally delivered via the Danish nationwide mandatory governmental electronic letter system can increase influenza vaccination uptake among older adults.

METHODS

The NUDGE-FLU trial is a randomized implementation trial randomizing all Danish citizens aged 65 years and above without an exemption from the Danish mandatory governmental electronic letter system to receive no digitally delivered behavioral nudge (usual care arm) or to receive one of 9 electronic letters (intervention arms) each leveraging different behavioral science strategies. The trial has randomized 964,870 participants with randomization clustered at the household level (n = 691,820 households). Intervention letters were delivered on September 16, 2022, and follow-up is currently ongoing. All trial data are captured using the nationwide Danish administrative health registries. The primary end point is the receipt of an influenza vaccine on or before January 1, 2023. The secondary end point is time to vaccination. Exploratory end points include clinical events such as hospitalization for influenza or pneumonia, cardiovascular events, all-cause hospitalization, and all-cause mortality.

DISCUSSION

The nationwide randomized NUDGE-FLU trial is one of the largest implementation trials ever conducted and will provide important insights into effective communication strategies to maximize vaccination uptake among high-risk groups.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT05542004, registered September 15, 2022, https://clinicaltrials.gov/ct2/show/NCT05542004.

Electronic nudges to increase influenza vaccination uptake in Denmark: a nationwide, pragmatic, registry-based, randomised implementation trial

BACKGROUND

Influenza vaccination rates remain suboptimal despite effectiveness in preventing influenza infection and related complications. We investigated whether behavioural nudges, delivered via a governmental electronic letter system, would increase influenza vaccination uptake among older adults in Denmark.

METHODS

We did a nationwide, pragmatic, registry-based, cluster-randomised implementation trial during the 2022-23 influenza season in Denmark. All Danish citizens aged 65 years or older or turning 65 years by Jan 15, 2023 were included. We excluded individuals living in nursing homes and individuals who had an exemption from the Danish mandatory governmental electronic letter system. Households were randomly assigned (9:1:1:1:1:1:1:1:1:1) to usual care or nine different electronic letters designed on the basis of different behavioural nudging concepts. Data were sourced from nationwide Danish administrative health registries. The primary endpoint was receipt of influenza vaccination on or before Jan 1, 2023. The primary analysis assessed an analytical set of one randomly selected individual per household, and a sensitivity analysis included all randomly assigned individuals and accounted for within-household correlation. The trial is registered with ClinicalTrials.gov, NCT05542004.

FINDINGS

We identified 1 232 938 individuals aged 65 years or older in Denmark and excluded 56 436 (4·6%) individuals living in nursing homes and 211 632 (17·2%) with an exemption from the electronic letter system. We randomly assigned 964 870 (78·3%) participants across 691 820 households. Compared with usual care, influenza vaccination rates were higher in the group receiving an electronic letter highlighting potential cardiovascular benefits of vaccination (81·00% vs 80·12%; difference 0·89 percentage points [99·55% CI 0·29-1·48]; p<0·0001) and the group receiving repeated letters at randomisation and at day 14 (80·85% vs 80·12%; difference 0·73 percentage points [0·13-1·34]; p=0·0006). These strategies improved vaccination rates across major subgroups including those with and without established cardiovascular disease. The cardiovascular gain-framed letter was particularly effective among participants who had not been vaccinated for influenza in the previous season (p_interaction=0·0002). A sensitivity analysis of all randomly assigned individuals accounting for within-household clustering yielded similar findings.

INTERPRETATION

Electronically delivered letters highlighting potential cardiovascular benefits of influenza vaccination or sent again as a reminder significantly increased vaccination uptake across Denmark. Although the magnitude of effectiveness was modest, the low-touch, inexpensive, and highly scalable nature of these electronic letters might be informative for future public health campaigns.

FUNDING

Sanofi.

