Acute Infection and Myocardial Infarction

Risk factors for acute myocardial infarction in patients with alcohol-related cirrhosis - a Danish nested case-control study

BACKGROUND & AIMS

Alcohol-related cirrhosis (ALD cirrhosis) has a weaker effect on acute myocardial infarction (MI) than on other arterial or venous thromboses, and the reasons for this pattern are unclear. This study aimed to identify risk factors of MI amongst patients with ALD cirrhosis.

METHODS

This nationwide register-based nested case-control study was conducted within a cohort of all Danish patients diagnosed with ALD cirrhosis from 2000-2019. Patients with first-time MI after diagnosis of ALD cirrhosis were identified as cases, and matching cohort members (10:1) with no history of MI, using risk-set sampling. We selected candidate risk factors a priori and used conditional logistic regression to study the association between them and the adjusted odds ratio of MI.

RESULTS AND CONCLUSIONS

We included 373 cases and 3,730 controls. We identified the following risk factors for MI: hospitalization for infection (adjusted odds ratio 2.26 [95% CI 1.38-3.71]), recent surgery (adjusted odds ratio 1.82 [95% CI 1.18-2.81]), history of atherosclerosis (adjusted odds ratio 1.89 [95% CI 1.39-2.57]), cardiac ischemia (adjusted odds ratio 6.23 [95% CI 4.30-9.04]), heart failure (adjusted odds ratio 2.83 [95% CI 1.90-4.22]) or chronic obstructive pulmonary disease (COPD) (adjusted odds ratio 2.26 [95% CI 1.62-3.17]). Use of anticoagulants had a protective effect (adjusted odds ratio 0.47 [95% CI 0.25-0.91]). Our findings contribute to the understanding of risk factors for MI in patients with ALD cirrhosis. They may have clinical implications e.g. for the decision to offer thromboprophylaxis.

Prognostic Implications of the Timing of ST-Elevation Myocardial Infarction Development in Relation to COVID-19 Infection

Background: Patients with ST-segment elevation myocardial infarction (STEMI) and COVID-19 infection have a worse clinical course and prognosis. The prognostic significance of the timing of STEMI in relation to COVID-19 infection was not investigated. Objectives: To assess whether the time of STEMI development in relation to COVID-19 infection (concurrent or following the infection) influenced the short-term prognosis. Methods: This was an observational study of consecutive COVID-19 patients with STEMI admitted to the COVID-hospital Batajnica (February 2021-March 2022). The patients were divided into the "STEMI first" group: patients with STEMI and a positive polymerase chain reaction test for COVID-19, and the "COVID-19 first" group: patients who developed STEMI during COVID-19 treatment. All patients underwent coronary angiography. The primary endpoint was in-hospital all-cause mortality. Results: The study included 87 patients with STEMI and COVID-19 (Mage, 66.7 years, 66% male). The "STEMI first" group comprised 54 (62.1%) patients, and the "COVID-19 first" group included 33 (37.9%) patients. Both groups shared a comparatively high burden of comorbidities, similar angiographic and procedural characteristics, and high percentages of performed percutaneous coronary interventions with stent implantation (90.7% vs. 87.9%). In-hospital mortality was significantly higher in the "COVID-19 first" group compared to the "STEMI first" group (51.5% vs. 27.8%). Following adjustment, the "COVID-19 first" group had a hazard ratio of 3.22 (95% confidence interval, 1.18-8.75, p = .022) for in-hospital all-cause death, compared with the "STEMI first" group (reference). Conclusion: Clinical presentation with COVID-19 infection, followed by STEMI ("COVID-19 first"), was associated with greater short-term mortality compared to patients presenting with STEMI and testing positive for COVID-19 ("STEMI first").

Risk factors for sternal wound infection after median sternotomy: A nested case-control study and time-to-event analysis

Although potential risk factors for sternal wound infection (SWI) have been extensively studied, the onset time of SWI and different risk factors for superficial and deep SWI were rarely reported. This nested case-control study aims to compare the onset time and contributors between superficial and deep SWI. Consecutive adult patients who underwent cardiac surgery through median sternotomy in a single center from January 2011 to January 2021 constituted the cohort. The case group was those who developed SWI as defined by CDC and controls were matched 6:1 per case. Kaplan-Meier analysis, LASSO and univariate and multivariate Cox regressions were performed. A simple nomogram was established for clinical prediction of the risk of SWI. The incidence of SWI was 1.1% (61 out of 5471) in our cohort. Totally 366 controls were matched to 61 cases. 26.2% (16 of 61) SWI cases were deep SWI. The median onset time of SWI was 35 days. DSWI had a longer latency than SSWI (median time 46 days vs. 32 days, p = 0.032). Kaplan-Meier analyses showed different time-to-SWI between patients with and without DM (p = 0.0011) or MI (p = 0.0019). Multivariate Cox regression showed that BMI (HR = 1.083, 95% CI: 1.012-1.116, p = 0.022), DM (HR = 2.041, 95% CI: 1.094-3.805, p = 0.025) and MI (HR = 2.332, 95% CI: 1.193-4.557, p = 0.013) were independent risk factors for SWI. Superficial SWI was only associated with BMI (HR = 1.089, 95% CI: 1.01-1.175, p = 0.027), while deep SWI was associated with DM (HR = 3.271, 95% CI: 1.036-10.325, p = 0.043) and surgery time (HR = 1.004, 95% CI: 1.001-1.008, p = 0.027). The nomogram for SWI prediction had an AUC of 0.67, good fitness and clinical effectiveness as shown by the calibration curve and decision curve analyses. BMI, DM and MI were independent risk factors for SWI. DSWI had a longer latency and different risk factors compared to SSWI. The nomogram showed a fair performance and good effectiveness for the clinical prediction of SWI.

Diabetes and infection: review of the epidemiology, mechanisms and principles of treatment

An association between diabetes and infection has been recognised for many years, with infection being an important cause of death and morbidity in people with diabetes. The COVID-19 pandemic has re-kindled an interest in the complex relationship between diabetes and infection. Some infections occur almost exclusively in people with diabetes, often with high mortality rates without early diagnosis and treatment. However, more commonly, diabetes is a complicating factor in many infections. A reciprocal relationship occurs whereby certain infections and their treatments may also increase the risk of diabetes. People with diabetes have a 1.5- to 4-fold increased risk of infection. The risks are the most pronounced for kidney infection, osteomyelitis and foot infection, but are also increased for pneumonia, influenza, tuberculosis, skin infection and general sepsis. Outcomes from infection are worse in people with diabetes, with the most notable example being a twofold higher rate of death from COVID-19. Hyperglycaemia has deleterious effects on the immune response. Vascular insufficiency and neuropathy, together with altered skin, mucosal and gut microbial colonisation, contribute to the increased risk of infection. Vaccination is important in people with diabetes although the efficacy of certain immunisations may be compromised, particularly in the presence of hyperglycaemia. The principles of treatment largely follow those of the general population with certain notable exceptions.

Pathogenic mechanisms of cardiovascular damage in COVID-19

BACKGROUND

COVID-19 is a new infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS CoV-2). Since the outbreak in December 2019, it has caused an unprecedented world pandemic, leading to a global human health crisis. Although SARS CoV-2 mainly affects the lungs, causing interstitial pneumonia and severe acute respiratory distress syndrome, a number of patients often have extensive clinical manifestations, such as gastrointestinal symptoms, cardiovascular damage and renal dysfunction.

PURPOSE

This review article discusses the pathogenic mechanisms of cardiovascular damage in COVID-19 patients and provides some useful suggestions for future clinical diagnosis, treatment and prevention.

METHODS

An English-language literature search was conducted in PubMed and Web of Science databases up to 12th April, 2024 for the terms "COVID-19", "SARS CoV-2", "cardiovascular damage", "myocardial injury", "myocarditis", "hypertension", "arrhythmia", "heart failure" and "coronary heart disease", especially update articles in 2023 and 2024. Salient medical literatures regarding the cardiovascular damage of COVID-19 were selected, extracted and synthesized.

RESULTS

The most common cardiovascular damage was myocarditis and pericarditis, hypertension, arrhythmia, myocardial injury and heart failure, coronary heart disease, stress cardiomyopathy, ischemic stroke, blood coagulation abnormalities, and dyslipidemia. Two important pathogenic mechanisms of the cardiovascular damage may be direct viral cytotoxicity as well as indirect hyperimmune responses of the body to SARS CoV-2 infection.

CONCLUSIONS

Cardiovascular damage in COVID-19 patients is common and portends a worse prognosis. Although the underlying pathophysiological mechanisms of cardiovascular damage related to COVID-19 are not completely clear, two important pathogenic mechanisms of cardiovascular damage may be the direct damage of the SARSCoV-2 infection and the indirect hyperimmune responses.

Coronary and Cerebrovascular Events and Exacerbation of Existing Conditions After Laboratory-Confirmed Influenza Infection Among US Veterans: A Self-Controlled Case Series Study

BACKGROUND

Influenza may contribute to coronary/cerebrovascular events and exacerbate underlying conditions.

METHODS

We used self-controlled case series (SCCS) design to analyze data from US Veterans ≥18 years with coronary/cerebrovascular or exacerbation event +/-1 year of lab-confirmed influenza (LCI) during 2010-2018. We estimated the incidence ratio (IR) (95% CI) of the event for risk interval (Days 1-7 post-LCI) versus control interval (all other times +/-1 year of LCI) with fixed-effects conditional Poisson regression. We included biomarker data for mediation analysis.

