Pneumonia, thrombosis and vascular disease

Cardiac SARS-CoV-2 Infection, Involvement of Cytokines in Postmortem Immunohistochemical Study

In the context of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, significant attention was given to pulmonary manifestations. However, cardiac involvement is increasingly recognized as a critical factor influencing the prognosis, leading to myocardial damage, heart failure, acute coronary syndromes, potentially lethal arrhythmic events, and sudden cardiac death. Despite these findings, there is a lack of studies detailing the necroscopic, macroscopic, and microscopic cardiac changes associated with SARS-CoV-2. This study aimed to investigate the presence of SARS-CoV-2 viral proteins in cardiac tissue using immunohistochemical techniques to assess viral tropism. The analysis of cardiac tissue samples from deceased subjects, in different stages of conservation, confirmed to be positive for SARS-CoV-2 via reverse transcriptase-polymerase chain reaction (RT-PCR), showed immunopositivity for the SARS-CoV-2-NP viral antigen in 33% of cases. Notably, the presence of leukocyte infiltrates sufficient for diagnosing lymphocytic myocarditis was not observed. The central proinflammatory cytokines involved in the pathogenetic mechanism of coronavirus disease 19 (COVID-19) were researched using the immunohistochemical method. A significant increase in cytokine expression was detected, indicating myocardial involvement and dysfunction during SARS-CoV-2 infection. These findings suggest that the immunohistochemical detection of SARS-CoV-2 viral antigens and inflammatory cytokine expression in cardiac tissue could be crucial for a proper forensic assessment of the cause of death, even in sudden cardiac death.

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.

Immune regulation of the gut-brain axis and lung-brain axis involved in ischemic stroke

Local ischemia often causes a series of inflammatory reactions when both brain immune cells and the peripheral immune response are activated. In the human body, the gut and lung are regarded as the key reactional targets that are initiated by brain ischemic attacks. Mucosal microorganisms play an important role in immune regulation and metabolism and affect blood-brain barrier permeability. In addition to the relationship between peripheral organs and central areas and the intestine and lung also interact among each other. Here, we review the molecular and cellular immune mechanisms involved in the pathways of inflammation across the gut-brain axis and lung-brain axis. We found that abnormal intestinal flora, the intestinal microenvironment, lung infection, chronic diseases, and mechanical ventilation can worsen the outcome of ischemic stroke. This review also introduces the influence of the brain on the gut and lungs after stroke, highlighting the bidirectional feedback effect among the gut, lungs, and brain.

Development and validation of a risk model for intracardiac thrombosis in patients with dilated cardiomyopathy: a retrospective study

Intracardiac thrombosis is a severe complication in patients with non-ischemic dilated cardiomyopathy. This study aims to develop and validate an individualized nomogram to evaluate the risk of intracardiac thrombosis in patients with non-ischemic dilated cardiomyopathy. This retrospective study included patients diagnosed with dilated cardiomyopathy at first admission. Clinical baseline characteristics were acquired from electronic medical record systems. Multiple methods were applied to screen the key variables and generate multiple different variable combinations. Multivariable logistic regression was used to build the models, and the optimal model was chosen by comparing the discrimination. Then we checked the performance of the model in different thrombus subgroups. Finally, the model was presented using a nomogram and evaluated from the perspectives of discrimination, calibration, and clinical usefulness. Internal validation was performed by extracting different proportions of data for Bootstrapping. Ultimately, 564 eligible patients were enrolled, 67 of whom developed an intracardiac thrombosis. Risk factors included d-dimer, white blood cell count, high-sensitivity C-reactive protein, pulse pressure, history of stroke, hematocrit, and NT-proBNP in the optimal model. The model had good discrimination and calibration, and the area under the curve (AUC) was 0.833 (0.782-0.884), and the model's performance in each subgroup was stable. Clinical decision curve analysis showed that the model had clinical application value when the high-risk threshold was between 2% and 78%. The AUC of interval validation (30% and 70% data resampling) was 0.844 (0.765-0.924) and 0.833 (0.775-0.891), respectively. This novel intracardiac thrombosis nomogram could be conveniently applied to facilitate the individual intracardiac thrombosis risk assessment in patients with non-ischemic dilated cardiomyopathy.

