Myocardial dysfunction during H1N1 influenza infection

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.

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.

Comparison of Fragments in Human Hemostatic Proteins That Mimics Fragments in Proteins of A/H1N1 Viruses and Coronaviruses

Objective: To compare the repertoire of proteins of the human hemostatic system and fragments mimicking these proteins in the proteins of influenza A/H1N1 viruses and coronaviruses. Material and methods. Influenza viruses A/H1N1 (A/Brevig Mission/1/18), A/St. Petersburg /RII04/2016 (H1N1)pdm09, coronaviruses SARS-CoV and SARS-CoV-2 (strain Wuhan-Hu-1) were used for comparative computer analysis. The sources of the primary structures of proteins of the analyzed viruses and 41 proteins of the human hemostatic system were publicly available Internet databases, respectively, www.ncbi.nlm.nih.gov and www.nextprot.org. The search for homologous sequences in the structure of viral proteins and hemostatic proteins was carried out by comparing fragments of 12 amino acids in length, taking as related those that showed identity at ≥8 positions. Results. Comparative analysis of the repertoire of cellular proteins of the hemostatic system and fragments mimicking these proteins in the structure of proteins of viruses A/H1N1 1918, A(H1N1)pdm09 isolated in 2016, SARS-CoV and SARS-CoV-2, showed a significant difference between SARS-CoV-2 and analyzed viruses. In the protein structure of the SARS-CoV-2 virus, mimicry was revealed for almost all analyzed hemostasis proteins. As for the comparison of viruses A/H1N1 1918, A(H1N1)pdm09 2016 and SARS-CoV, the influenza virus A/H1N1 1918 and SARS-CoV are the closest in the repertoire of hemostatic proteins. Conclusion. Obtained bioinformatic analysis data can serve as a basis for further study of the role of homologous fragments in the regulation of hemostasis of the host organism.

Prevalence and prognostic implications of myocardial injury in patients with influenza

Aims

Influenza may cause myocardial injury and trigger acute cardiovascular events. The aim of this study was to investigate the prevalence and prognostic implications of elevated high-sensitivity cardiac troponin I (hs-cTnI) in patients with influenza.

Methods and results

In this prospective cohort study, we consecutively enrolled patients with influenza-like illness from two emergency departments in Sweden during three seasons of influenza, 2017–20. Ongoing Influenza infection was diagnosed by polymerase chain reaction and blood samples were collected for later analysis of hs-cTnI. All patients were followed-up for a composite endpoint of major adverse cardiovascular events (MACE) including death, myocardial infarction, unstable angina, heart failure, atrial fibrillation, and stroke within 1 year. Of the 466 patients with influenza-like symptoms, 181 (39%) were positive for influenza. Fifty (28%) patients were hospitalized. High-sensitivity cTnI was elevated in 11 (6%) patients and 8 (4%) experienced MACE. In univariate analyses, MACE was associated with age [hazard ratio (HR): 1.14, 95% confidence interval (CI): 1.05–1.23], hypertension (HR 5.56, 95%CI: 1.12–27.53), estimated glomerular filtration rate (HR: 0.94, 95%CI: 0.91–0.97), and elevated hs-cTnI (HR: 18.29, 95%CI: 4.57–73.24), N-terminal prohormone of brain natriuretic peptide (HR: 14.21, 95%CI: 1.75–115.5), hs-CRP (HR: 1.01, 95%CI: 1.00–1.02), and white blood cell count (HR: 1.12, 95%CI: 1.01–1.25). In multivariate analysis, elevated hs-cTnI was independently associated with MACE (HR: 4.96, 95%CI: 1.10–22.41).

Conclusion

The prevalence of elevated hs-cTnI is low in unselected patients with influenza. Elevated hs-cTnI was associated with poor prognosis. A limitation is that the estimated associations are uncertain due to few events.

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

Purpose of Review

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

Recent Findings

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

Summary

The recent IAMI trial showed that influenza vaccination in patients with recent MI is safe and efficacious at reducing CV morbidity and mortality. Our updated meta-analysis confirms a 25% reduction in MACE. The influenza vaccine should be strongly encouraged in all patients with CVD and incorporated as an essential facet of post-MI care and secondary CVD prevention.

Association of Right Ventricular Dilation and Dysfunction on Echocardiogram with In-Hospital Mortality Among Patients Hospitalized with COVID-19 Compared with Other Acute Respiratory Illness

BACKGROUND

Although right ventricular (RV) dysfunction is associated with mortality in acute COVID-19, the role of RV dilation is uncertain. The prognostic significance of RV dilation and dysfunction among hospitalized patients with acute COVID-19 compared to other respiratory illnesses.

METHODS

We conducted a retrospective cohort study to examine 225 consecutive adults admitted for acute COVID-19 and 6,150 control adults admitted for influenza, pneumonia or ARDS who had a clinical echocardiogram performed. We used logistic regression models to assess associations between RV parameters and in-hospital mortality adjusted for confounders.

RESULTS

Among those with COVID-19, 48/225 (21.3%) died during the index hospitalization compared to 727/6150 (11.8%) with other respiratory illness (p=0.001). Independent of COVID-19, mild and moderate to severe RV dilation were associated with 1.4 and 2.0 times higher risk of inpatient mortality, respectively (95%CI 1.17 to 1.69; p=0.0003; 95%CI 1.62 to 2.47; p<0.0001, respectively). Similarly, mild and moderate RV dysfunction were associated with 1.4 and 1.7 times higher risk of inpatient mortality (95%CI 1.10 to 1.77; p=0.007; 95%CI 1.17 to 2.42; p=0.005, respectively). Relative to normal RV size and non-COVID-19 acute respiratory illness, mild and moderate RV dilation were associated with 1.4 times and 2.0 times higher risk among those without COVID-19 and 1.9 times higher and 3.0 times higher risk among those with COVID-19, with similar findings for RV dysfunction. Having both RV dilation and dysfunction or RV dilation alone were associated with 1.7 times higher risk while RV dysfunction alone was associated with 1.4 times higher risk compared to normal RV size and function.