RESULTS

We identified 3439 episodes with coronary/cerebrovascular-related hospitalizations. IRs (95% CI) for LCI risk versus control interval were STEMI 0.6 (0.1, 4.4), NSTEMI 7.3 (5.8, 9.2), ischemic stroke 4.0 (3.0, 5.4), hemorrhagic stroke 6.2 (3.4, 11.5), and coronary spasm 1.3 (0.5, 3.0). IR significantly increased for NSTEMI and ischemic stroke among those ≥ 65 years. IR for NSTEMI and ischemic stroke dropped 26% and 10%, respectively, when white blood cell (WBC) and platelet count were considered. LCI was significantly associated with exacerbation of preexisting asthma, chronic obstructive pulmonary disease, and congestive heart failure.

CONCLUSIONS

We found significant association between LCI and hospitalization for NSTEMI, ischemic stroke, and hemorrhagic stroke, the latter possibly due to unaccounted time-varying confounding in SCCS design.

Chronic TNF exposure induces glucocorticoid-like immunosuppression in the alveolar macrophages of aged mice that enhances their susceptibility to pneumonia

Chronic low-grade inflammation, particularly elevated tumor necrosis factor (TNF) levels, occurs due to advanced age and is associated with greater susceptibility to infection. One reason for this is age-dependent macrophage dysfunction (ADMD). Herein, we use the adoptive transfer of alveolar macrophages (AM) from aged mice into the airway of young mice to show that inherent age-related defects in AM were sufficient to increase the susceptibility to Streptococcus pneumoniae, a Gram-positive bacterium and the leading cause of community-acquired pneumonia. MAPK phosphorylation arrays using AM lysates from young and aged wild-type (WT) and TNF knockout (KO) mice revealed multilevel TNF-mediated suppression of kinase activity in aged mice. RNAseq analyses of AM validated the suppression of MAPK signaling as a consequence of TNF during aging. Two regulatory phosphatases that suppress MAPK signaling, Dusp1 and Ptprs, were confirmed to be upregulated with age and as a result of TNF exposure both ex vivo and in vitro. Dusp1 is known to be responsible for glucocorticoid-mediated immune suppression, and dexamethasone treatment increased Dusp1 and Ptprs expression in cells and recapitulated the ADMD phenotype. In young mice, treatment with dexamethasone increased the levels of Dusp1 and Ptprs and their susceptibility to infection. TNF-neutralizing antibody reduced Dusp1 and Ptprs levels in AM from aged mice and reduced pneumonia severity following bacterial challenge. We conclude that chronic exposure to TNF increases the expression of the glucocorticoid-associated MAPK signaling suppressors, Dusp1 and Ptprs, which inhibits AM activation and increases susceptibility to bacterial pneumonia in older adults.

Risk of bleeding amongst warfarin and direct oral anticoagulant users prescribed immediate antibiotics for respiratory tract infection: Cohort study

PURPOSE

Incidence of bleeding amongst warfarin and direct oral anticoagulant (DOAC) users is greater following a respiratory tract infection (RTI). It is unclear whether immediate antibiotics modify this association. We estimated the risk of bleeding amongst warfarin and DOAC users with RTI by antibiotic treatment.

METHODS

This retrospective cohort study used data from the Clinical Practice Research Datalink (CPRD) GOLD for adults in England prescribed warfarin or a DOAC, who sought primary care for an RTI between 1st January 2011 and 31st December 2019. Outcomes were major bleeding (hospital admission for intracranial or gastrointestinal bleeding), and non-major bleeding (hospital admission or General Practice consult for epistaxis, haemoptysis, or haematuria). Cox models derived hazard ratios (HRs) and 95% confidence intervals (CIs) for each outcome, adjusting for confounders using inverse probability of treatment weighting.

RESULTS

Of 14 817 warfarin and DOAC users consulting for an RTI, 8768 (59%) were prescribed immediate antibiotics and 6049 (41%) were not. Approximately 49% were female, and median age was 76 years. Antibiotics were associated with reduced risk of major bleeding (adjusted HR 0.38, 95% CI 0.25 to 0.58). This was consistent across several sensitivity analyses. Antibiotics were also associated with a reduced risk of non-major bleeding (adjusted HR 0.78, 95% CI 0.61 to 0.99).

CONCLUSIONS

Immediate antibiotics were associated with reduced risk of bleeding amongst warfarin and DOAC users with an RTI. Further work is needed to understand mechanisms and confirm whether a lower threshold for antibiotic use for RTI in this population may be beneficial.

Enduring echoes: Post-infectious long-term changes in innate immunity

Upon encountering pathogens, the immune system typically responds by initiating an acute and self-limiting reaction, with symptoms subsiding after the pathogen has been cleared. However, long-term post-infectious clinical symptoms can manifest months or even years after the initial infection. 'Trained immunity', the functional reprogramming of innate immune cells through epigenetic and metabolic rewiring, has been proposed as a key concept for understanding these long-term effects. Although trained immunity can result in enhanced protection against reinfection with heterologous pathogens, it can also contribute to detrimental outcomes. Persisting and excessive inflammation can cause tissue damage and aggravate immune-mediated conditions and cardiovascular complications. On the other hand, suppression of immune cell effector functions by long-lasting epigenetic changes can result in post-infectious immune paralysis. Distinct stimuli can evoke different trained immunity programs, potentially resulting in different consequences for the host. In this review, we provide an overview of both the adaptive and maladaptive consequences of infectious diseases. We discuss how long-term immune dysregulation in patients can be addressed by tailoring host-directed interventions and identify areas of scientific and therapeutic potential to advance further.

Cardiovascular disease and risk in COPD: a state of the art review

INTRODUCTION

Chronic Obstructive Pulmonary Disease (COPD) and cardiovascular diseases (CVD) commonly co-exist. Outcomes of people living with both conditions are poor in terms of symptom burden, receiving evidence-based treatment and mortality. Increased understanding of the underlying mechanisms may help to identify treatments to relieve this disease burden. This narrative review covers the overlap of COPD and CVD with a focus on clinical presentation, mechanisms, and interventions. Literature up to December 2023 are cited.

AREAS COVERED

1. What is COPD 2. The co-existence of COPD and cardiovascular disease 3. Mechanisms of cardiovascular disease in COPD. 4. Populations with COPD are at risk of CVD 5. Complexity in the co-diagnosis of COPD in those with cardiovascular disease. 6. Therapy for COPD and implications for cardiovascular events and risk. 7. Cardiovascular risk and exacerbations of COPD. 8. Pro-active identification and management of CV risk in COPD.

EXPERT OPINION

The prospective identification of co-morbid COPD in CVD patients and of CVD and CV risk in people with COPD is crucial for optimizing clinical outcomes. This includes the identification of novel treatment targets and the design of clinical trials specifically designed to reduce the cardiovascular burden and mortality associated with COPD. Databases searched: Pubmed, 2006-2023.

Viral Pneumonia: From Influenza to COVID-19

Respiratory viruses are increasingly recognized as a cause of community-acquired pneumonia (CAP). The implementation of new diagnostic technologies has facilitated their identification, especially in vulnerable population such as immunocompromised and elderly patients and those with severe cases of pneumonia. In terms of severity and outcomes, viral pneumonia caused by influenza viruses appears similar to that caused by non-influenza viruses. Although several respiratory viruses may cause CAP, antiviral therapy is available only in cases of CAP caused by influenza virus or respiratory syncytial virus. Currently, evidence-based supportive care is key to managing severe viral pneumonia. We discuss the evidence surrounding epidemiology, diagnosis, management, treatment, and prevention of viral pneumonia.

Lung endothelium, tau, and amyloids in health and disease

Lung endothelia in the arteries, capillaries, and veins are heterogeneous in structure and function. Lung capillaries in particular represent a unique vascular niche, with a thin yet highly restrictive alveolar-capillary barrier that optimizes gas exchange. Capillary endothelium surveys the blood while simultaneously interpreting cues initiated within the alveolus and communicated via immediately adjacent type I and type II epithelial cells, fibroblasts, and pericytes. This cell-cell communication is necessary to coordinate the immune response to lower respiratory tract infection. Recent discoveries identify an important role for the microtubule-associated protein tau that is expressed in lung capillary endothelia in the host-pathogen interaction. This endothelial tau stabilizes microtubules necessary for barrier integrity, yet infection drives production of cytotoxic tau variants that are released into the airways and circulation, where they contribute to end-organ dysfunction. Similarly, beta-amyloid is produced during infection. Beta-amyloid has antimicrobial activity, but during infection it can acquire cytotoxic activity that is deleterious to the host. The production and function of these cytotoxic tau and amyloid variants are the subject of this review. Lung-derived cytotoxic tau and amyloid variants are a recently discovered mechanism of end-organ dysfunction, including neurocognitive dysfunction, during and in the aftermath of infection.

Estimated Incidence of Hospitalizations and Deaths Attributable to Respiratory Syncytial Virus Infections Among Adults in Germany Between 2015 and 2019

INTRODUCTION

Respiratory syncytial virus (RSV) burden in adults is underestimated mainly due to unspecific symptoms and limited standard-of-care testing. We estimated the population-based incidence of hospitalization and mortality attributable to RSV among adults with and without risk factors in Germany.

METHODS

Weekly counts of hospitalizations and deaths for respiratory, cardiovascular, and cardiorespiratory diseases were obtained (Statutory Health Insurance database, 2015-2019). A quasi-Poisson regression model was fitted to estimate the number of hospitalizations and deaths attributable to RSV as a function of periodic and aperiodic time trends, and viral activity while allowing for potential overdispersion. Weekly counts of RSV and influenza hospitalizations in children < 2 years and adults ≥ 60 years, respectively, were used as viral activity indicators. Models were stratified by age group and risk status (defined as presence of selected comorbidities).