Worse In-Hospital Outcomes Among Patients With Heart Failure (HF) and Concomitant Influenza Infection

INTRODUCTION

 A sizable proportion of heart failure (HF) admissions is precipitated by respiratory infections. Influenza has been linked to higher rates of HF hospitalizations and in-hospital morbidity and mortality.

AIM/OBJECTIVE

 We aim to describe the in-hospital outcomes of systolic HF vs. diastolic HF admissions with concomitant influenza infection in US hospitalizations from 2016 to 2017.  Materials and Methods: We queried the National Inpatient Sample (NIS) from 2016 to 2017 for discharge diagnosis for SHF and DHF and influenza per ICD-10 CM codes. Using binominal logistic regression analysis and adjusting for demographic and comorbid conditions, we compared the outcomes of SHF vs. DHF admissions with concomitant influenza as an independent risk factor for inpatient mortality, acute respiratory failure, ICU admission, assisted ventilation, as well as length of stay, and total hospital costs.

RESULTS

 A total of 7,490,596 HF weighted admissions were analyzed, among which 0.9% had concomitant influenza infection. SHF and DHF admissions with influenza had higher mortality, ICU admission, ventilation assistance, and acute respiratory failure when compared to those without influenza. Among influenza admissions, those with SHF had higher mortality (6.6% vs. 5%, adjusted odds ratio - aOR 1.31, p<0.001) compared to DHF. While intensive care unit (ICU) admission (7.8% vs. 5.2%, aOR 1.30, p<0.001) and ventilation assistance rates (22.1% vs. 18.9%, aOR 1.15, p<0.001) were greater among SHF patients with influenza, acute respiratory failure was more common amongst diastolic HF with influenza (46.6% vs. 51.2%, aOR 0.86, p<0.001). Finally, SHF patients with concomitant influenza had higher inpatient costs ($82,788) when compared to diastolic HF patients ($66,373) and a longer in-hospital stay (7.29 days compared to 6.98 days in the diastolic HF group) p <0.001.

CONCLUSION

 Concomitant influenza infection in hospitalized patients with HF is associated with higher mortality, ICU admission, and the need for assisted ventilation, especially in those with SHF. A greater emphasis on vaccination against influenza may improve in-patient outcomes among HF patients.

The link between influenza and myocardial infarction: vaccination protects

The association between influenza and cardiovascular disease has been known since the influenza pandemics of the early years of the last century. This association is more consistent and more lasting in the case of particularly severe infections. Several pathogens, including influenza viruses, can modulate the inflammatory response and influence the biology of atherosclerotic plaque to rupture it and cause a Type 1 myocardial infarction. Clinically relevant viral infections can also exacerbate pre-existing cardiovascular disease and contribute to the development of a Type 2 myocardial infarction through an increase in the metabolic demands of the myocardial tissue for fever and tachycardia and the possible induction of hypoxaemia. Evidence of a relevant protective efficacy of influenza vaccination provides further robust and convincing support for a causal link between influenza and myocardial infarction. Consistent cardiovascular protection linked to influenza vaccination has also been demonstrated in patients with recent myocardial infarction to suggest the possibility that this procedure may become an integral part of in-hospital management of acute coronary syndromes. Despite the solidity of these evidences, acknowledged by the guidelines that recommend influenza vaccination in patients at increased cardiovascular risk, still today an unacceptably high proportion of patients at high cardiovascular risk do not receive flu vaccination. Despite some potential limitations of the current flu vaccination, its advantages in terms of reducing cardiovascular events and related mortality are still such as to justify its wide use, especially, but not limited to, in patients with high cardiovascular risk.

Influenza vaccination and mortality among adults with heart failure in an integrated healthcare delivery system, 2009-2018

BACKGROUND

Influenza infection can result in decompensation or exacerbation of heart failure (HF) symptoms, hospitalization, and death.

OBJECTIVE

To examine the association of influenza vaccination with mortality and hospitalization during influenza and non-influenza seasons between 2009 and 2018.