CONCLUSIONS

RV dilation and dysfunction are associated with increased risk of inpatient mortality among those with COVID-19 and other respiratory illnesses. Abnormal RV findings may identify those at higher risk of short-term mortality from acute respiratory illness including COVID-19 beyond other risk markers.

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.

Clinical Characteristics and Outcomes of Adults With a History of Heart Failure Hospitalized for COVID-19

BACKGROUND

It is important to understand the risk for in-hospital mortality of adults hospitalized with acute coronavirus disease 2019 (COVID-19) infection with a history of heart failure (HF).

METHODS

We examined patients hospitalized with COVID-19 infection from January 1, 2020 to July 22, 2020, from 88 centers across the US participating in the American Heart Association's COVID-19 Cardiovascular Disease registry. The primary exposure was history of HF and the primary outcome was in-hospital mortality. To examine the association between history of HF and in-hospital mortality, we conducted multivariable modified Poisson regression models that included sociodemographics and comorbid conditions. We also examined HF subtypes based on left ventricular ejection fraction in the prior year, when available.

RESULTS

Among 8920 patients hospitalized with COVID-19, mean age was 61.4±17.5 years and 55.5% were men. History of HF was present in 979 (11%) patients. In-hospital mortality occurred in 31.6% of patients with history of HF, and 16.9% in patients without a history of HF. In a fully adjusted model, history of HF was associated with increased risk for in-hospital mortality (relative risk: 1.16 [95% CI, 1.03-1.30]). Among 335 patients with left ventricular ejection fraction, heart failure with reduced ejection fraction was significantly associated with in-hospital mortality in a fully adjusted model (heart failure with reduced ejection fraction relative risk: 1.40 [95% CI, 1.10-1.79]; heart failure with mid-range ejection fraction relative risk: 1.06 [95% CI, 0.65-1.73]; heart failure with preserved ejection fraction relative risk, 1.06 [95% CI, 0.84-1.33]).

CONCLUSIONS

Risk for in-hospital mortality was substantial among adults with history of HF, in large part due to age and comorbid conditions. History of heart failure with reduced ejection fraction may confer especially elevated risk. This population thus merits prioritization for the COVID-19 vaccine.

[Modulation of endothelial factors activity in human endothelial cells in influenza A(H1N1)pdm09 virus infection]

INTRODUCTION

Influenza A virus infection can lead to endothelial dysfunction (ED), including apoptosis of endothelial cells and modulation of endothelial factor activities. Affected biochemical factors may include those playing important roles in vascular homeostasis. However, the effect of this pathogen on the expression pattern of key endothelial factors is still unknown.The aim of this work was to study the expression of endothelial nitric oxide synthase (eNOS) and plasminogen activator inhibitor-1 (PAI-1, serpin E1) in the EA.hy926 endothelial cells.

RESEARCH OBJECTIVES

to assess expression of eNOS and PAI-1 in endothelial cells infected with influenza virus A(H1N1)pdm09, and to identify homologous fragments in structure of viral proteins and endothelial factors.

MATERIAL AND METHODS

Cells were infected with influenza virus A/St. Petersburg/48/16 (H1N1)pdm09 and analyzed in dynamics in 6, 12, 18, 24, 48, and 72 hrs post infection (hpi). Detection of endothelial factors expression levels was performed by immunocytochemical method (ICC) using antibodies for eNOS and PAI-1 while quantitative assessment of expression levels was carried out by program Nis-Elements F3.2 («Nikon», Japan). The search for homologous sequences between viral proteins and eNOS and PAI-1 was performed by computer comparison. Sequences were analyzed as fragments 12 amino acid residues (aar) in length.

RESULTS AND DISCUSSION

eNOS expression in infected cells had decreased to 7.9% by 6 hpi (control was taken as 100%) to 3.3% at 72 hpi. PAI-1 expression varied significantly over the course of the experiment: by 6 hpi it had decreased to 49.6%, and to 43.2% by 12 hpi. Later PAI-1 levels were: 116.3% (18 hpi); 18.9% (24 hpi); 23.5% (48 hpi), and 35% (72 hpi).

CONCLUSION

These results indicate that influenza A infection of endothelial cells causes a significant decrease in eNOS expression, while modulating PAI-1 one. The described phenomenon can be used in the further development of directions of pathogenetic therapy of vascular complications of infection caused by this pathogen.

Acute Cardiac Injury in Coronavirus Disease 2019 and Other Viral Infections-A Systematic Review and Meta-Analysis

OBJECTIVES

Severe acute respiratory syndrome-related coronavirus-2 binds and inhibits angiotensin-converting enzyme-2. The frequency of acute cardiac injury in patients with coronavirus disease 2019 is unknown. The objective was to compare the rates of cardiac injury by angiotensin-converting enzyme-2-binding viruses from viruses that do not bind to angiotensin-converting enzyme-2.

DATA SOURCES

We performed a systematic review of coronavirus disease 2019 literature on PubMed and EMBASE.

STUDY SELECTION

We included studies with ten or more hospitalized adults with confirmed coronavirus disease 2019 or other viral pathogens that described the occurrence of acute cardiac injury. This was defined by the original publication authors or by: 1) myocardial ischemia, 2) new cardiac arrhythmia on echocardiogram, or 3) new or worsening heart failure on echocardiogram.

DATA EXTRACTION

We compared the rates of cardiac injury among patients with respiratory infections with viruses that down-regulate angiotensin-converting enzyme-2, including H1N1, H5N1, H7N9, and severe acute respiratory syndrome-related coronavirus-1, to those with respiratory infections from other influenza viruses that do not bind angiotensin-converting enzyme-2, including Influenza H3N2 and influenza B.

DATA SYNTHESIS

Of 57 studies including 34,072 patients, acute cardiac injury occurred in 50% (95% CI, 44-57%) of critically ill patients with coronavirus disease 2019. The overall risk of acute cardiac injury was 21% (95% CI, 18-26%) among hospitalized patients with coronavirus disease 2019. In comparison, 37% (95% CI, 26-49%) of critically ill patients with other respiratory viruses that bind angiotensin-converting enzyme-2 (p = 0.061) and 12% (95% CI, 7-22%) of critically ill patients with other respiratory viruses that do not bind angiotensin-converting enzyme-2 (p < 0.001) experienced a cardiac injury.