Predicting adverse outcomes in adults with a community-acquired lower respiratory tract infection: a protocol for the development and validation of two prediction models for (i) all-cause hospitalisation and mortality and (ii) cardiovascular outcomes

BACKGROUND

Community-acquired lower respiratory tract infections (LRTI) are common in primary care and patients at particular risk of adverse outcomes, e.g., hospitalisation and mortality, are challenging to identify. LRTIs are also linked to an increased incidence of cardiovascular diseases (CVD) following the initial infection, whereas concurrent CVD might negatively impact overall prognosis in LRTI patients. Accurate risk prediction of adverse outcomes in LRTI patients, while considering the interplay with CVD, can aid general practitioners (GP) in the clinical decision-making process, and may allow for early detection of deterioration. This paper therefore presents the design of the development and external validation of two models for predicting individual risk of all-cause hospitalisation or mortality (model 1) and short-term incidence of CVD (model 2) in adults presenting to primary care with LRTI.

METHODS

Both models will be developed using linked routine electronic health records (EHR) data from Dutch primary and secondary care, and the mortality registry. Adults aged ≥ 40 years with a GP-diagnosis of LRTI between 2016 and 2019 are eligible for inclusion. Relevant patient demographics, medical history, medication use, presenting signs and symptoms, and vital and laboratory measurements will be considered as candidate predictors. Outcomes of interest include 30-day all-cause hospitalisation or mortality (model 1) and 90-day CVD (model 2). Multivariable elastic net regression techniques will be used for model development. During the modelling process, the incremental predictive value of CVD for hospitalisation or all-cause mortality (model 1) will also be assessed. The models will be validated through internal-external cross-validation and external validation in an equivalent cohort of primary care LRTI patients.

DISCUSSION

Implementation of currently available prediction models for primary care LRTI patients is hampered by limited assessment of model performance. While considering the role of CVD in LRTI prognosis, we aim to develop and externally validate two models that predict clinically relevant outcomes to aid GPs in clinical decision-making. Challenges that we anticipate include the possibility of low event rates and common problems related to the use of EHR data, such as candidate predictor measurement and missingness, how best to retrieve information from free text fields, and potential misclassification of outcome events.

Risk of post-fracture pneumonia and its association with cardiovascular events and mortality in adults with intellectual disabilities

Objective

Fragility fractures are associated with an increased risk of pneumonia, which is a leading cause of death in adults with intellectual disabilities; however, the timing and complications of post-fracture pneumonia are underinvestigated. The objectives of this study were to determine the 30-day pneumonia rate post-fracture and the association of post-fracture pneumonia with mortality and cardiovascular events among adults with intellectual disabilities.

Methods

This retrospective cohort study was conducted using Medicare and commercial claims from 01 January 2011 to 31 December 2016. Incidence of pneumonia 30 days after a fragility fracture among adults ≥18 years old with intellectual disabilities (Fx cohort) was compared to the incidence among matched adults with intellectual disabilities without fractures (w/oFx cohort) and the general population of patients with an incident fragility fracture (GP+Fx). For the Fx cohort, Cox regression was used to examine the adjusted association of time-varying pneumonia (within 30 days post-fracture) with mortality and incidence of cardiovascular events 0-30, 31-365, and 366-730 days post-fracture.

Results

There was a high-early rate of pneumonia within 30 days post-fracture for young, middle-aged, and elderly adults with intellectual disabilities (n = 6,183); this rate was 2.2- to 6.1-fold higher than the rate among the w/oFx (n = 12,366) and GP+Fx (n = 363,995) cohorts (all P < 0.05). For the Fx cohort, post-fracture 30-day incidence of pneumonia was associated with an increased 30-day rate of mortality (adjusted HR [aHR] = 5.19; 95% confidence interval [CI] = 3.68-7.32), heart failure (aHR = 2.96; 95% CI = 1.92-4.56), and cerebrovascular disease (aHF = 1.48; 95% CI = 0.93-2.35; P = 0.098), with sustained effects to 1 year for heart failure (aHR = 1.61; 95% CI = 1.19-2.17) and 2 years for mortality (aHR = 1.39; 95% CI = 1.06-1.83), and without evidence of effect modification by age.