DESIGN, SETTING, AND PARTICIPANTS

In this prospective, observational cohort study, we included Kaiser Permanente Southern California members with a HF diagnosis prior to September 1 each year from 2009 to 2017.

EXPOSURE

The first influenza vaccination in each season (September 1 to May 31) was recorded. Vaccinated/unvaccinated patients were matched 1:1 on age, sex, and ejection fraction at the vaccination date (n-total = 74,870).

MAIN OUTCOMES

Patients were followed through the end of each influenza season for all-cause mortality. Secondary outcomes included cardiovascular mortality and all-cause hospitalization. In a sensitivity analysis, we examined mortality in the non-influenza season.

RESULTS

Influenza vaccinated vs unvaccinated patients had more comorbidities and higher healthcare utilization. After multivariable adjustment for utilization, sociodemographics, comorbidities, and medications, influenza vaccinated vs unvaccinated patients had a lower risk of all-cause mortality and cardiovascular mortality during the influenza season (hazard ratio [HR] 0.66, 95% confidence interval [CI] 0.63, 0.70 and HR 0.68, 95% CI 0.63, 0.74, respectively) but a higher risk of all-cause hospitalization (HR 1.27, 95% CI 1.21, 1.31). There was no association between influenza vaccination and all-cause or cardiovascular mortality during the non-influenza season (HR 0.99, 95% CI 0.89, 1.09 and HR 1.00, 95% CI 0.84, 1.21, respectively).

CONCLUSIONS

Influenza vaccination in HF patients was associated with a lower risk of mortality during the influenza season. Our findings provide support for recommendations of universal influenza vaccination in patients with HF.

Effectiveness of the influenza vaccine at reducing adverse events in patients with heart failure: A systematic review and meta-analysis

BACKGROUND

The association between influenza and adverse vascular events in patients with heart failure is well documented. The effect of the influenza vaccine on preventing such adverse events is uncertain. This systematic review and meta-analysis addressed whether vaccination against influenza reduces adverse vascular events and mortality in heart failure patients.

METHODS

MEDLINE and EMBASE databases were comprehensively searched, study screening and quality assessment were completed, and data was synthesized. Eligible studies investigated heart failure patients who received the influenza vaccine, and reported outcomes within 12 months, compared to heart failure patients who did not receive the influenza vaccine. The following 6 outcomes were assessed: all-cause mortality, cardiovascular-related mortality, all-cause hospitalization, cardiovascular-related hospitalization, non-fatal myocardial infarction, and non-fatal stroke. Risk of bias was assessed using the Newcastle-Ottawa Scale and a GRADE assessment was completed. A random-effects meta-analysis was performed to estimate the pooled risk ratio (RR), 95% confidence intervals (CIs), and heterogeneity using I² statistics.

RESULTS

After synthesizing data from 7 non-randomized studies (247,842 patients), the results demonstrate the risk of all-cause mortality is significantly reduced within 12 months of a heart failure patient receiving the influenza vaccine (RR = 0.75, 95% CI 0.71-0.79; P<0.0001); very low certainty of evidence. The risk of cardiovascular-related mortality was significantly reduced (RR = 0.77, 95% CI 0.73-0.81; P<0.0001); low certainty of evidence. The pooled risk of all-cause hospitalization was higher among vaccinated heart failure patients (RR = 1.24, 95% CI 1.13-1.35; P<0.0001), based on two studies; very low certainty of evidence and considerable heterogeneity (I² = 90%). No eligible studies assessed cardiovascular-related hospitalization, non-fatal myocardial infarction, or non-fatal stroke.

CONCLUSIONS

Influenza vaccination appears to reduce adverse cardiovascular events, although the certainty of the evidence is low or very low. Rigorous randomized controlled trial evidence is needed to further examine the protective effect of the influenza vaccine in heart failure patients.