CONCLUSIONS

Acute cardiac injury may be associated with whether the virus binds angiotensin-converting enzyme-2. Acute cardiac injury occurs in half of critically ill coronavirus disease 2019 patients, but only 12% of patients infected by viruses that do not bind to angiotensin-converting enzyme-2.

Cardiac troponin elevation in patients with influenza virus infections

The association between acute infections and cardiac injury, including myocarditis and acute myocardial infarction, is now well established. We have performed a systematic literature review for analyzing the results of epidemiological studies that measured cardiac troponins (cTn) in patients with Influenza virus infections. Overall, 14 articles were finally identified and analyzed. Taken together, the results of the scientific literature suggest that cTn elevation is a relatively rare phenomenon in patients with Influenza virus infection, with frequency generally comprised between 0 and 33%, more likely in elderly patients with significant comorbidities. In patients with modest cTn elevations, this phenomenon is apparently self-limited, transient and reversible, and especially involves patients with Influenza A (especially H1N1). In the minority of patients exhibiting an abrupt appearance of cardiovascular symptoms and concomitant elevation of cTn values, the relative increase of this biomarker reflects the presence of an underlying cardiac injury, that can be either myocarditis or an acute ischemic episode. Enhanced cTn values can also be more frequently observed in Influenza patients with complicated disease, in those developing acute respiratory distress syndrome and cardiac dysfunction, as well as in those at higher risk of death. cTn measurement shall be considered a valuable option in all patients developing acute cardiovascular symptoms during Influenza virus infections, as well as in those bearing cardiac or extra-cardiac comorbidities who bear a higher risk of complications.

Worsening of heart failure by coronavirus disease 2019 is associated with high mortality

AIMS

Patients with advanced heart failure (HF) with reduced left ventricular ejection fraction (HFrEF) and concurrent coronavirus disease 2019 (COVID-19) might have a higher risk of severe events.

METHODS AND RESULTS

We retrospectively studied 16 patients with advanced HFrEF who developed COVID-19 between 1 March and 29 May 2020. Follow-up lasted until 30 September. Ten patients previously hospitalized with decompensated HFrEF were infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during hospitalization. Six patients undergoing ambulatory care at initiation of COVID-19 symptoms were hospitalized because of advanced HFrEF. All patients who experienced worsening of HFrEF due to COVID-19 required higher doses or introduction of additional inotropic drugs or intra-aortic balloon pump in the intensive care unit. The mean intravenous dobutamine dose before SARS-CoV-2 infection in previously hospitalized patients (n = 10) and the median (inter-quartile range) peak intravenous dobutamine dose during SARS-CoV-2 infection in all patients (n = 16) were 2 (0-7) μg/kg/min and 20 (14-20) (P < 0.001), respectively. During follow-up, 56% underwent heart transplantation (n = 2) or died (n = 7). Four patients died during hospitalization from mixed shock consequent to severe acute respiratory syndrome with inflammatory storm syndrome associated with septic and cardiogenic shock during COVID-19. After COVID-19 recovery, two patients died from mixed septic and cardiogenic shock and one from sustained ventricular tachycardia and cardiogenic shock. Five patients were discharged from hospital to ambulatory care. Four were awaiting heart transplantation.

CONCLUSION

Worsening of advanced HF by COVID-19 is associated with high mortality. This report highlights the importance of preventing COVID-19 in patients with advanced HF.

Decongestant use and the risk of myocardial infarction and stroke: a case-crossover study

Pharmacovigilance reports of cerebral and cardiovascular events in those who use decongestants have triggered alerts related to their use. We aimed to assess the risk of stroke and myocardial infarction (MI) associated with the use of decongestants. We conducted a nested case-crossover study of patients with incident stroke and MI identified in France between 2013 and 2016 in two systematic disease registries. Decongestant use in the three weeks preceding the event was assessed using a structured telephone interview. Conditional logistic multivariable models were used to estimate the odds of incident MI and stroke, also accounting for transient risk factors and comparing week 1 (index at-risk time window, immediately preceding the event) to week 3 (reference). Time-invariant risk factors were controlled by design. In total, 1394 patients with MI and 1403 patients with stroke, mainly 70 years old or younger, were interviewed, including 3.2% who used decongestants during the three weeks prior to the event (1.0% definite exposure in the index at-risk time window, 1.1% in the referent time window; adjusted odds ratio (aOR), 0.78; 95%CI, 0.43-1.42). Secondary analysis yielded similar results for individual events (MI/stroke). We observed no increased risk of MI or stroke for patients 70 years of age and younger without previous MI or stroke who used decongestants.

Echocardiographic Features of Cardiac Injury Related to COVID-19 and Their Prognostic Value: A Systematic Review

BACKGROUND

The available information on the echocardiographic features of cardiac injury related to the novel coronavirus disease 2019 (COVID-19) and their prognostic value are scattered in the different literature. Therefore, the aim of this study was to investigate the echocardiographic features of cardiac injury related to COVID-19 and their prognostic value.

METHODS

Published studies were identified through searching PubMed, Embase (Elsevier), and Google scholar databases. The search was performed using the different combinations of the keywords "echocard*," "cardiac ultrasound," "TTE," "TEE," "transtho*," or "transeso*" with "COVID-19," "sars-COV-2," "novel corona, or "2019-nCOV." Two researchers independently screened the titles and abstracts and full texts of articles to identify studies that evaluated the echocardiographic features of cardiac injury related to COVID-19 and/or their prognostic values.

RESULTS

Of 783 articles retrieved from the initial search, 11 (8 cohort and 3 cross-sectional studies) met our eligibility criteria. Rates of echocardiographic abnormalities in COVID-19 patients varied across different studies as follow: RV dilatation from 15.0% to 48.9%; RV dysfunction from 3.6% to 40%; and LV dysfunction 5.4% to 40.0%. Overall, the RV abnormalities were more common than LV abnormalities. The majority of the studies showed that there was a significant association between RV abnormalities and the severe forms and death of COVID-19.