RESULTS

Population-based RSV-attributable hospitalization incidence rates were high among adults ≥ 60 years: respiratory hospitalizations (236-363 per 100,000 person-years) and cardiorespiratory hospitalizations (584-912 per 100,000 person-years). RSV accounted for 2-3% of all cardiorespiratory hospitalizations in this age group. The increase in cardiorespiratory hospitalization risk associated with underlying risk factors was greater in 18-44 year old persons (five to sixfold higher) than in ≥ 75 year old persons (two to threefold higher).

CONCLUSIONS

This is a first model-based study to comprehensively assess adult RSV burden in Germany. Estimated cardiorespiratory RSV hospitalization rates increased with age and were substantially higher in people with risk factors compared to those without risk factors. Our study indicates that RSV, like other respiratory viruses, contributes to both respiratory and cardiovascular hospitalizations. Effective prevention strategies are needed, especially among older adults ≥ 60 years and among adults with underlying risk factors.

Heparin Dose Intensity and Organ Support-Free Days in Patients Hospitalized for COVID-19

Background

Clinical trials suggest that therapeutic-dose heparin may prevent critical illness and vascular complications due to COVID-19, but knowledge gaps exist regarding the efficacy of therapeutic heparin including its comparative effect relative to intermediate-dose anticoagulation.

Objectives

The authors performed 2 complementary secondary analyses of a completed randomized clinical trial: 1) a prespecified per-protocol analysis; and 2) an exploratory dose-based analysis to compare the effect of therapeutic-dose heparin with low- and intermediate-dose heparin.

Methods

Patients who received initial anticoagulation dosed consistently with randomization were included. The primary outcome was organ support-free days (OSFDs), a combination of in-hospital death and days free of organ support through day 21.

Results

Among 2,860 participants, 1,761 (92.8%) noncritically ill and 857 (89.1%) critically ill patients were treated per-protocol. Among noncritically ill per-protocol patients, the posterior probability that therapeutic-dose heparin improved OSFDs as compared with usual care was 99.3% (median adjusted OR: 1.36; 95% credible interval [CrI]: 1.07-1.74). Therapeutic heparin had a high posterior probability of efficacy relative to both low- (94.6%; adjusted OR: 1.26; 95% CrI: 0.95-1.64) and intermediate- (99.8%; adjusted OR: 1.80; 95% CrI: 1.22-2.62) dose thromboprophylaxis. Among critically ill per-protocol patients, the posterior probability that therapeutic heparin improved outcomes was low.

Conclusions

Among noncritically ill patients hospitalized for COVID-19 who were randomized to and initially received therapeutic-dose anticoagulation, heparin, compared with usual care, was associated with improved OSFDs, a combination of in-hospital death and days free of organ support. Therapeutic heparin appeared superior to both low- and intermediate-dose thromboprophylaxis.

Estimated Respiratory Syncytial Virus-Related Hospitalizations and Deaths Among Children and Adults in Spain, 2016-2019

INTRODUCTION

Respiratory syncytial virus (RSV) causes a substantial disease burden among infants. In older children and adults, incidence is underestimated due to nonspecific symptoms and limited standard-of-care testing. We aimed to estimate RSV-attributable hospitalizations and deaths in Spain during 2016-2019.

METHODS

Nationally representative hospitalization and mortality databases were obtained from the Ministry of Health and the National Statistical Office. A quasi-Poisson regression model was fitted to estimate the number of hospitalizations and deaths attributable to RSV as a function of periodic and aperiodic time trends and viral activity, while allowing for potential overdispersion.

RESULTS

In children, the RSV-attributable respiratory hospitalization incidence was highest among infants aged 0-5 months (3998-5453 cases/100,000 person-years, representing 72% of all respiratory hospitalizations) and decreased with age. In 2019, estimated rates in children 0-5, 6-11, 12-23 months and 6-17 years were approximately 1.3, 1.4, 1.5, and 6.5 times higher than those based on standard-of-care RSV-specific codes. In adults, the RSV-attributable cardiorespiratory hospitalization rate increased with age and was highest among persons ≥ 80 years (1325-1506 cases/100,000, 6.5% of all cardiorespiratory hospitalizations). In 2019, for persons aged 18-49, 50-59, 60-79, and ≥ 80 years, estimated rates were approximately 8, 6, 8, and 16 times higher than those based on standard-of-care RSV-specific codes. The RSV-attributable cardiorespiratory mortality rate was highest among ≥ 80 age group (126-150 deaths/100,000, 3.5-4.1% of all cardiorespiratory deaths), when reported mortality rate ranged between 0 and 0.5/100,000.

CONCLUSIONS

When accounting for under-ascertainment, estimated RSV-attributable hospitalizations were higher than those reported based on standard-of-care RSV-specific codes in all age groups but particularly among older children and older adults. Like other respiratory viruses, RSV contributes to both respiratory and cardiovascular complications. Efficacious RSV vaccines could have a high public health impact in these age and risk groups.

Vaccines and Myocardial Injury in Patients Hospitalized for COVID-19 Infection: the CardioCOVID-Gemelli Study

BACKGROUND

Myocardial injury is prevalent among patients hospitalized for COVID-19. However, the role of COVID-19 vaccines in modifying the risk of myocardial injury is unknown.

OBJECTIVES

To assess the role of vaccines in modifying the risk of myocardial injury in COVID-19.

METHODS

We enrolled COVID-19 patients admitted from March 2021 to February 2022 with known vaccination status and ≥1 assessment of hs-cTnI within 30 days from the admission. The primary endpoint was the occurrence of myocardial injury (hs-cTnI levels >99th percentile upper reference limit).

RESULTS

1019 patients were included (mean age 67.7±14.8 years, 60.8% male, 34.5% vaccinated against COVID-19). Myocardial injury occurred in 145 (14.2%) patients. At multivariate logistic regression analysis, advanced age, chronic kidney disease and hypertension, but not vaccination status, were independent predictors of myocardial injury. In the analysis according to age tertiles distribution, myocardial injury occurred more frequently in the III tertile (≥76 years) compared to other tertiles (I tertile:≤60 years;II tertile:61-75 years) (p<0.001). Moreover, in the III tertile, vaccination was protective against myocardial injury (OR 0.57, CI 95% 0.34-0.94; p=0.03), while a previous history of coronary artery disease was an independent positive predictor. In contrast, in the I tertile, chronic kidney disease (OR 6.94, 95% CI 1.31-36.79, p=0.02) and vaccination (OR 4.44, 95% CI 1.28-15.34, p=0.02) were independent positive predictors of myocardial injury.

CONCLUSIONS

In patients ≥76 years, COVID-19 vaccines were protective for the occurrence of myocardial injury, while in patients ≤60 years, myocardial injury was associated with previous COVID-19 vaccination. Further studies are warranted to clarify the underlying mechanisms.

Protective Effects of Liriodendrin on Myocardial Infarction-Induced Fibrosis in Rats via the PI3K/Akt Autophagy Pathway: A Network Pharmacology Study

BACKGROUND

Liriodendrin (LIR) has been reported to improve cardiac function in rats following myocardial infarction. However, its role and mechanism in reparative myocardial fibrosis remain unclear.

METHODS

In this study, a rat model of myocardial fibrosis was established via left anterior descending artery ligation and randomly divided into three groups (n = 6 per group): sham-operated, myocardial infarction, and LIR intervention (100 mg/kg/day) groups. The pharmacological effects of LIR were assessed using echocardiography, hematoxylin, and eosin (H&E) staining, and Masson staining. Network pharmacology and bioinformatics were utilized to identify potential mechanisms of LIR, which were further validated via western blot analysis.

RESULTS

Our findings demonstrated that LIR improved cardiac function, histology scores, and col lagen volume fraction. Moreover, LIR downregulated the expression of Beclin-1, LC3-II/LC3-I while upregulating the expression of p62, indicating LIR-inhibited autophagy in the heart after myocardial infarction. Further analysis revealed that the PI3K/Akt signaling pathway was significantly enriched and validated by western blot. This analysis suggested that the ratios of p- PI3K/PI3K, p-Akt/Akt, and p-mTOR/mTOR were significantly increased.

CONCLUSION

LIR may attenuate myocardial infarction-induced fibrosis in rats by inhibiting excessive myocardial autophagy, with the potential mechanism involving the activation of the PI3K/Akt/mTOR pathway.

Temporary Mechanical Circulatory Support in Sepsis-Associated Cardiogenic Shock With and Without Acute Myocardial Infarction

OBJECTIVES

To describe the current use and outcomes of temporary mechanical circulatory support (MCS) in patients with sepsis-associated cardiogenic shocks with and without acute myocardial infarction (AMI) in the United States.

DESIGN

Retrospective cohort study.

SETTING

The National Inpatient Sample database from 2017 to 2019.

PARTICIPANTS

Adult patients with sepsis-associated cardiogenic shock with and without AMI.

INTERVENTIONS

Temporary MCSs, including intra-aortic balloon pump (IABP), percutaneous left ventricular assist device (pLVAD), and extracorporeal membrane oxygenation (ECMO).

MEASUREMENTS AND MAIN RESULTS

Multivariate logistic regression analyses adjusting for patient characteristics, organ failures, and socioeconomic status. Although the uses of IABP and pLVAD were associated with significantly lower odds of in-hospital mortality in patients with sepsis-associated cardiogenic shock (IABP: adjusted odds ratio [aOR] 0.57, 95% CI 0.44-0.73, p < .001; pLVAD: aOR 0.66, 95% CI 0.45-0.98, p = .037), ECMO was not (aOR 1.51, 95% CI 0.93-2.45, p = 0.096). In the subgroup with AMI, temporary MCSs were not associated with significantly lower or higher odds of in-hospital mortality. In the subgroup without AMI, IABP was associated with significantly lower odds of in-hospital mortality (aOR 0.43, 95% CI 0.28-0.65, p < 0.001).