Association of Influenza Vaccination With Cardiovascular Risk: A Meta-analysis

Importance

Influenza infection is associated with increased cardiovascular hospitalization and mortality. Our prior systematic review and meta-analysis hypothesized that influenza vaccination was associated with a lower risk of cardiovascular events.

Objective

To evaluate, via an updated meta-analysis, if seasonal influenza vaccination is associated with a lower risk of fatal and nonfatal cardiovascular events and assess whether the newest cardiovascular outcome trial results are consistent with prior findings.

Data Sources

A previously published meta-analysis of randomized controlled trials (RCTs) and a large 2021 cardiovascular outcome trial.

Study Selection

Studies with RCTs published between 2000 and 2021 that randomized participants to either influenza vaccine or placebo/control. Eligible participants were inpatients and outpatients recruited for international multicenter RCTs and randomized to receive either influenza vaccine or placebo/control.

Data Extraction and Synthesis

PRISMA guidelines were followed in the extraction of study details, and risk of bias was assessed using the Cochrane Collaboration tool. Trial quality was evaluated using Cochrane criteria. Data were analyzed January 2020 and December 2021.

Main Outcomes and Measures

Random-effects Mantel-Haenszel risk ratios (RRs) and 95% CIs were derived for a composite of major adverse cardiovascular events and cardiovascular mortality within 12 months of follow-up. Where available, analyses were stratified by patients with and without recent acute coronary syndrome (ACS) within 1 year of randomization.

Results

Six published RCTs comprising a total of 9001 patients were included (mean age, 65.5 years; 42.5% women; 52.3% with a cardiac history). Overall, influenza vaccine was associated with a lower risk of composite cardiovascular events (3.6% vs 5.4%; RR, 0.66; 95% CI, 0.53-0.83; P < .001). A treatment interaction was detected between patients with recent ACS (RR, 0.55; 95% CI, 0.41-0.75) and without recent ACS (RR, 1.00; 95% CI, 0.68-1.47) (P for interaction = .02). For cardiovascular mortality, a treatment interaction was also detected between patients with recent ACS (RR, 0.44; 95% CI, 0.23-0.85) and without recent ACS (RR, 1.45; 95% CI, 0.84-2.50) (P for interaction = .006), while 1.7% of vaccine recipients died of cardiovascular causes compared with 2.5% of placebo or control recipients (RR, 0.74; 95% CI, 0.42-1.30; P = .29).

Conclusions and Relevance

In this study, receipt of influenza vaccination was associated with a 34% lower risk of major adverse cardiovascular events, and individuals with recent ACS had a 45% lower risk. Given influenza poses a threat to population health during the COVID-19 pandemic, it is integral to counsel high-risk patients on the cardiovascular benefits of influenza vaccination.

Acute Bacterial Infections and Longitudinal Risk of Readmissions and Mortality in Patients Hospitalized with Heart Failure

Aims: Infections are associated with worse short-term outcomes in patients with heart failure (HF). However, acute infections may have lasting pathophysiologic effects that adversely influence HF outcomes after discharge. Our objective was to describe the impact of acute bacterial infections on longitudinal outcomes of patients hospitalized with a primary diagnosis of HF. Methods and Results: This paper is based on a retrospective cohort study of patients hospitalized with a primary diagnosis of HF with or without a secondary diagnosis of acute bacterial infection in Optum Clinformatics DataMart from 2010–2015. Primary outcomes were 30 and 180-day hospital readmissions and mortality, intensive care unit admission, length of hospital stay, and total hospital charge, compared between those with or without an acute infection. Cohorts were compared after inverse probability of treatment weighting. Multivariable logistic regression was used to examine relationship to outcomes. Of 121,783 patients hospitalized with a primary diagnosis of HF, 27,947 (23%) had a diagnosis of acute infection. After weighting, 30-day hospital readmissions [17.1% vs. 15.7%, OR 1.11 (1.07–1.15), p < 0.001] and 180-day hospital readmissions [39.6% vs. 38.7%, OR 1.04 (1.01–1.07), p = 0.006] were modestly greater in those with an acute infection versus those without. Thirty-day [5.5% vs. 4.3%, OR 1.29 (1.21–1.38), p < 0.001] and 180-day mortality [10.7% vs. 9.4%, OR 1.16 (1.11–1.22), p < 0.001], length of stay (7.1 ± 7.0 days vs. 5.7 ± 5.8 days, p < 0.001), and total hospital charges (USD 62,200 ± 770 vs. USD 51,100 ± 436, p < 0.001) were higher in patients with an infection. Conclusions: The development of an acute bacterial infection in patients hospitalized for HF was associated with an increase in morbidity and mortality after discharge.