CONCLUSION

The available evidence suggests that RV dilatation and dysfunction may be the most prominent echocardiographic abnormality in symptomatic patients with COVID-19, especially in those with more severe or deteriorating forms of the disease. Also, RV dysfunction should be considered as a poor prognostic factor in COVID-19 patients.

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.

Immune Mechanisms in Cardiovascular Diseases Associated With Viral Infection

Influenza virus infection causes 3-5 million cases of severe illness and 250,000-500,000 deaths worldwide annually. Although pneumonia is the most common complication associated with influenza, there are several reports demonstrating increased risk for cardiovascular diseases. Several clinical case reports, as well as both prospective and retrospective studies, have shown that influenza can trigger cardiovascular events including myocardial infarction (MI), myocarditis, ventricular arrhythmia, and heart failure. A recent study has demonstrated that influenza-infected patients are at highest risk of having MI during the first seven days of diagnosis. Influenza virus infection induces a variety of pro-inflammatory cytokines and chemokines and recruitment of immune cells as part of the host immune response. Understanding the cellular and molecular mechanisms involved in influenza-associated cardiovascular diseases will help to improve treatment plans. This review discusses the direct and indirect effects of influenza virus infection on triggering cardiovascular events. Further, we discussed the similarities and differences in epidemiological and pathogenic mechanisms involved in cardiovascular events associated with coronavirus disease 2019 (COVID-19) compared to influenza infection.

Influenza Vaccination to Reduce Cardiovascular Morbidity and Mortality in Patients With COVID-19: JACC State-of-the-Art Review

Viral respiratory infections are risk factors for cardiovascular disease (CVD). Underlying CVD is also associated with an increased risk of complications following viral respiratory infections, including increased morbidity, mortality, and health care utilization. Globally, these phenomena are observed with seasonal influenza and with the current coronavirus disease 2019 (COVID-19) pandemic. Persons with CVD represent an important target population for respiratory virus vaccines, with capacity developed within 3 large ongoing influenza vaccine cardiovascular outcomes trials to determine the potential cardioprotective effects of influenza vaccines. In the context of COVID-19, these international trial networks may be uniquely positioned to redeploy infrastructure to study therapies for primary and secondary prevention of COVID-19. Here, we describe mechanistic links between influenza and COVID-19 infection and the risk of acute cardiovascular events, summarize the data to date on the potential cardioprotective effects of influenza vaccines, and describe the ongoing influenza vaccine cardiovascular outcomes trials, highlighting important lessons learned that are applicable to COVID-19.

Risk of Severe Influenza Among Adults With Chronic Medical Conditions

BACKGROUND

Severe influenza illness is presumed more common in adults with chronic medical conditions (CMCs), but evidence is sparse and often combined into broad CMC categories.

METHODS

Residents (aged 18-80 years) of Central and South Auckland hospitalized for World Health Organization-defined severe acute respiratory illness (SARI) (2012-2015) underwent influenza virus polymerase chain reaction testing. The CMC statuses for Auckland residents were modeled using hospitalization International Classification of Diseases, Tenth Revision codes, pharmaceutical claims, and laboratory results. Population-level influenza rates in adults with congestive heart failure (CHF), coronary artery disease (CAD), cerebrovascular accidents (CVA), chronic obstructive pulmonary disease (COPD), asthma, diabetes mellitus (DM), and end-stage renal disease (ESRD) were calculated by Poisson regression stratified by age and adjusted for ethnicity.

RESULTS

Among 891 276 adults, 2435 influenza-associated SARI hospitalizations occurred. Rates were significantly higher in those with CMCs compared with those without the respective CMC, except for older adults with DM or those aged <65 years with CVA. The largest effects occurred with CHF (incidence rate ratio [IRR] range, 4.84-13.4 across age strata), ESRD (IRR range, 3.30-9.02), CAD (IRR range, 2.77-10.7), and COPD (IRR range, 5.89-8.78) and tapered with age.

CONCLUSIONS

Our findings support the increased risk of severe, laboratory-confirmed influenza disease among adults with specific CMCs compared with those without these conditions.

Impact of congenital heart disease on outcomes among pediatric patients hospitalized for influenza infection

Background

Young children and those with chronic medical conditions are at risk for complications of influenza including cardiopulmonary compromise. Here we aim to examine risks of mortality, clinical complications in children with congenital heart disease (CHD) hospitalized for influenza.

Methods

We analyzed data from in-hospital pediatric patients from 2003, 2006, 2009, 2012 and 2016 using the nationally representative Kids Inpatient Database (KID). We included children 1 year and older and used weighted data to compare the incidence of in-hospital mortality and rates of complications such as respiratory failure, acute kidney injury, need for mechanical ventilation, arrhythmias and myocarditis.

Results

Data from the KID estimated 125,470 children who were admitted with a diagnosis of influenza infection. Out of those, 2174(1.73%) patients had discharge diagnosis of CHD. Children with CHD who required hospitalization for influenza had higher in-hospital mortality (2.0% vs 0.5%), with an adjusted OR (aOR) of 2.8 (95% CI: 1.7–4.5). Additionally, acute respiratory failure and acute kidney failure were more likely among patients with CHD, with aOR of 1.8 (95% CI: 1.5–2.2) and aOR of 2.2 (95% CI: 1.5–3.1), respectively. Similarly, the rate of mechanical ventilatory support was higher in patients with CHD compared to those without, 14.1% vs 5.6%, aOR of 1.9 (95% CI: 1.6–2.3). Median length of hospital stay in children with CHD was longer than those without CHD [4 (IQR: 2–8) days vs. 2 (IQR: 2–4) days]. Outcomes were similar between those with severe vs non-severe CHD.

Conclusions

Children with CHD who require hospital admission for influenza are at significantly increased risk for in-hospital mortality, morbidities, emphasizing the need to reinforce preventative measures (e.g. vaccination, personal hygiene) in this particularly vulnerable population.