CONCLUSIONS

Although temporary MCS is deemed to be a feasible option in sepsis-associated cardiogenic shock, the selection of the right patients whose shock is driven mainly by cardiogenic shock rather than septic shock, as represented by low cardiac output and high systemic vascular resistance, plays a critical role in the feasibility of this approach in the absence of clinical trials.

Cardiac injury in hospitalized patients with severe fever and thrombocytopenia syndrome

Severe fever with thrombocytopenia syndrome (SFTS), an emerging infectious disease with a high fatality rate. Cardiac injury in SFTS patients is a major concern. This study aimed to evaluate the prevalence of cardiac injury and its association with mortality in hospitalized patients infected with novel Bunyavirus. Cardiac injury was defined as the presence of any of the following abnormalities: (1) blood levels of cardiac biomarkers (creatine kinase-MB, troponin-I, B-type natriuretic peptide or N-terminal pro-B-type natriuretic peptide); (2) new abnormalities in electrocardiography. The 203 SFTS patients were included in the final analysis. The proportion of SFTS patients developing cardiac injury during hospitalization was 71.4% (145/203). Compared with the uninjured group, the cardiac injury group had the severity of cardiac injury was underscored by higher median hospital costs (31420 vs. 12911, p < 0.001), higher proportion of intensive care units admissions (13.1% vs. 3.4%, p = 0.041), and higher hospital mortality rate (33.8% vs. 6.9%, p < 0.001). Multivariable-adjusted Cox proportional hazards regression analysis showed that cardiac injury was associated with higher mortality during hospitalization (hazards ratio, 7.349; 95% CI: 2.352-22.960). Cardiac injury is common among hospitalized SFTS patients, and it is associated with higher risk of mortality.

Risk Factors for 30-Day Mortality in Patients with Bacteremic Pneumonia Caused by Escherichia coli and Klebsiella pneumoniae: A Retrospective Study

Objective

Escherichia coli and Klebsiella pneumoniae are prevalent Gram-negative microorganisms responsible for pneumonia, as well as the primary Enterobacteriaceae pathogens causing bacteremic pneumonia. The objective of this research is to analyze the risk factors associated with bacteremic pneumonia caused by these pathogens and develop a predictive model.

Patients and Methods

This retrospective investigation encompassed a cohort of 252 patients diagnosed with Escherichia coli or Klebsiella pneumoniae-induced bacteremic pneumonia between 2018 and 2022. The primary endpoint was 30-day mortality, which was analyzed using multifactorial logistic regression, nomogram construction, and Bootstrap validation.

Results

Among the 252 patients diagnosed with Escherichia coli and Klebsiella pneumoniae, 65 succumbed to the disease while 187 survived. The overall 30-day mortality was found to be 25.8%. A multifactorial logistic regression analysis revealed that diastolic blood pressure, cerebrovascular diseases/transient ischemic attacks (TIA), immunosuppression, blood urea nitrogen, Pitt score, and CURB-65 score were statistically significant factors. The Nomogram model demonstrated an AUC of 0.954, which closely aligns with the Bootstrap-derived mean AUC of 0.953 (95% CI: 0.952-0.954).

Conclusion

In patients with bacteremic pneumonia caused by Escherichia coli and Klebsiella pneumoniae, Low diastolic blood pressure (≤61 mmHg), pre-existing cerebrovascular disease/ transient ischemic attacks (TIA), immunosuppression status, elevated blood urea nitrogen levels (≥8.39 mmol/L), high Pitt score (≥3), and a high CURB-65 score (≥2) are all independent risk factors for Escherichia coli and Klebsiella pneumoniae bacteremic pneumonia, among which the first three warrant particular attention.

Diagnostic and prognostic impact of new pathophysiology-based categorization of type 1 and type 2 myocardial infarction: data from the French RICO survey

BACKGROUND

A new classification of type 1 and 2 myocardial infarction (MI) derived from the fourth universal definition of MI (UDMI) has been recently proposed, based on pathophysiology of coronary artery disease (CAD). We assessed the impact of this new MI categorization on epidemiology and outcomes, considering type 1 MI (T1MI) and type 2 MI (T2MI), with and without CAD.

METHODS

Retrospective study including all consecutive patients hospitalized for an acute MI in a multicenter database (RICO). MI was defined according to current UDMI. Rates and outcomes of T1MI and T2MI were addressed according to the new classification.

RESULTS

Among the 4,573 patients included in our study, 3,710 patients (81.1%) were initially diagnosed with T1M1 and 863 (18.9%) with T2MI. After reclassification, 96 T2MI patients were moved into the T1MI category. Out of the remaining 767 patients with T2MI, 567 underwent coronary angiography, and were adjudicated as type 2A MI (68.6%) with obstructive CAD, and type 2B MI (31.4%) without obstructive CAD. When compared with T1MI and T2BMI, T2AMI patients had worse in-hospital outcomes, including severe heart failure (P < .001), atrial fibrillation or flutter (P < .001) and severe bleeding (P < .001). Kaplan-Meier 1-year survival curves showed higher all-cause and CV causes mortality in T2AMI patients compared to T1MI and T2BMI (P < .001). In multivariate Cox regression analysis, type of MI was independent predictor of death.

CONCLUSION

Our large observational multicenter study shows major disparities in mortality according to type of MI and support the relevance of the new MI classification to improve risk classification, taking into account CAD in T2MI. Our findings may help identifying specific phenotypes and considering personalized diagnostic and management strategies.

The Trend of Arrhythmias in Patients With COVID-19: A Complication or Late Manifestation?

Patients diagnosed with coronavirus disease (CVD) who experience cardiovascular complications or have pre-existing cardiovascular disease are at an increased risk of death. The primary heart-related consequences associated with COVID-19 encompass venous thromboembolism, shock, heart failure, arrhythmias, myocarditis, acute myocardial infarction, and acute cardiac damage. The coronavirus has the potential to induce cardiovascular complications or exacerbate pre-existing CVD through various mechanisms. These mechanisms include dysregulation of the renin-angiotensin-aldosterone system; direct viral toxicity; damage to endothelial cells; formation of blood clots and subsequent inflammation, a phenomenon known as thromboinflammation; an excessive immune response known as cytokine storm; and an imbalance between the demand and supply of oxygen in the body. In this study, we comprehensively analyze the cardiovascular symptoms, histology, and underlying mechanisms associated with COVID-19. Our aim is to contribute to the identification of future research objectives and aid in the advancement of therapeutic management approaches.

An Update on Inflammation in Atherosclerosis: How to Effectively Treat Residual Risk

PURPOSE

This study reviewed the contribution of inflammation to atherosclerotic cardiovascular disease (ASCVD), which has gained widespread recognition in recent years.

METHODS

This critical review evaluated how recent publications and ongoing clinical trials in atherosclerotic inflammation will affect clinical care.

FINDINGS

Key trials, including CANTOS (Canakinumab Anti-Inflammatory Thrombosis Outcomes Study) with canakinumab (interleukin-1β inhibition), and COLCOT (Colchicine Cardiovascular Outcomes Trial) and LoDoCo2 (Low Dose Colchicine 2) with colchicine, have shown that suppressing inflammation can improve outcomes in ASCVD. Cholesterol crystals play an important role in activating the NOD-, LRR-, and pyrin domain-containing protein 3 inflammasome and subsequent cytokine cascade. Inflammation contributes to significant residual risk after optimal lipid-lowering therapy. High-sensitivity C-reactive protein is a recognized biomarker of residual risk, and newer biomarkers such as the neutrophil to lymphocyte ratio may add additional information. The role of lipoprotein(a) as a proinflammatory agent or possible inflammatory biomarker is under investigation. The contribution of clonal hematopoiesis of indeterminate potential and trained immunity are in the early stages of investigation. Ongoing clinical trials of suppressing inflammation with NOD-, LRR-, and pyrin domain-containing protein 3 inflammasome inhibition (colchicine) and alternative approaches with downstream interleukin-6 ligand inhibition (ziltivekimab) will expand the evidence base for the use of anti-inflammatory agents in ASCVD.

IMPLICATIONS

Based on current evidence and ongoing clinical trials, targeting inflammation alongside optimal lipid lowering is likely to be central to the future treatment of ASCVD. (Clin Ther. 2023;45:XXX-XXX) © 2023 Elsevier HS Journals, Inc.

Myocarditis manifestations in dengue cases: A systematic review and meta-analysis

BACKGROUND

Dengue fever is a zoonotic viral infection that raises a global alarm in the tropics and subtropics, with the potentially escalating into newer geographical regions. Severe dengue may be associated with fatal complications such as myocarditis. There is a paucity of available data on the prevalence of dengue-associated myocarditis. The objective of this systematic review and meta-analysis was to estimate the global prevalence of dengue-associated myocarditis.

METHODS

A systematic search was conducted utilizing the Cochrane library, PubMed, Scopus, ProQuest, Web of Science, and Preprint servers such as arXiv, medRxiv, bioRxiv, BioRN, ChiRN, ChiRxiv, and SSRN as of November 25, 2022. All primary studies (case series, cross-sectional, retrospective, and prospective) that reported confirmed cases of dengue myocarditis were included. The I2 statistic test assessed the heterogenic characteristics and publication bias was evaluated using Doi plot and Egger regression tests.