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.

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

The link between viral respiratory infection and non-pulmonary organ-specific injury, including cardiac injury, has become increasingly appreciated during the current coronavirus disease 2019 (COVID-19) pandemic. Even prior to the pandemic, however, the association between acute infection with influenza and elevated cardiovascular risk was evident. The recently published results of the NHLBI-funded INfluenza Vaccine to Effectively Stop CardioThoracic Events and Decompensated (INVESTED) trial, a 5200 patient comparative effectiveness study of high-dose vs. standard-dose influenza vaccine to reduce cardiopulmonary events and mortality in a high-risk cardiovascular population, found no difference between strategies. However, the broader implications of influenza vaccine as a strategy to reduce morbidity in high-risk patients remain extremely important, with randomized controlled trial and observational data supporting vaccination in high-risk patients with cardiovascular disease. Given a favourable risk-benefit profile and widespread availability at generally low cost, we contend that influenza vaccination should remain a centrepiece of cardiovascular risk mitigation and describe the broader context of underutilization of this strategy. Few therapeutics in medicine offer seasonal efficacy from a single administration with generally mild, transient side effects, and exceedingly low rates of serious adverse effects. Infection control measures such as physical distancing, hand washing, and the use of masks during the COVID-19 pandemic have already been associated with substantially curtailed incidence of influenza outbreaks across the globe. Appending annual influenza vaccination to these measures represents an important public health and moral imperative.

Influenza-associated cardiovascular mortality in older adults in Beijing, China: a population-based time-series study

OBJECTIVE

This study comprehensively estimated the excess cardiovascular disease (CVD) mortality attributable to influenza in an older (age ≥65 years) population.

DESIGN

Ecological study.

SETTING

Aggregated data from administrative systems on CVD mortality, influenza surveillance and meteorological data in Beijing, China.

MAIN OUTCOME MEASURE

Excess overall CVD, and separately for ischaemic heart disease (IHD), ischaemic stroke, haemorrhagic stroke mortality attributable to influenza, adjusting for influenza activity, time trend, seasonality and ambient temperature.

RESULTS

CVD (risk ratio (RR) 1.02, 95% CI 1.01, 1.02), IHD (RR 1.01, 95% CI 1.01, 1.02), ischaemic stroke (RR=1.03, 95% CI 1.02, 1.04), but not haemorrhagic stroke (RR=1.00, 95% CI 0.99, 1.01) mortality, were significantly associated with every 10% increase in influenza activity. An increase in circulating A(H1N1)09pdm, A(H3N2) and B type virus were all significantly associated with CVD and ischaemic stroke mortality, but only A(H3N2) and B type virus with IHD mortality. The strongest increase in disease mortality was in the same week as the increase in influenza activity. Annual excess CVD mortality rate attributable to influenza ranged from 54 to 96 per 100 000 population. The 3%-6% CVD mortality attributable to influenza activity was related to an annual excess of 916-1640 CVD deaths in Beijing, China.

CONCLUSIONS

Influenza activity has moderate to strong associations with CVD, IHD and ischaemic stroke mortality in older adults in China. Promoting influenza vaccination could have major health benefit in this population.