Role of Aging and the Immune Response to Respiratory Viral Infections: Potential Implications for COVID-19

Aging impairs immunity to promote diseases, especially respiratory viral infections. The current COVID-19 pandemic, resulting from SARS-CoV-2, induces acute pneumonia, a phenotype that is alarmingly increased with aging. In this article, we review findings of how aging alters immunity to respiratory viral infections to identify age-impacted pathways common to several viral pathogens, permitting us to speculate about potential mechanisms of age-enhanced mortality to COVID-19. Aging generally leads to exaggerated innate immunity, particularly in the form of elevated neutrophil accumulation across murine and large animal studies of influenza infection. COVID-19 patients who succumb exhibit a 2-fold increase in neutrophilia, suggesting that exaggerated innate immunity contributes to age-enhanced mortality to SARS-CoV-2 infection. Further investigation in relevant experimental models will elucidate the mechanisms by which aging impacts respiratory viral infections, including SARS-CoV-2. Such investigation could identify therapies to reduce the suffering of the population at large, but especially among older people, infected with respiratory viruses.

Obesity, Cardiovascular Disease, and Influenza: How Are They Connected?

Purpose of Review

To better understand the impact of obesity and cardiovascular diseases on influenza A infection.

Recent Findings

This infection could have detrimental outcomes in obese patients with cardiovascular diseases, such as an increased risk, length of hospitalization, disease severity, morbidity, and mortality. Nevertheless, there also might be some cardioprotective benefits associated with influenza vaccination, such as a reduced mortality, hospitalization, and acute coronary syndromes, in patients with coronary heart disease and/or heart failure.

Summary

Obesity negatively impacts immune function and host defense. Recent studies report obesity to be an independent risk factor for increased morbidity and mortality following infection. Obese patients might need special considerations in the treatment; however, there is not enough evidence to fully comprehend the mechanisms behind the reduced immunocompetence when influenza A infection occurs. Future studies should focus on special consideration treatments when the patients have not been vaccinated and have cardiovascular diseases.

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.

Right Ventricular Hypertrophy in Refractory Acute Respiratory Distress Syndrome Treated With Venovenous Extracorporeal Membrane Oxygenation Support

OBJECTIVE

In severe acute respiratory distress syndrome (ARDS) treated with extracorporeal membrane oxygenation (ECMO), right ventricular (RV failure) and dilation have been investigated with the use of echocardiography, whereas RV hypertrophy has not been addressed in the literature. The present study assessed the incidence of RV hypertrophy using echocardiography before ECMO treatment and at intensive care unit (ICU) discharge in severe ARDS patients.

DESIGN

Observational, retrospective, single-center study.

SETTING

A single ECMO center.

PARTICIPANTS

The study comprised 46 consecutive patients with severe ARDS.

INTERVENTION

Echocardiographic evaluation and ECMO support.

MEASUREMENTS AND MAIN RESULTS

A dual-lumen cannula was implanted in most patients (38/46 [82.6%]). Before the start of ECMO, RV hypertrophy was present in 28 patients (60.8%) with no significant differences in baseline characteristics between the 2 subgroups. The ICU mortality rate was 30.4% (14/46), with no difference between patients with RV hypertrophy and those without. At ICU discharge, all patients showed RV hypertrophy.

CONCLUSIONS

In severe ARDS treated with ECMO support, RV hypertrophy is a common finding and patients with normal RV wall thickness developed RV hypertrophy after ECMO support. The latter finding may suggest that during ECMO support, the right ventricle still may be subjected to increased afterload. However, additional research should be performed to elucidate the spectrum of mechanism(s) involved in the genesis of RV hypertrophy.

Extreme influenza epidemics and out-of-hospital cardiac arrest

INTRODUCTION

There is compelling evidence for an association between influenza epidemics and major adverse cardiovascular events. However, the role of extreme influenza epidemics as a trigger of out-of-hospital cardiac arrest (OHCA) is unclear. Thus, we evaluated the potential association between extreme influenza epidemics and incidence of OHCA.

METHODS

We used a quasi-experimental design with time-series analysis of national registry data for cases of OHCA from all 47 prefectures of Japan during influenza seasons between 2005 and 2014. A Poisson regression time-series model with a distributed lag non-linear model was used to estimate prefecture-specific effects of influenza epidemics on OHCA. A multivariate meta-analysis was conducted for nationally pooled estimates.

RESULTS

In total, 481,516 OHCAs of presumed cardiac origin were reported during the study period. The minimum morbidity percentile (MMP) was estimated as the 0th percentile for influenza incidence. The overall cumulative relative risk versus the MMP was 1.25 (95% confidence interval, 1.16-1.34) for extreme influenza epidemics (at the 99th percentile of influenza incidence). The effect of extreme influenza epidemics was significant for lag periods of 1.5-7.1 and 17.9-21 days. Multivariate random-effects meta-analysis indicated significant spatial heterogeneity among prefectures (Cochran Q test, p = 0.011; I² = 23.2%).

CONCLUSION

Extreme influenza epidemics are associated with higher risk of OHCA. Our findings suggest that several weeks' prevention for extreme influenza infections should be implemented to reduce the risk of OHCA.

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

OBJECTIVES

This study sought to evaluate and contribute to the limited data on U.S. hospital practice patterns with respect to respiratory vaccination in patients hospitalized with heart failure (HF).

BACKGROUND

Respiratory infection is a major driver of morbidity in patients with HF, and many influenza and pneumococcal infections may be prevented by vaccination.

METHODS

This study evaluated patients hospitalized at centers participating in the Get With The Guidelines-HF (GWTG-HF) registry from October 2012 to March 2017. The proportion of patients receiving vaccination was described for influenza and pneumococcal vaccination, respectively. The association of hospital-level vaccination rates with individual GWTG-HF performance measures and defect-free care was evaluated using multivariable modeling.