Discussion

Adults with intellectual disabilities are vulnerable to post-fracture pneumonia within 30 days, and complications arising from this, across the adult lifespan, and not only during the elderly years.

Pneumonia-Induced Inflammation, Resolution and Cardiovascular Disease: Causes, Consequences and Clinical Opportunities

Pneumonia is inflammation in the lungs, which is usually caused by an infection. The symptoms of pneumonia can vary from mild to life-threatening, where severe illness is often observed in vulnerable populations like children, older adults, and those with preexisting health conditions. Vaccines have greatly reduced the burden of some of the most common causes of pneumonia, and the use of antimicrobials has greatly improved the survival to this infection. However, pneumonia survivors do not return to their preinfection health trajectories but instead experience an accelerated health decline with an increased risk of cardiovascular disease. The mechanisms of this association are not well understood, but a persistent dysregulated inflammatory response post-pneumonia appears to play a central role. It is proposed that the inflammatory response during pneumonia is left unregulated and exacerbates atherosclerotic vascular disease, which ultimately leads to adverse cardiac events such as myocardial infarction. For this reason, there is a need to better understand the inflammatory cross talk between the lungs and the heart during and after pneumonia to develop therapeutics that focus on preventing pneumonia-associated cardiovascular events. This review will provide an overview of the known mechanisms of inflammation triggered during pneumonia and their relevance to the increased cardiovascular risk that follows this infection. We will also discuss opportunities for new clinical approaches leveraging strategies to promote inflammatory resolution pathways as a novel therapeutic target to reduce the risk of cardiac events post-pneumonia.

Association between PaO2/FiO2 ratio and thrombotic events in COVID-19 patients

PaO₂/FiO₂ (P/F ratio) is considered a marker of hypoxia/hypoxemia and mortality. Several prothrombotic changes are associated with the decrease of P/F ratio. The role of P/F ratio in patients with arterial and venous thrombosis remains unclear. The aim of this study was to assess in patients with coronavirus disease 2019 (COVID-19), the association between P/F ratio and arterial/venous thrombosis. One thousand and four hundred and six COVID-19 patients were recruited; 289 (21%) patients had P/F ratio < 200 and 1117 (79%) ≥ 200. Compared to the patients with P/F ratio ≥ 200, those with P/F ratio < 200 were older and with higher levels of glycemia, D-dimer and lower levels of albumin. Multiple linear regression analysis showed that albumin (standardized coefficient β:  0.156; SE: 0.001; p = 0.0001) and D-dimer (standardized coefficient β: -0.135; SE: 0.0001; p = 0.0001) were associated with P/F ratio. During the hospitalization 159 patients were transferred in intensive care unit (ICU), 253 patients died, 156 patients had arterial or venous thrombotic events. A bivariate logistic analysis was performed to analyze the predictors of thrombosis in COVID-19 patients; P/F ratio < 200 (Odds Ratio: [OR] 1.718, 95% Confidence Interval [CI] 1.085-2.718, p = 0.021), albumin (OR 1.693, 95% CI 1.055-2.716, p = 0.029), D-dimer (OR 3.469, 95% CI 2.110-5.703, p < 0.0001), coronary artery disease (CAD) (OR 1.800, 95% CI 1.086-2.984, p = 0.023) and heart failure (OR 2.410 95% CI 1.385-4.193, p = 0.002) independently predicted thrombotic events in this population. This study suggests that the P/F ratio is associated with thrombotic events by promoting a hypercoagulation state in patients hospitalized for COVID-19.