RESULTS

A total of 12 studies conducted between 2007 and 2022 with 2795 laboratory-confirmed dengue patients were included. Of the included cases, 502 were positive for myocarditis, with a prevalence of 2.4-78%. The pooled prevalence of dengue-induced myocarditis in the studied population was 21.0% (95% CI, 9 - 38%). The prediction interval was estimated to be 0.00 - 0.81.

CONCLUSION

Myocarditis in dengue patients is a significant and understudied complication in many aspects. To prevent dengue-associated myocarditis, appropriate measures such as early detection of cases and signs, symptoms-based diagnosis via electrocardiography and echocardiography, as well as relevant vector control policies must be implemented.

Mesenchymal Stem Cells in the Treatment of COVID-19

Since the emergence of the coronavirus disease 2019 (COVID-19) pandemic, many lives have been tragically lost to severe infections. The COVID-19 impact extends beyond the respiratory system, affecting various organs and functions. In severe cases, it can progress to acute respiratory distress syndrome (ARDS) and multi-organ failure, often fueled by an excessive immune response known as a cytokine storm. Mesenchymal stem cells (MSCs) have considerable potential because they can mitigate inflammation, modulate immune responses, and promote tissue regeneration. Accumulating evidence underscores the efficacy and safety of MSCs in treating severe COVID-19 and ARDS. Nonetheless, critical aspects, such as optimal routes of MSC administration, appropriate dosage, treatment intervals, management of extrapulmonary complications, and potential pediatric applications, warrant further exploration. These research avenues hold promise for enriching our understanding and refining the application of MSCs in confronting the multifaceted challenges posed by COVID-19.

Understanding Post-Sepsis Syndrome: How Can Clinicians Help?

Sepsis is a global health challenge, with over 49 million cases annually. Recent medical advancements have increased in-hospital survival rates to approximately 80%, but the escalating incidence of sepsis, owing to an ageing population, rise in chronic diseases, and antibiotic resistance, have also increased the number of sepsis survivors. Subsequently, there is a growing prevalence of "post-sepsis syndrome" (PSS). This syndrome includes long-term physical, medical, cognitive, and psychological issues after recovering from sepsis. PSS puts survivors at risk for hospital readmission and is associated with a reduction in health- and life span, both at short and long term, after hospital discharge. Comprehensive understanding of PSS symptoms and causative factors is vital for developing optimal care for sepsis survivors, a task of prime importance for clinicians. This review aims to elucidate our current knowledge of PSS and its relevance in enhancing post-sepsis care provided by clinicians.

The first case report of acute myocardial infarction in young adult caused by scrub typhus

RATIONALE

Scrub typhus is a zoonotic disease caused by Orientia tsutsugamushi, a gram-negative intracellular bacterium and endemic in Asia-Pacific area. Acute myocardial infarction after Oricntia tsutsugamushi infection was rarely reported, and young adult was not reported.

PATIENT CONERNS

A 33-year-old man came to the emergency complained with chest tightness and fever for 4 days.

DIAGONOSES

After Weil-Felix agglutination test (titer 1:160) twice, scrub typhus was diagnosed.

INTERVENTIONS

After treating with a hormonotherapy, antibiotic and ventilator-assisted ventilation, his chest tightness was mild lessened with normal breath and body temperature. However, an emergent coronary angiography performed unnormal, then a percutaneous coronary intervention was realized with the implantation of a stent.

OUTCOMES

After the surgeon, his chest tightness was totally released, and he was discharged.

LESSONS

Our case was the first report of young adult acute myocardial infarction after O tsutsugamushi infection and we tried to figure out the potential mechanism and how to deal with.

Potential Effects of Traditional Chinese Medicine on COVID-19 and Cardiac Injury: Mechanisms and Clinical Evidence

Coronavirus disease 2019 is a "Public Health Emergency of International Concern" from 30 January 2020 to 5 May 2023. While battling Coronavirus disease 2019, the Chinese government has actively promoted the collaborative treatment model of Western medicine and traditional Chinese medicine, and clinical and scientific research has applied appropriate and rigorous methodology. Severe acute respiratory syndrome coronavirus 2 infection may damage the cardiovascular system via an unclarified pathogenic mechanism. The National Health Commission of China recommends 'three formulas and three medicines' for the treatment of coronavirus disease 2019, which have been shown to be most effective in the treatments. Data from randomized controlled trials of 'three formulas and three medicines' suggested that the traditional Chinese medicine is safe and can alleviate the symptoms of cardiac injury. Therefore, we further evaluate the benefits and safety of traditional Chinese medicine treatment for Coronavirus disease 2019 patients with cardiac injury across the care continuum.

A Methylene Blue-Enhanced Nanostructured Electrochemical Immunosensor for H-FABP Myocardial Injury Biomarker

A sensitive electrochemical immunosensor for the detection of the heart-type fatty acid binding protein (HFABP), an earlier biomarker for acute myocardial infarction than Troponins, is described. The sensing platform was enhanced with methylene blue (MB) redox coupled to carbon nanotubes (CNT) assembled on a polymer film of polythionine (PTh). For this strategy, monomers of thionine rich in amine groups were electrosynthesized by cyclic voltammetry on the immunosensor's gold surface, forming an electroactive film with excellent electron transfer capacity. Stepwise sensor surface preparation was electrochemically characterized at each step and scanning electronic microscopy was carried out showing all the preparation steps. The assembled sensor platform combines MB and PTh in a synergism, allowing sensitive detection of the H-FABP in a linear response from 3.0 to 25.0 ng∙mL-1 with a limit of detection of 1.47 ng∙mL-1 HFABP that is similar to the clinical level range for diagnostics. H-FABP is a newer powerful biomarker for distinguishing between unstable angina and acute myocardial infarction.

Temporal Trends in Noncardiovascular Morbidity and Mortality Following Acute Myocardial Infarction

BACKGROUND

Due to improved management, diagnosis, and care of myocardial infarction (MI), patients may now survive long enough to increasingly develop serious noncardiovascular conditions.

OBJECTIVES

This study aimed to test this hypothesis by investigating the temporal trends in noncardiovascular morbidity and mortality following MI.

METHODS

We conducted a registry-based nationwide cohort study of all Danish patients with MI during 2000 to 2017. Outcomes were cardiovascular and noncardiovascular mortality, incident cancer, incident renal disease, and severe infectious disease.

RESULTS

From 2000 to 2017, 136,293 consecutive patients were identified (63.2% men, median age 69 years). The 1-year risk of cardiovascular mortality between 2000 to 2002 and 2015 to 2017 decreased from 18.4% to 7.6%, whereas noncardiovascular mortality decreased from 5.8% to 5.0%. This corresponded to an increase in the proportion of total 1-year mortality attributed to noncardiovascular causes from 24.1% to 39.5%. Furthermore, increases in 1-year risk of incident cancer (1.9%-2.4%), incident renal disease (1.0%-1.6%), and infectious disease (5.5%-9.1%) were observed (all P trend <0.01). In analyses standardized for changes in patient characteristics, the increased risk of cancer in 2015 to 2017 compared with 2000 to 2002 was no longer significant (standardized risk ratios for cancer: 0.99 [95% CI: 0.91-1.07]; renal disease: 1.28 [95% CI: 1.15-1.41]; infectious disease: 1.28 [95% CI: 1.23-1.34]).

CONCLUSIONS

Although cardiovascular mortality following MI improved substantially during 2000 to 2017, the risk of noncardiovascular morbidity increased. Moreover, noncardiovascular causes constitute an increasing proportion of post-MI mortality. These findings suggest that further attention on noncardiovascular outcomes is warranted in guidelines and clinical practice and should be considered in the design of future clinical trials.

Influenza vaccination and cardiovascular events in patients with ischaemic heart disease and heart failure: A meta-analysis

AIM

Randomized controlled trials (RCTs) enrolling patients at high cardiovascular risk have found that influenza vaccination may reduce the incidence of cardiovascular events. We performed an updated meta-analysis assessing the effect of influenza vaccination on the incidence of cardiovascular events in patients with ischaemic heart disease or heart failure.

METHODS AND RESULTS

We searched PubMed, EMBASE and other sources to identify RCTs examining the effect of influenza vaccination on the incidence of cardiovascular events assessed as efficacy outcomes in patients with ischaemic heart disease or heart failure. Eligible studies followed patients for at least one influenza season, defined as a minimum duration of 6 months. The primary endpoint was a composite of cardiovascular death, acute coronary syndrome, stent thrombosis or coronary revascularization, stroke or heart failure hospitalization. The secondary endpoints were cardiovascular death and all-cause death. Two investigators independently identified and extracted data from studies. Results were compared using hazard ratios (HRs) in both random effects and fixed effects models. We included five peer-reviewed and one non peer-reviewed RCTs for a total of 9340 patients. Five trials included patients with ischaemic heart disease (n = 4211) and one trial included patients with heart failure (n = 5129). Influenza vaccination was associated with a reduced incidence of the primary composite endpoint (random effects HR [rHR] 0.74, 95% confidence interval [CI] 0.63-0.88, p < 0.001, I2  = 52%), cardiovascular death (rHR 0.63, 95% CI 0.42-0.95, p = 0.028, I2  = 58%) and all-cause death (rHR 0.72, 95% CI 0.54-0.95, p = 0.0227, I2  = 52%). Results were similar when non peer-reviewed data were excluded.

CONCLUSION

In this meta-analysis of available RCTs in patients at high cardiovascular risk, influenza vaccination was associated with a reduced incidence of cardiovascular events, cardiovascular death and all-cause death as compared to placebo or no treatment.