BACKGROUND

Influenza may trigger serious CVD events. An estimation of excess CVD mortality attributable to influenza has particular relevance in China where vaccination is low and CVD burden is high.

METHODS

This study analysed data at the population level (age ≥65 years) using linked aggregated data from administrative systems on CVD mortality, influenza surveillance and meteorological data during 2011 to 2018. Quasi-Poisson regression models were used to estimate the excess overall CVD, and separately for IHD, ischaemic stroke, haemorrhagic stroke mortality attributable to influenza, adjusting for influenza activity, time trend, seasonality and ambient temperature. Analyses were also undertaken for influenza subtypes (A(H1N1)09pdm, A(H3N2) and B viruses), and mortality risk with time lags of 1-5 weeks following influenza activity in the current week.

Influenza Vaccination and Outcome in Heart Failure

Influenza virus infection is associated with significant morbidity and mortality in patients with chronic diseases including heart failure (HF). Annual influenza vaccination is recommended to prevent infection during the winter months. Data regarding its clinical benefit in HF patients are sparse. The purpose of the study was to evaluate the effect of influenza vaccination on clinical outcome in patients with HF. Consecutive patients with HF at a health maintenance organization were evaluated for influenza vaccination status during the winter season of 2017/2018 and its association with cardiac-related hospitalizations and death during 1-year after vaccination. The study cohort included 6,435 HF patients. A total of 4,440 patient were vaccinated during the winter season (69% of the HF cohort). The vast majority (96%) were vaccinated before the winter months (September to November). Patients vaccinated were older patients with more co-morbidities. Cox regression analysis after adjustment for clinically significant predictors demonstrated that vaccination was associated with reduced mortality (hazard ratio [HR] 0.77, 95% confidence interval [CI] 0.65 to 0.91, p <0.01) as well as reduced death and cardiovascular hospitalizations (HR 0.83 95% CI 0.76 to 0.90, p <0.001). Adjustment for drug therapy demonstrated a similar result with improved outcome with influenza vaccine. Propensity score matched control analysis demonstrated that vaccination was associated with improved survival (HR 0.80, 95% CI 0.67 to 0.95, p <0.01) and reduced death and cardiovascular hospitalizations (HR 0.86, 95% CI 0.79 to 0.94, p <0.001). In conclusion, Influenza vaccination in patients with HF was associated with improved clinical outcome including improved survival and reduced death and hospitalizations.

Care Optimization Through Patient and Hospital Engagement Clinical Trial for Heart Failure: Rationale and design of CONNECT-HF

Many therapies have been shown to improve outcomes for patients with heart failure (HF) in controlled settings, but there are limited data available to inform best practices for hospital and post-discharge quality improvement initiatives. The CONNECT-HF study is a prospective, cluster-randomized trial of 161 hospitals in the United States with a 2×2 factorial design. The study is designed to assess the effect of a hospital and post-discharge quality improvement intervention compared with usual care (primary objective) on HF outcomes and quality-of-care, as well as to evaluate the effect of hospitals implementing a patient-level digital intervention compared with usual care (secondary objective). The hospital and post-discharge intervention includes audit and feedback on HF clinical process measures and outcomes for patients with HF with reduced ejection fraction (HFrEF) paired with education to sites and clinicians by a trained, nationally representative group of HF and quality improvement experts. The patient-level digital intervention is an optional ancillary study and includes a mobile application and behavioral tools that are intended to facilitate improved use of guideline-directed recommendations for self-monitoring and self-management of activity and medications for HFrEF. The effects of the interventions will be measured through an opportunity-based composite score on quality and time-to-first HF readmission or death among patients with HFrEF who present to study hospitals with acute HF and who consent to participate. The CONNECT-HF study is evaluating approaches for implementing HF guideline recommendations into practice and is one of the largest HF implementation science trials performed to date.

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.