Disseminated Intravascular Coagulation in Sepsis and Associated Factors

Background: sepsis is a life-threatening organ dysfunction caused by an excessive host immunological response to infection. The incidence of sepsis is increasing every year, and sepsis is the primary cause of mortality in intensive care units (ICUs). DIC is a coagulopathy syndrome that causes microvascular and macrovascular thrombosis and increases the risk of bleeding due to consumptive coagulopathy. The pathophysiology of DIC in sepsis is complex, and further research is required to investigate the involved mechanisms and risk factors. Method: this study is a prognostic analysis of a retrospective cohort. Samples were patients diagnosed with sepsis and admitted to Cipto Mangunkusumo National General Hospital from January 2016 to October 2022. Research subjects were followed until occurrence of DIC during sepsis or recovery from sepsis. The research subjects were selected from medical records using a consecutive total sampling approach. The inclusion criteria were patients aged ≥18 years old and diagnosed with sepsis according to qSOFA criteria with a score of 2. The exclusion criterion was an incomplete medical record. Bivariate and multivariate logistic regression analyses were performed to determine which independent variables contributed to the incidence of DIC and obtain the odds ratios (ORs). p < 0.05 was considered to indicate a statistically significant difference. Results: a total of 248 patients were included after considering the inclusion and exclusion criteria. Of these, 50 (20.2%) septic patients developed DIC. In the multivariate analysis, albumin ≤2.5 g/dL (OR: 2.363; 95% CI: 1.201−4.649), respiratory infection (OR: 2.414; 95% CI: 1.046−5.571), and antibiotic treatment ≥1 h (OR: 2.181; 95% CI: 1.014−4.689) were associated with DIC development. On the basis of the ROC curve, the area under the curve (AUC) was determined to be 0.705 with 95% CI = (0.631−0.778). Conclusion: in our study, the prevalence of DIC in septic patients was 20.2%. Low albumin, respiratory infection, and antibiotic treatment ≥1 h were found to be risk factors for development of DIC in septic patients.

Thromboembolic events in deceased patients with proven SARS-CoV-2 infection: Frequency, characteristics and risk factors

BACKGROUND

Infection with the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) results in respiratory syndromes but also in vascular complications such as thromboembolism (TE). In this regard, immunothrombosis, resulting from inflammation in SARS-CoV-2 infected tissues, has been described. Data on TE in COVID-19 are mainly based on clinical observational and/or incomplete autopsy studies. The true burden of TE and the relevance of genetic predisposition, however, have not been resolved.

OBJECTIVES

Here, we report on a consecutive cohort of 100 fully autopsied patients deceased by SARS-CoV-2 infections during the first wave of the pandemic (March to April 2020). We investigated the localization of TE, potential clinical risk factors, and the prothrombotic gene mutations, factor V Leiden and prothrombin G20210A, in postmortem blood or tissue samples.

RESULTS

TE was found in 43/100 autopsies. 93 % of TE events were venous occlusions, with 23 patients having pulmonary thromboembolism (PT) with or without lower-extremity deep vein thrombosis. Of these, 70 % showed PT restricted to (sub)segmental arteries, consistent with in situ immunothrombosis. Patients with TE had a significantly higher BMI and died more frequently at an intensive care unit. Hereditary thrombophilia factors were not associated with TE.

CONCLUSIONS

Our autopsy results show that a significant proportion of SARS-CoV-2 infected patients suffer from TE, affecting predominantly the venous system. Orthotopic peripheral PT was the most frequent finding. Hereditary thrombophilia appears not to be a determinant for TE in COVID-19. However, obesity and the need for intensive care increase the risk of TE in these patients.

Development and Validation of a Risk Assessment Model for Venous Thromboembolism in Patients With Invasive Mechanical Ventilation

Background

Patients with invasive mechanical ventilation may be at high risk of acquiring venous thromboembolism (VTE). We aim to develop risk assessment models for predicting the improvement of VTE in invasively ventilated patients.

Methodology

A total of 6,734 invasively ventilated patients enrolled from the Medical Information Mart for Intensive Care-III (MIMIC-III) database were used as input for model development and internal validation, while data from 168 patients from Nanfang Hospital were used for external validation. Logistic regression was performed based on predictive factors derived from least absolute shrinkage and selection operator (LASSO) regression analysis and logistic regression with backward selection to develop two Risk Assessment Models (RAM), namely, I and II, for the prediction of VTE, respectively. Model selection was performed by evaluation of the area under the receiver operating characteristic curve (AUC), the goodness of fit with calibration curves, and decision curve analyses (DCA).