Gamma secretase activating protein promotes end-organ dysfunction after bacterial pneumonia

Pneumonia elicits the production of cytotoxic beta amyloid (Aβ) that contributes to end-organ dysfunction, yet the mechanism(s) linking infection to activation of the amyloidogenic pathway that produces cytotoxic Aβ is unknown. Here, we tested the hypothesis that gamma-secretase activating protein (GSAP), which contributes to the amyloidogenic pathway in the brain, promotes end-organ dysfunction following bacterial pneumonia. First-in-kind Gsap knockout rats were generated. Wild-type and knockout rats possessed similar body weights, organ weights, circulating blood cell counts, arterial blood gases, and cardiac indices at baseline. Intratracheal Pseudomonas aeruginosa infection caused acute lung injury and a hyperdynamic circulatory state. Whereas infection led to arterial hypoxemia in wild-type rats, the alveolar-capillary barrier integrity was preserved in Gsap knockout rats. Infection potentiated myocardial infarction following ischemia-reperfusion injury, and this potentiation was abolished in knockout rats. In the hippocampus, GSAP contributed to both pre- and postsynaptic neurotransmission, increasing the presynaptic action potential recruitment, decreasing neurotransmitter release probability, decreasing the postsynaptic response, and preventing postsynaptic hyperexcitability, resulting in greater early long-term potentiation but reduced late long-term potentiation. Infection abolished early and late long-term potentiation in wild-type rats, whereas the late long-term potentiation was partially preserved in Gsap knockout rats. Furthermore, hippocampi from knockout rats, and both the wild-type and knockout rats following infection, exhibited a GSAP-dependent increase in neurotransmitter release probability and postsynaptic hyperexcitability. These results elucidate an unappreciated role for GSAP in innate immunity and highlight the contribution of GSAP to end-organ dysfunction during infection.NEW & NOTEWORTHY Pneumonia is a common cause of end-organ dysfunction, both during and in the aftermath of infection. In particular, pneumonia is a common cause of lung injury, increased risk of myocardial infarction, and neurocognitive dysfunction, although the mechanisms responsible for such increased risk are unknown. Here, we reveal that gamma-secretase activating protein, which contributes to the amyloidogenic pathway, is important for end-organ dysfunction following infection.

COVID-19 and Acute Cardiac Injury: Clinical Manifestations, Biomarkers, Mechanisms, Diagnosis, and Treatment

PURPOSE OF REVIEW

This review aims to comprehensively explore the clinical characteristics of COVID-19-related cardiac injury and examine the potential mechanisms underlying cardiac injury in patients affected by COVID-19.

RECENT FINDINGS

The COVID-19 pandemic has primarily been associated with severe respiratory symptoms. However, emerging evidence has indicated that a significant number of COVID-19 patients also experience myocardial injury, leading to conditions such as acute myocarditis, heart failure, acute coronary syndrome, and arrhythmias. The incidence of myocardial injury is notably higher in patients with preexisting cardiovascular diseases. Myocardial injury often manifests with elevated levels of inflammation biomarkers, as well as abnormalities observed on electrocardiograms and echocardiograms. COVID-19 infection has been found to be associated with myocardial injury, which can be attributed to several pathophysiological mechanisms. These mechanisms include injury caused by hypoxia, resulting from respiratory compromise, a systemic inflammatory response triggered by the infection, and direct attack on the myocardium by the virus itself. Furthermore, the angiotensin-converting enzyme 2 (ACE2) receptor plays a crucial role in this process. Early recognition, prompt diagnosis, and a comprehensive understanding of the underlying mechanisms are essential for effectively managing and reducing the mortality associated with myocardial injury in COVID-19 patients.

Extracorporeal membrane oxygenation for COVID-19-associated acute respiratory distress syndrome: A nationwide analysis

Extracorporeal membrane oxygenation (ECMO) has been used for COVID-19-associated acute respiratory distress syndrome (ARDS). We aimed to elucidate the association between ECMO and mortality in patients with COVID-19-associated ARDS in the nationwide setting. United States National Inpatient Sample was used to identify mechanically ventilated adults for COVID-19 with ARDS. We divided them into three groups according to the use of ECMO (i.e., no-ECMO, venovenous [VV]-ECMO, and venoarterial [VA]-ECMO). The primary outcome was in-hospital mortality, while the secondary outcomes included the length of hospital stay (LOS) and the total costs during hospitalization. We performed a stepwise logistic regression, adjusting for baseline characteristics, comorbidities, and severity. We included 68 795 (mean age [SD]: 63.5 [0.1]), 3280 (mean age [SD]: 48.7 [0.5]), and 340 (mean age [SD]: 43.3 [2.1]) patients who received no-, VV-, and VA-ECMO, respectively. The logistic regression analysis did not show significant associations between the use of VV-/VA-ECMO and mortality (adjusted odds ratio with no-ECMO as reference [95% confidence interval]: 1.03 [0.86-1.24] and 1.18 [0.64-2.15], respectively). While LOS was longest with VV-ECMO, the total costs were highest with VA-ECMO. In conclusion, our study found no association between the use of ECMO and mortality of COVID-19-associated ARDS in the nationwide setting.

Interventions to improve outcomes in community-acquired pneumonia

INTRODUCTION

Community-acquired pneumonia (CAP) is a common infection associated with high morbimortality and a highly deleterious impact on patients' quality of life and functionality. We comprehensively review the factors related to the host, the causative microorganism, the therapeutic approach and the organization of health systems (e.g. setting for care and systems for allocation) that might have an impact on CAP-associated outcomes. Our main aims are to discuss the most controversial points and to provide some recommendations that may guide further research and the management of patients with CAP, in order to improve their outcomes, beyond mortality.

AREA COVERED

In this review, we aim to provide a critical account of potential measures to improve outcomes of CAP and the supporting evidence from observational studies and clinical trials.

EXPERT OPINION

CAP is associated with high mortality and a highly deleterious impact on patients' quality of life. To improve CAP-associated outcomes, it is important to understand the factors related to the patient, etiology, therapeutics, and the organization of health systems.

Risk of Acute Myocardial Infarction Among Patients With Laboratory-Confirmed Invasive Pneumococcal Disease: A Self-Controlled Case Series Study

BACKGROUND

Acute myocardial infarction (AMI) events have been reported among patients with certain viral and bacterial infections. Whether invasive pneumococcal disease (IPD) increases the risk of AMI remains unclear. We examined whether laboratory-confirmed IPD was associated with the risk of AMI.

METHODS

We conducted a self-controlled case series analysis among adult Tennessee residents with evidence of an AMI hospitalization (2003-2019). Patient follow-up started 1 year before the earliest AMI and continued through the date of death, 1 year after AMI, or study end (December 2019). Periods for AMI assessment included the 7 to 1 days before IPD specimen collection (pre-IPD detection), day 0 through day 7 after IPD specimen collection (current IPD), day 8 to 28 after IPD specimen collection (post-IPD), and a control period (all other follow-up). We used conditional Poisson regression to calculate incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for each risk period compared with control periods using within-person comparisons.

RESULTS

We studied 324 patients hospitalized for AMI with laboratory-confirmed IPD within 1 year before or after the AMI hospitalization. The incidence of AMI was significantly higher during the pre-IPD detection (IRR, 10.29; 95% CI: 6.33-16.73) and the current IPD (IRR, 92.95; 95% CI: 72.17-119.71) periods but nonsignificantly elevated in the post-IPD risk period (IRR, 1.83; 95% CI: .86-3.91) compared with control periods. The AMI incidence was higher in the post-IPD control period (29 to 365 days after IPD; IRR, 2.95; 95% CI: 2.01-4.32).

CONCLUSIONS

Hospitalizations with AMI were strongly associated with laboratory-confirmed IPD.

Literature Review-Transthoracic Echocardiography, Computed Tomography Angiography, and Their Value in Clinical Decision Making and Outcome Predictions in Patients with COVID-19 Associated Cardiovascular Complications

The sudden outbreak of the COVID-19 pandemic posed a great threat to the world's healthcare systems. It resulted in the development of new methods and algorithms for the diagnosis and treatment of both COVID-19 and its complications. Diagnostic imaging played a crucial role in both cases. Among the most widely used examinations are transthoracic echocardiography (TTE) and computed tomography angiography (CTA). Cardiovascular complications in COVID-19 are frequently associated with a severe inflammatory response, which results in acute respiratory failure, further leading to severe complications of the cardiovascular system. Our review aims to discuss the value of TTE and CTA in clinical decision making and outcome prediction in patients with COVID-19-associated cardiovascular complications. Our review revealed the high clinical value of various TTE findings and their association with mortality and the prediction of patients' clinical outcomes, especially when used with other laboratory parameters. The strongest association between increased mortality and findings in TTE was observed for tachycardia and decreased left ventricular ejection fraction (odds ratio (OR) 24.06) and tricuspid annular plane systolic excursion/pulmonary artery systolic pressure ratio (TAPSE/PASP ratio) < 0.31 mm/mmHg (OR 17.80). CTA is a valuable tool in diagnosing COVID-19-associated pulmonary embolism, but its association with mortality and its predictive role should always be combined with laboratory findings and patients' medical history. D-dimers > 3000 ng/mL were found as the strongest predictors of pulmonary embolism (PE) (OR 7.494). Our review indicates the necessity for an active search for cardiovascular complications in patients with severe COVID-19, as they are linked with an increased probability of fatal outcomes.

An Evolving Understanding of the Basis and Management of Vascular Complications of COVID-19: Where Do We Go From Here?