RESULTS

This study evaluated 313,761 patients discharged from 392 hospitals during the study period. The proportion of patients receiving influenza vaccination was 68% overall and declined from 70% in 2012 to 2013 to 66% in 2016 to 2017 (p < 0.001), although this was not statistically significant after adjustment (odds ratio: 1.05 per flu season; 95% confidence interval [CI]: 0.94 to 1.18). The proportion of patients receiving pneumococcal vaccination was 66% overall and decreased over the study period from 71% in 2013 to 60% in 2016 (p < 0.001), remaining significant after adjustment (odds ratio: 0.75 per calendar year; 95% CI: 0.67 to 0.84). Hospitals with higher vaccination rates were more likely to discharge patients with higher performance on defect-free care and individual GWTG-HF performance measures (p < 0.001). In a subset of patients with linked Medicare claims, vaccinated patients had similar rates of 1-year all-cause mortality (adjusted hazard ratio: 0.96 [95% CI: 0.89 to 1.03] for influenza vaccination; adjusted hazard ratio: 0.95 [95% CI: 0.89 to 1.01] for pneumococcal vaccination) compared with those not vaccinated.

CONCLUSIONS

Nearly 1 in 3 patients hospitalized with HF at participating hospitals were not vaccinated for influenza or pneumococcal pneumonia, and vaccination rates did not improve from 2012 to 2017. Hospitals that exhibited higher vaccination rates performed well with respect to other HF quality of care measures. Vaccination status was not associated with differences in clinical outcomes. Further randomized controlled data are needed to assess the relationship between vaccination and outcomes.

High-dose influenza vaccine to reduce clinical outcomes in high-risk cardiovascular patients: Rationale and design of the INVESTED trial

BACKGROUND

Influenza leads to significant cardiopulmonary morbidity and mortality-particularly in patients with cardiovascular disease-that may be prevented with a standard influenza vaccine. However, patients with cardiovascular conditions have a reduced immune response to influenza vaccine, potentially resulting in reduced effectiveness for preventing clinical events. High-dose vaccine augments immune response in cardiac patients, suggesting that a high-dose influenza vaccination strategy may further reduce morbidity and mortality. Alternatively, broader coverage with an influenza vaccine containing an increased number of viral strains is an alternative strategy without direct evaluation.

RESEARCH DESIGN AND METHODS

INfluenza Vaccine to Effectively Stop Cardio Thoracic Events and Decompensated heart failure (INVESTED) is a pragmatic, randomized, double-blind, parallel-group, active-controlled trial comparing the effectiveness of an annual vaccination strategy of high-dose trivalent versus standard-dose quadrivalent influenza vaccine in patients with a history of recent heart failure or myocardial infarction hospitalization. The trial will enroll approximately 9,300 patients over 4 influenza seasons. The primary hypothesis is that high-dose influenza vaccine will reduce the composite outcome of all-cause mortality and hospitalization from a cardiovascular or pulmonary cause compared with standard-dose influenza vaccine within each enrolling season. Approximately 1,300 primary outcome events will provide >90% power to detect an 18% relative risk reduction at a 2-sided α level of .05.

CONCLUSION

INVESTED is the largest and longest study to assess whether high-dose influenza vaccine is superior to standard-dose influenza vaccine in reducing cardiopulmonary events in a high-risk cardiovascular population (ClinicalTrials.gov Identifier: NCT02787044).

Seasonal Influenza Infections and Cardiovascular Disease Mortality

IMPORTANCE

Cardiovascular deaths and influenza epidemics peak during winter in temperate regions.

OBJECTIVES

To quantify the temporal association between population increases in seasonal influenza infections and mortality due to cardiovascular causes and to test if influenza incidence indicators are predictive of cardiovascular mortality during the influenza season.

DESIGN, SETTING, AND PARTICIPANTS

Time-series analysis of vital statistics records and emergency department visits in New York City, among cardiovascular deaths that occurred during influenza seasons between January 1, 2006, and December 31, 2012. The 2009 novel influenza A(H1N1) pandemic period was excluded from temporal analyses.

EXPOSURES

Emergency department visits for influenza-like illness, grouped by age (≥0 years and ≥65 years) and scaled by laboratory surveillance data for viral types and subtypes, in the previous 28 days.

MAIN OUTCOMES AND MEASURES

Mortality due to cardiovascular disease, ischemic heart disease, and myocardial infarction.

RESULTS

Among adults 65 years and older, who accounted for 83.0% (73 363 deaths) of nonpandemic cardiovascular mortality during influenza seasons, seasonal average influenza incidence was correlated year to year with excess cardiovascular mortality (Pearson correlation coefficients ≥0.75, P ≤ .05 for 4 different influenza indicators). In daily time-series analyses using 4 different influenza metrics, interquartile range increases in influenza incidence during the previous 21 days were associated with an increase between 2.3% (95% CI, 0.7%-3.9%) and 6.3% (95% CI, 3.7%-8.9%) for cardiovascular disease mortality and between 2.4% (95% CI, 1.1%-3.6%) and 6.9% (95% CI, 4.0%-9.9%) for ischemic heart disease mortality among adults 65 years and older. The associations were most acute and strongest for myocardial infarction mortality, with each interquartile range increase in influenza incidence during the previous 14 days associated with mortality increases between 5.8% (95% CI, 2.5%-9.1%) and 13.1% (95% CI, 5.3%-20.9%). Out-of-sample prediction of cardiovascular mortality among adults 65 years and older during the 2009-2010 influenza season yielded average estimates with 94.0% accuracy using 4 different influenza metrics.

CONCLUSIONS AND RELEVANCE

Emergency department visits for influenza-like illness were associated with and predictive of cardiovascular disease mortality. Retrospective estimation of influenza-attributable cardiovascular mortality burden combined with accurate and reliable influenza forecasts could predict the timing and burden of seasonal increases in cardiovascular mortality.

The use of echocardiographic indices in defining and assessing right ventricular systolic function in critical care research

PURPOSE

Many echocardiographic indices (or methods) for assessing right ventricular (RV) function are available, but each has its strengths and limitations. In some cases, there might be discordance between the indices. We conducted a systematic review to audit the echocardiographic RV assessments in critical care research to see if a consistent pattern existed. We specifically looked into the kind and number of RV indices used, and how RV dysfunction was defined in each study.