Results

RAM-I included prior history of VTE, in-hospital immobilization, infection, glucose, the use of antiplatelet, and activated partial thromboplastin time (APTT) as variables, while RAM-II included prior history of VTE, in-hospital immobilization, infection, ischemic stroke, glucose, the use of antiplatelet and APTT as variables. Compared with RAM-I and ICU-Venous Thromboembolism Score, RAM-II exhibited better discrimination in the training dataset (AUC = 0.826), internal validation dataset (AUC = 0.771), and external validation dataset (AUC = 0.770). Additionally, DCA demonstrated that RAM-II was clinically beneficial. Inspection of the calibration curves revealed good agreement between the predictions and observations.

Conclusions

A RAM for VTE in invasively ventilated patients was developed with reasonable performance.

Questions about COVID-19 associated coagulopathy: possible answers from the viscoelastic tests

Abnormal coagulation parameters are often observed in patients with coronavirus disease 2019 (COVID-19) and the severity of derangement has been associated with a poor prognosis. The COVID-19 associated coagulopathy (CAC) displays unique features that include a high risk of developing thromboembolic complications. Viscoelastic tests (VETs), such as thromboelastometry (ROTEM), thromboelastography (TEG) and Quantra Hemostasis Analyzer (Quantra), provide "dynamic" data on clot formation and dissolution; they are used in different critical care settings, both in hemorrhagic and in thrombotic conditions. In patients with severe COVID-19 infection VETs can supply to clinicians more information about the CAC, identifying the presence of hypercoagulable and hypofibrinolysis states. In the last year, many studies have proposed to explain the underlying characteristics of CAC; however, there remain many unanswered questions. We tried to address some of the important queries about CAC through VETs analysis.

Platelets mediate inflammatory monocyte activation by SARS-CoV-2 Spike protein

Infection with SARS-CoV-2, the causative agent of COVID-19, causes mild to moderate disease in most patients but carries a risk of morbidity and mortality. Seriously affected individuals manifest disorders of hemostasis and a cytokine storm, but it is not understood how these manifestations of severe COVID-19 are linked. Here, we showed that the SARS-CoV-2 spike protein engaged the CD42b receptor to activate platelets via 2 distinct signaling pathways and promoted platelet-monocyte communication through the engagement of P selectin/PGSL-1 and CD40L/CD40, which led to proinflammatory cytokine production by monocytes. These results explain why hypercoagulation, monocyte activation, and a cytokine storm are correlated in patients severely affected by COVID-19 and suggest a potential target for therapeutic intervention.

Ischemic Stroke and Asymptomatic Pulmonary Opacities

PURPOSE

Pulmonary opacities are described in many chest radiograph reports in stroke patients and are often asymptomatic. The aim of this study is to investigate the clinical features associated with asymptomatic pulmonary opacities (APO) and evaluate APO prognostic value in ischemic stroke.

METHODS

We prospectively analyzed patients with acute ischemic stroke without pneumonia symptoms referred to our stroke center. All patients underwent a chest x-ray within 48 hours after admission. We divided patients with APO (defined as asymptomatic area of increased pulmonary attenuation) and patients without APO. Firstly, we compared clinical, laboratory, and echocardiographic parameters between groups; secondly, APO were evaluated as a possible predictor of the neurological severity at discharge and functional outcome at 90 days.

RESULTS

We included 162 patients, 78 of whom had APO. On univariate analysis, we observed a significant difference between patients with APO and patients without APO in terms of neutrophils (73,56±10,10 vs 69,72±12,29; p=0,031), atrial fibrillation (AF, paroxysmal 27,4% vs 25,6%; permanent 19% vs 2,6%; p<0,002), cardioembolic etiology (37,2% vs 22,7%, p <0,033), thrombectomy (58,3% vs 42,9%, p <0,05), dysphagia/vomit (34,5% vs 14,10%, p<0,005), admission NIHSS (14,20±5,98 vs 10,29±5,82, p=0,001), discharge NIHSS (8,68±6,73 vs 5,64±6,20; p=0,003), and 90 days mRS (3,47±2,12 vs 2,31±1,93; p=0,001). On multivariate analysis, APO were significantly associated with admission NIHSS and AF. APO were a predictor of outcome on univariate analysis, but not on multivariate.