The COVID-19 pandemic led to millions of deaths worldwide after its emergence in 2020. The SARS-CoV-2 virus primarily affects respiratory function, but immune dysregulation leading to systemic inflammation, endothelial dysfunction, and coagulopathy can predispose to systemic complications including hematologic and vascular complications. Treatment strategies for patients with COVID-19 have rapidly evolved and the effectiveness and safety of antithrombotic agents have been evaluated in multiple clinical trials. The findings have spurred interest in the prevention and treatment of the hematologic and vascular complications of non-COVID-19 respiratory infections. This review is focused on hematological and vascular complications of COVID-19, including their pathophysiology, clinical manifestations, and management. Because of the perpetually changing nature of the disease, the review places previous data in temporal contexts and outlines potential next steps for future research in COVID-19 and other severe respiratory infections.

Effects of Bacillus Calmette-Guérin on immunometabolism, microbiome and liver diseases⋆

Metabolic diseases have overtaken infectious diseases as the most serious public health issue and economic burden in most countries. Moreover, metabolic diseases increase the risk of having infectious diseases. The treatment of metabolic disease may require a long-term strategy of taking multiple medications, which can be costly and have side effects. Attempts to expand the therapeutic use of vaccination to prevent or treat metabolic diseases have attracted significant interest. A growing body of evidence indicates that Bacillus Calmette-Guérin (BCG) offers protection against non-infectious diseases. The non-specific effects of BCG occur likely due to the induction of trained immunity. In this regard, understanding how BCG influences the development of chronic metabolic health including liver diseases would be important. This review focuses on research on BCG, the constellation of disorders associated with metabolic health issues including liver diseases and diabetes as well as how BCG affects the gut microbiome, immunity, and metabolism.

The Presence of Pneumonia Is Strongly Associated With Higher Prevalence of Non-ST-Elevation Myocardial Infarction Using a Large NIS Database

OBJECTIVE

Inflammation is a risk factor for myocardial infarction. Pneumonia leads to severe inflammatory response. Some studies suggest higher risk of myocardial infarction in patients with pneumonia. We used a large inpatient database (National Inpatient Sample) to evaluate this association.

METHODS

This study includes patients from a Nationwide Inpatient Sample hospital in 2005 to 2014 with International Classification of Diseases, Ninth Revision, and Clinical Modification codes consistent with pneumonia and non-ST elevation myocardial infarction (NSTEMI). Subjects were stratified into all hospitalized patients aged 30 and above. Univariate and multivariate analysis was performed adjusting for age, race, gender, tobacco use, diabetes mellitus, hypertension, and hyperlipidemia.

RESULTS

NSTEMI was present in 3.2% of pneumonia patients versus 1.8% in the non-pneumonia population over 10-year period. For example, the 2005 database: [odds ratio (OR), 1.77; 95% confidence interval (CI), 1.73-1.80; P < 0.001]. For 2014, NSTEMI was present in 4.1% of pneumonia patients (PNA) versus 2.4% in the non-pneumonia population (OR, 1.72; 95% CI, 1.70-1.75; P < 0.001). NSTEMI remained independently associated with pneumonia following a multivariate analysis in 2005 (OR, 1.477; 95% CI, 1.447-1.508; P < 0.001) with a similar value in 2014 (OR, 1.445; 95% CI, 1.421-1.469; P < 0.001).

CONCLUSIONS

Using a large inpatient database, we found that NSTEMI was strongly associated with PNA versus non-pneumonia population over a 10-year period. Suggesting acute inflammatory cytokines or hypoxia which occurs during lung infection may play a role in NSTEMI development, reinforcing the importance of acute cardiac monitoring in patients with PNA.

Guideline-Concordant Antibiotic Therapy for the Hospital Treatment of Community-Acquired Pneumonia and 1-Year All-Cause and Cardiovascular Mortality in Older Adult Patients Surviving to Discharge

BACKGROUND

Selection of empiric antibiotic treatment for community-acquired pneumonia (CAP) that is concordant with clinical practice guidelines has been associated with improved short-term outcomes of this infection, but whether it is also associated with longer-term outcomes is unknown.

RESEARCH QUESTION

Is guideline-concordance of the initial antibiotic treatment given to older adult patients hospitalized with CAP associated with the 1-year all-cause and cardiovascular mortality risk of those patients who survive hospitalization for this infection?

STUDY DESIGN AND METHODS

A total of 1,909 older (> 65 years of age) patients were identified who survived hospitalization for CAP at The Ottawa Hospital (Ontario, Canada) between 2004 and 2015. Linking patients' information to hospital and provincial data sets, this study analyzed whether the selection of the initial antibiotic therapy for their CAP was concordant with current clinical practice guidelines, and whether guideline-concordance was associated with 1-year all-cause and cardiovascular mortality following their index CAP hospitalization. Adjustments were made for the patients' overall 1-year expected death risk; CAP severity; and history of previous pneumonia admissions, myocardial infarction, heart failure, or cerebrovascular disease.

RESULTS

Selection of guideline-concordant antibiotic therapy was associated with a trend towards lower all-cause mortality at 1 year post-CAP (hazard ratio, 0.82; 95% CI, 0.65-1.04; P = .099). Furthermore, the use of guideline-concordant antibiotic therapy was associated with a significant almost 50% reduction in cardiovascular death risk 1 year following CAP admission (hazard ratio, 0.53; 95% CI, 0.34-0.80; P = .003).

INTERPRETATION

Use of guideline-concordant antibiotic therapy for CAP treatment in older hospitalized patients is associated with a significant reduction in the risk of cardiovascular death at 1 year post-CAP. This finding further supports current clinical practice guideline recommendations for CAP treatment.

Impact of macrolide treatment on long-term mortality in patients admitted to the ICU due to CAP: a targeted maximum likelihood estimation and survival analysis

INTRODUCTION

Patients with community-acquired pneumonia (CAP) admitted to the intensive care unit (ICU) have high mortality rates during the acute infection and up to ten years thereafter. Recommendations from international CAP guidelines include macrolide-based treatment. However, there is no data on the long-term outcomes of this recommendation. Therefore, we aimed to determine the impact of macrolide-based therapy on long-term mortality in this population.

METHODS

Registered patients in the MIMIC-IV database 16 years or older and admitted to the ICU due to CAP were included. Multivariate analysis, targeted maximum likelihood estimation (TMLE) to simulate a randomised controlled trial, and survival analyses were conducted to test the effect of macrolide-based treatment on mortality six-month (6 m) and twelve-month (12 m) after hospital admission. A sensitivity analysis was performed excluding patients with Pseudomonas aeruginosa or MRSA pneumonia to control for Healthcare-Associated Pneumonia (HCAP).

RESULTS

3775 patients were included, and 1154 were treated with a macrolide-based treatment. The non-macrolide-based group had worse long-term clinical outcomes, represented by 6 m [31.5 (363/1154) vs 39.5 (1035/2621), p < 0.001] and 12 m mortality [39.0 (450/1154) vs 45.7 (1198/2621), p < 0.001]. The main risk factors associated with long-term mortality were Charlson comorbidity index, SAPS II, septic shock, and respiratory failure. Macrolide-based treatment reduced the risk of dying at 6 m [HR (95% CI) 0.69 (0.60, 0.78), p < 0.001] and 12 m [0.72 (0.64, 0.81), p < 0.001]. After TMLE, the protective effect continued with an additive effect estimate of - 0.069.

CONCLUSION

Macrolide-based treatment reduced the hazard risk of long-term mortality by almost one-third. This effect remains after simulating an RCT with TMLE and the sensitivity analysis for the HCAP classification.

Severe Infection and Risk of Cardiovascular Disease: A Multicohort Study

BACKGROUND

The excess risk of cardiovascular disease associated with a wide array of infectious diseases is unknown. We quantified the short- and long-term risk of major cardiovascular events in people with severe infection and estimated the population-attributable fraction.

METHODS

We analyzed data from 331 683 UK Biobank participants without cardiovascular disease at baseline (2006-2010) and replicated our main findings in an independent population from 3 prospective cohort studies comprising 271 329 community-dwelling participants from Finland (baseline 1986-2005). Cardiovascular risk factors were measured at baseline. We diagnosed infectious diseases (the exposure) and incident major cardiovascular events after infections, defined as myocardial infarction, cardiac death, or fatal or nonfatal stroke (the outcome) from linkage of participants to hospital and death registers. We computed adjusted hazard ratios (HRs) and 95% CIs for infectious diseases as short- and long-term risk factors for incident major cardiovascular events. We also calculated population-attributable fractions for long-term risk.

RESULTS

In the UK Biobank (mean follow-up, 11.6 years), 54 434 participants were hospitalized for an infection, and 11 649 had an incident major cardiovascular event at follow-up. Relative to participants with no record of infectious disease, those who were hospitalized experienced increased risk of major cardiovascular events, largely irrespective of the type of infection. This association was strongest during the first month after infection (HR, 7.87 [95% CI, 6.36-9.73]), but remained elevated during the entire follow-up (HR, 1.47 [95% CI, 1.40-1.54]). The findings were similar in the replication cohort (HR, 7.64 [95% CI, 5.82-10.03] during the first month; HR, 1.41 [95% CI, 1.34-1.48] during mean follow-up of 19.2 years). After controlling for traditional cardiovascular risk factors, the population-attributable fraction for severe infections and major cardiovascular events was 4.4% in the UK Biobank and 6.1% in the replication cohort.

CONCLUSIONS

Infections severe enough to require hospital treatment were associated with increased risks for major cardiovascular disease events immediately after hospitalization. A small excess risk was also observed in the long-term, but residual confounding cannot be excluded.

Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio are Important Indicators for Predicting in-Hospital Death in Elderly AMI Patients

Aim

To investigate the role of neutrophil-to-lymphocyte ratio(NLR) and platelet-to-lymphocyte(PLR) in predicting the risk of in-hospital mortality in elderly acute myocardial infarction(AMI) patients.