METHODS

Studies conducted in critical care settings and reported echocardiographic RV function indices from 1997 to 2017 were searched systematically from three databases. Non-adult studies, case reports, reviews and secondary studies were excluded. These studies' characteristics and RV indices reported were summarized.

RESULTS

Out of 495 non-duplicated publications found, 81 studies were included in our systematic review. There has been an increasing trend of studying RV function by echocardiography since 2001, and most were conducted in ICU. Thirty-one studies use a single index, mostly TAPSE, to define RV dysfunction; 33 used composite indices and the combinations varied between studies. Seventeen studies did not define RV dysfunction. For those using composite indices, many did not explain their choices.

CONCLUSIONS

TAPSE seemed to be the most popular index in the last 2-3 years. Many studies used combinations of indices but, apart from cor pulmonale, we could not find a consistent pattern of RV assessment and definition of RV dysfunction amongst these studies.

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.

Perioperative Management of the Adult Patient on Venovenous Extracorporeal Membrane Oxygenation Requiring Noncardiac Surgery

The use of venovenous extracorporeal membrane oxygenation is increasing worldwide. These patients often require noncardiac surgery. In the perioperative period, preoperative assessment, patient transport, choice of anesthetic type, drug dosing, patient monitoring, and intraoperative and postoperative management of common patient problems will be impacted. Furthermore, common monitoring techniques will have unique limitations. Importantly, patients on venovenous extracorporeal membrane oxygenation remain subject to hypoxemia, hypercarbia, and acidemia in the perioperative setting despite extracorporeal support. Treatments of these conditions often require both manipulation of extracorporeal membrane oxygenation settings and physiologic interventions. Perioperative management of anticoagulation, as well as thresholds to transfuse blood products, remain highly controversial and must take into account the specific procedure, extracorporeal membrane oxygenation circuit function, and patient comorbidities. We will review the physiologic management of the patient requiring surgery while on venovenous extracorporeal membrane oxygenation.

A novel risk score for severe ARDS patients undergoing ECMO after retrieval from peripheral hospitals

BACKGROUND

Extracorporeal Membrane Oxygenation in severe ARDS unresponsive to conventional protective ventilation is associated with elevated costs, resource and complications, and appropriate risk stratification of candidate patients could be useful to recognize those more likely to benefit from ECMO. We aimed to derive a new outcome prediction score for patients retrieved by our ECMO team from peripheral centers, including systematic echocardiographic evaluation before ECMO start.

METHODS

Sixty-nine consecutive patients with refractory ARDS requiring ECMO transferred from peripheral centers to our ICU (a tertiary ECMO referral center), from 1 October 2009 to 31 December 2015, were assessed.

RESULTS

All patients were transported on ECMO (distance, median 77, range 4-456 km) The mortality rate was 41% (28/69). Our new risk score included age ≥ 42 years, BMI < 31 kg/m² , RV dilatation, and pH < 7.35. The proposed cut off (Youden's index method) of nine had a sensitivity of 96% and a specificity of 30% (AUC-ROC: 0.85, 95% CI: 0.76-0.94, P < 0.001). When assessing the discriminatory ability of our risk score in the population of local patients, survivors had a mean value of 15.4 ± 8.6, whereas non-survivors showed a mean value of 20.1 ± 7.4 (P < 0.001).

CONCLUSIONS

Our new risk score shows good discriminatory ability both in patients retrieved from peripheral centers and in those implanted at our center. This score includes variables easily available at bedside, and, for the first time, a pathophysiologic element, RV dilatation.

Lactate and Echocardiography Before Veno-Venous Extracorporeal Membrane Oxygenation Support

BACKGROUND

Lactate has been recognised as a prognostic factor in several critical conditions. Veno-Venous Extracorporeal Membrane Oxygenation (VV-ECMO) is a well-established therapy in patients with Acute Respiratory Disease Syndrome (ARDS) unresponsive to conventional therapy and echocardiography pre ECMO initiation has been recently reported to help in risk stratifying these patients.

METHODS

We assessed whether the detection of hyperlactataemia could be associated with the presence of left ventricle (LV) or right ventricle (RV) dysfunction in 121 consecutive patients with refractory ARDS.

RESULTS

The mortality rate was 42.9% (52/121). Higher dosages of norepinephrine and dobutamine were administered to non survivors (p=0.023 and p=0.047, respectively) who showed significantly higher levels of lactate (p=0.002). At echocardiography, non survivors showed higher values of systolic pulmonary artery pressure (sPAP) (p=0.05) and a higher incidence of RV dysfunction (as indicated by lower Tricuspid Annular Plane Excursion (TAPSE)) and RV dilatation (p=0.001). At multivariate logistic regression analysis, the following variables were independent predictors of death: body mass index (BMI) (OR: 0.914, 95%CI 0.857-0.975, p=0.006), RV dilatation (OR: 0.239, 95%CI 0.101-0.561, p=0.001) and lactate (OR: 1.292, 95%CI 1.015-1.645, p=0.038). Lactate values were directly correlated with the simplified acute physiology score (SAPS) II (r=0.38, p<0.001), while they showed an indirect correlation with left ventricular ejection fraction (LVEF) (r=-0.24, p=0.009) and TAPSE (r=-0.21, p=0.024).

CONCLUSIONS

In refractory ARDS, hyperlactataemia before VVV-ECMO identified a subset of patients at higher risk of death, being an independent predictor of in-Intensive Care Unit (ICU) mortality. Lactate values are mainly related to disease severity (as indicated by SAPS II) and haemodynamic impairment (as inferred by LVEF) and RV failure, as (indicated by TAPSE).

Influenza H1N1 Infection Leading To Cardiac Tamponade in a Previously Healthy Patient: A Case Report

Introduction

The cardiac manifestations of influenza A are broad, ranging from self-limited pericarditis to fatal cardiomyopathy. The 2009 H1N1 influenza A (H1N1) strain is a rare cause of pericarditis, and its role in developing a pericardial effusion leading to tamponade has infrequently been reported.