Methods

This study was a single-center, retrospective and observational study. From December 2015 to December 2021, a total of 1550 elderly patients (age ≥ 60 years) with AMI with complete clinical history data were enrolled in the Second Hospital of Dalian Medical University. Routine blood tests were performed on admission, and NLR and PLR were calculated based on neutrophil, platelet, and lymphocyte counts. Outcome was defined as all-cause mortality during hospitalization. Cox regression and restricted spline cubic(RCS) models were used to evaluate the association of NLR and in-hospital mortality risk and the association of PLR with in-hospital mortality risk, respectively.

Results

(1) A total of 132 (8.5%) patients died during hospitalization. From the results of blood routine, the white blood cell, neutrophil, NLR and PLR in the death group were higher than those in the non-death group, while the lymphocyte was lower than that in the non-death group, and the difference was statistically significant (P < 0.05). (2) The results of receiver operating characteristic(ROC) curves analysis showed that the predictive ability of NLR (AUC = 0.790) for in-hospital death was better than that of PLR (AUC = 0.637). (3) Multivariate Cox proportional regression hazard models showed that high NLR was associated with the risk of in-hospital mortality in elderly AMI patients (HR = 3.091, 95% CI 2.097-4.557, P < 0.001), while high PLR was not. (4) RCS models showed a nonlinear dose-response relationship between NLR and in-hospital death (P for nonlinear = 0.0007).

Conclusion

High NLR (> 6.69) is associated with the risk of in-hospital mortality in elderly patients with AMI and can be an independent predictor of poor short-term prognosis in elderly patients with AMI.

BNT162b2 or CoronaVac Vaccinations Are Associated With a Lower Risk of Myocardial Infarction and Stroke After SARS-CoV-2 Infection Among Patients With Cardiovascular Disease

Background COVID-19 vaccines have demonstrated effectiveness against SARS-CoV-2 infection, hospitalization, and mortality. The association between vaccination and risk of cardiovascular complications shortly after SARS-CoV-2 infection among patients with cardiovascular disease remains unknown. Methods and Results A case-control study was conducted with cases defined as patients who had myocardial infarction or stroke within 28 days after SARS-CoV-2 infection between January 1, 2022 and August 15, 2022. Controls were defined as all other patients who attended any health services and were not cases. Individuals without history of cardiovascular disease were excluded. Each case was randomly matched with 10 controls according to sex, age, Charlson comorbidity index, and date of hospital admission. Adjusted odds ratio with 95% CI was estimated using conditional logistic regression. We identified 808 cases matched with 7771 controls among all patients with cardiovascular disease. Results showed that vaccination with BNT162b2 or CoronaVac was associated with a lower risk of myocardial infarction or stroke after SARS-CoV-2 infection with a dose-response relationship. For BNT162b2, risk decreased from 0.49 (95% CI, 0.29-0.84) to 0.30 (95% CI, 0.20-0.44) and 0.17 (95% CI, 0.08-0.34) from 1 to 3 doses, respectively. Similar trends were observed for CoronaVac, with risk decreased from 0.69 (95% CI, 0.57-0.85) to 0.42 (95% CI, 0.34-0.52) and 0.32 (95% CI, 0.21-0.49) from 1 to 3 doses, respectively. Conclusions Vaccination with BNT162b2 or CoronaVac is associated with a lower risk of myocardial infarction or stroke after SARS-CoV-2 infection among patients with cardiovascular disease.

Risk Factors for Major Cardiovascular Events in Adult Sepsis Survivors: A Population-Based Cohort Study

OBJECTIVES

To describe risk factors for major cardiovascular events in adults following hospital discharge after sepsis.

DESIGN

Population-based cohort study.

SETTING

Ontario, Canada (2008-2017).

PATIENTS

Adult patients (age 18 yr or older) who survived a first sepsis hospitalization without preexisting cardiovascular disease.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary composite outcome was myocardial infarction, stroke, or cardiovascular death up to 5 years following hospital discharge. We used cause-specific Cox proportional hazards models that accounted for the competing risk of noncardiovascular death to describe factors associated with major cardiovascular events. We identified 268,259 adult patients without cardiovascular disease (median age, 72 yr), of whom 10.4% experienced a major cardiovascular event during a median follow-up of 3 years. After multivariable adjustment, age (hazard ratio [HR], 1.53 for every 10 yr; 95% CI, 1.51-1.54), male sex (HR, 1.23; 95% CI, 1.20-1.26), diabetes mellitus (HR, 1.24; 95% CI, 1.21-1.27), hypertension (HR, 1.34; 95% CI, 1.30-1.38), prevalent atrial fibrillation (HR, 1.46; 95% CI, 1.40-1.52), and chronic kidney disease (HR, 1.11; 95% CI, 1.06-1.16) were associated with major cardiovascular events during long-term follow-up. Sepsis characteristics such as site of infection (pneumonia vs other: HR, 1.09; 95% CI, 1.05-1.12), septic shock (HR, 1.08; 95% CI, 1.05-1.11), and renal replacement therapy (HR, 1.51; 95% CI, 1.38-1.64) were also associated with subsequent cardiovascular events. In an analysis restricting to patients with troponin values measured during the hospitalization (26,400 patients), an elevated troponin was also associated with subsequent cardiovascular events (HR, 1.23; 95% CI, 1.13-1.33).

CONCLUSIONS

Classic cardiovascular risk factors, comorbid conditions, and characteristics of the sepsis episode were associated with a higher hazard of major cardiovascular events in adult sepsis survivors. These findings may inform enrichment strategies for future studies.

Awareness and Knowledge of Pneumococcal Vaccination in Cardiology Outpatient Clinics and the Impact of Physicians’ Recommendations on Vaccination Rates

Aim: We aimed to evaluate the awareness of pneumococcal vaccination (PCV13, PPSV23) in general cardiology outpatient clinics and impact of physicians’ recommendations on vaccination rates. Methods: This was a multicenter, observational, prospective cohort study. Patients over the age of 18 from 40 hospitals in different regions of Turkey who applied to the cardiology outpatient clinic between September 2022 and August 2021 participated. The vaccination rates were calculated within three months of follow-up from the admitting of the patient to cardiology clinics. Results: The 403 (18.2%) patients with previous pneumococcal vaccination were excluded from the study. The mean age of study population (n = 1808) was 61.9 ± 12.1 years and 55.4% were male. The 58.7% had coronary artery disease, hypertension (74.1%) was the most common risk factor, and 32.7% of the patients had never been vaccinated although they had information about vaccination before. The main differences between vaccinated and unvaccinated patients were related to education level and ejection fraction. The physicians’ recommendations were positively correlated with vaccination intention and behavior in our participants. Multivariate logistic regression analysis showed a significant correlation between vaccination and female sex [OR = 1.55 (95% CI = 1.25–1.92), p < 0.001], higher education level [OR = 1.49 (95% CI = 1.15–1.92), p = 0.002] patients’ knowledge [OR = 1.93 (95% CI = 1.56–2.40), p < 0.001], and their physician’s recommendation [OR = 5.12 (95% CI = 1.92–13.68), p = 0.001]. Conclusion: To increase adult immunization rates, especially among those with or at risk of cardiovascular disease (CVD), it is essential to understand each of these factors. Even if during COVID-19 pandemic, there is an increased awareness about vaccination, the vaccine acceptance level is not enough, still. Further studies and interventions are needed to improve public vaccination rates.

Transient increase in atherosclerotic plaque macrophage content following Streptococcus pneumoniae pneumonia in ApoE-deficient mice

Introduction

Despite epidemiological associations between community acquired pneumonia (CAP) and myocardial infarction, mechanisms that modify cardiovascular disease during CAP are not well defined. In particular, largely due to a lack of relevant experimental models, the effect of pneumonia on atherosclerotic plaques is unclear. We describe the development of a murine model of the commonest cause of CAP, Streptococcus pneumoniae pneumonia, on a background of established atherosclerosis. We go on to use our model to investigate the effects of pneumococcal pneumonia on atherosclerosis.

Methods

C57BL/6J and ApoE-/- mice were fed a high fat diet to promote atherosclerotic plaque formation. Mice were then infected with a range of S. pneumoniae serotypes (1, 4 or 14) with the aim of establishing a model to study atherosclerotic plaque evolution after pneumonia and bacteremia. Laser capture microdissection of plaque macrophages enabled transcriptomic analysis.

Results

Intratracheal instillation of S. pneumoniae in mice fed a cholate containing diet resulted in low survival rates following infection, suggestive of increased susceptibility to severe infection. Optimization steps resulted in a final model of male ApoE-/- mice fed a Western diet then infected by intranasal instillation of serotype 4 (TIGR4) S. pneumoniae followed by antibiotic administration. This protocol resulted in high rates of bacteremia (88.9%) and survival (88.5%). Pneumonia resulted in increased aortic sinus plaque macrophage content 2 weeks post pneumonia but not at 8 weeks, and no difference in plaque burden or other plaque vulnerability markers were found at either time point. Microarray and qPCR analysis of plaque macrophages identified downregulation of two E3 ubiquitin ligases, Huwe1 and Itch, following pneumonia. Treatment with atorvastatin failed to alter plaque macrophage content or other plaque features.

Discussion

Without antibiotics, ApoE-/- mice fed a high fat diet were highly susceptible to mortality following S. pneumoniae infection. The major infection associated change in plaque morphology was an early increase in plaque macrophages. Our results also hint at a role for the ubiquitin proteasome system in the response to pneumococcal infection in the plaque microenvironment.