Case Presentation

We describe a case of a young female with no prior cardiovascular history who presents with a pericardial effusion and shock secondary to cardiac tamponade from pericarditis due to H1N1 influenza A.

Conclusions

This case highlights the potential severity of H1N1 infections and the utility of considering cardiac tamponade in patients presenting with influenza symptoms and circulatory collapse.

Pulmonary vascular dysfunction in refractory acute respiratory distress syndrome before veno-venous extracorporeal membrane oxygenation

BACKGROUND

Pulmonary vascular dysfunction has been described in patients with acute respiratory distress syndrome (ARDS). Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a well-established treatment for these patients. We hypothesized that severe pulmonary vascular dysfunction and cor pulmonale identified by echocardiography before cannulation in these patients were associated with worse survival.

METHODS

Echocardiography was used to identify pulmonary hypertension in 21 patients with refractory ARDS just before ECMO implantation. Survival was compared for those with and without cor pulmonale.

RESULTS

In our series, the overall mortality rate was 57.1% (12/21). Echocardiographic exams were transthoracic in 5 patients (23.8%), transesophageal in 4 patients (19%), and both (transthoracic and transesophageal) in the remaining 12 patients (57.1%). In our series, six patients (28.5%) showed LV dysfunction. Acute cor pulmonale was detectable in 2 patients (9.5%), while the remaining 19 patients showed moderate pulmonary dysfunction. Survivors had a higher pre-cannulation LV ejection fraction (EF) (P = 0.02) and tricuspid annular plane excursion (P = 0.04), and lower peak systolic pulmonary artery pressures (P = 0.02).

CONCLUSIONS

In patients with refractory ARDS immediately before ECMO implantation, the prevalence of acute cor pulmonale is low (9.5%). Survival is associated with higher LVEF and lower systolic pulmonary arterial pressure. These findings support the idea that echocardiographic assessment of pulmonary artery pressure in patients with refractory ARDS before VV-ECMO implantation may have value for risk-stratification.

Serial measurements of troponin and echocardiography in patients with moderate-to-severe acute respiratory distress syndrome

PURPOSE

To assess the clinical significance of serial troponin I levels (measured in the first 72 hours from admission) in 42 consecutive patients with moderate-to-severe acute respiratory distress syndrome (ARDS). Echocardiography and electrocardiogram testings were serially performed in the time window.

MATERIALS AND METHODS

Troponin I was measured every 12 hours in the first 72 hours from intensive care unit (ICU) admission. Echocardiography and electrocardiogram testings were serially performed in the same time window to clinically interpret Tn I levels.

RESULTS

Patients with admission positive Tn I (38.1%) showed higher values of systolic pulmonary hypertension (P = .013) associated with significantly lower values of tricuspid annular plane excursion (P = .011). Twenty-five patients (25/42, 59.5%) exhibited positive peak Tn I and at second echocardiographic assessment exhibited significant lower tricuspid annular plane excursion values (P = .005). At stepwise regression analysis the following variables were an independent predictor for in-ICU mortality: Pco2 (OR 1.08, 95% CI 1.011-1.161, P = .023), systolic pulmonary arterial hypertension (OR 0.83, 95% CI 0.701-0.977, P = .002), log peak Tn I (OR 3.56, 95% CI 1.045-12.132, P = .042).

CONCLUSIONS

In moderate-to-severe ARDS, serial troponin I assessment together with echocardiography evaluation helped to identify a subgroup at higher risk for in-ICU death. Moreover, troponin release can be related to right ventricular dysfunction, thus highlighting the clinical role of echocardiography in ARDS patients.

Acute cardiac injury events ≤30 days after laboratory-confirmed influenza virus infection among U.S. veterans, 2010-2012

BACKGROUND

Cardiac injury is a known potential complication of influenza infection. Because U.S. veterans cared for at the U.S. Department of Veterans Affairs are older and have more cardiovascular disease (CVD) risk factors than the general U.S. population, veterans are at risk for cardiac complications of influenza infection. We investigated biomarkers of cardiac injury characteristics and associated cardiac events among veterans who received cardiac biomarker testing ≤30 days after laboratory-confirmed influenza virus infection.

METHODS

Laboratory-confirmed influenza cases among veterans cared for at U.S. Department of Veterans Affairs' facilities for October 2010-December 2012 were identified using electronic medical records (EMRs). Influenza confirmation was based on respiratory specimen viral culture or antigen or nucleic acid detection. Acute cardiac injury (ACI) was defined as an elevated cardiac biomarker (troponin I or creatinine kinase isoenzyme MB) >99 % of the upper reference limit occurring ≤30 days after influenza specimen collection. EMRs were reviewed for demographics, CVD history and risk factors, and ACI-associated cardiac events.

RESULTS

Among 38,197 patients with influenza testing results, 4,469 (12 %) had a positive result; 600 of those patients had cardiac biomarker testing performed ≤30 days after influenza testing, and 143 (24 %) had one or more elevated cardiac biomarkers. Among these 143, median age was 73 years (range 44-98 years), and 98 (69 %) were non-Hispanic white. All patients had one or more CVD risk factors, and 98 (69 %) had a history of CVD. Eighty-six percent of ACI-associated events occurred within 3 days of influenza specimen collection date. Seventy patients (49 %) had documented or probable acute myocardial infarction, 8 (6 %) acute congestive heart failure, 6 (4 %) myocarditis, and 4 (3 %) atrial fibrillation. Eleven (8 %) had non-cardiac explanations for elevated cardiac biomarkers, and 44 (31 %) had no documented explanation. Sixty-eight (48 %) patients had received influenza vaccination during the related influenza season.

CONCLUSION

Among veterans with laboratory-confirmed influenza infection and cardiac biomarker testing ≤30 days after influenza testing, approximately 25 % had evidence of ACI, the majority within 3 days. Approximately half were myocardial infarctions. Our findings emphasize the importance of considering ACI associated with influenza infection among patients at high risk, including this older population with prevalent CVD risk factors.