CONCLUSION

APO in acute ischemic stroke are associated with AF. APO were not a predictor of neurological and functional outcome.

Thrombosis in Covid-19 and non-Covid-19 pneumonia: role of platelets

Platelets may be a target of bacteria and viruses, which can directly or indirectly activate them so promoting thrombosis. In accordance with this, community-acquired pneumonia (CAP) is complicated by ischemia-related vascular disease (myocardial infarction and stroke) in roughly 10% of patients while the incidence of venous thrombosis is uncertain. In CAP platelet biosynthesis of TxA2 is augmented and associated with myocardial infarction; however, a cause-effect relationship is still unclear as unclear is if platelet activation promotes thrombosis or functional changes of coronary tree such vasospasm. Retrospective studies suggested a potential role of aspirin in reducing mortality but the impact on vascular disease is still unknown. Coronavirus disease 2019 (Covid-19) is complicated by thrombosis in roughly 20% of patients with an almost equivalent localization in arterial and venous circulation. Platelet activation seems to have a pivot role in the thrombotic process in Covid-19 as consistently evidenced by its involvement in promoting Tissue Factor up-regulation via leucocyte interaction. Until now, antiplatelet treatment has been scarcely considered for the treatment of Covid-19; interventional trials, however, are in progress to explore this issue. The aim of this review is 1) to compare the type of vascular diseases complicating CAP and Covid-19 2) to assess the different role of platelets in both diseases and 3) to discuss if antiplatelet treatment is potentially useful to improve clinical outcomes.

Acute Lower Respiratory Tract Infection Increased the Risk of Cardiovascular Events and All-Cause Mortality in Elderly Patients With Stable Coronary Artery Disease

Objective: To investigate the predictors of acute cardiovascular events within 90 days after an acute lower respiratory tract infection (ALRTI) in elderly patients with stable coronary artery disease (sCAD). Methods: Observational analyses were conducted in a prospective cohort of the elderly with sCAD, during 90 days after they were hospitalized for ALRTI. Multiple logistic regression analysis was performed to identify predictors for acute cardiovascular events and all-cause mortality. Results: The present study comprised 426 patients with sCAD (median age: 88 years; IQR: 84-91; range: 72-102). Among these patients, 257 suffering from ALRTI were enrolled in the infection group. Meanwhile, 169 patients who did not suffer from ALRTI were regarded as the non-infection group. Compared with the non-infection group, patients in the infection group had a higher incidence of acute cardiovascular events (31.9 vs. 13.6%, p < 0.001) and all-cause mortality (13.2 vs. 1.8%, p < 0.001) during the 90-day follow-up. In addition, in the infection group, the incidence of cardiovascular events was also higher than those in the non-infection group during the 7-day and 30-day follow-up (10.9 vs. 2.4%, p = 0.001; 20.6 vs. 6.5%, p < 0.001). The same difference in the incidence of all-cause mortality during 7 and 30 days (1.2 vs. 0%, p = 0.028; 3.9 vs. 0.6%, p = 0.021) was observed between the two groups. Furthermore, multiple regression analysis found that ALRTI was independently associated with increased risk of cardiovascular events and all-cause mortality in elderly patients with sCAD. Conclusion: In elderly patients with sCAD, ALRTI was an independent predictor for both cardiovascular events and all-cause mortality.

The relationship between coronary artery disease and clinical outcomes in COVID-19: a single-center retrospective analysis

INTRODUCTION

Recent studies have reported evidence that coronavirus disease 2019 (COVID-19) has disproportionately affected patients with underlying comorbidities. Our study aims to evaluate the impact of both cardiac and noncardiac comorbidities on a high-risk population with COVID-19 infection and coronary artery disease (CAD) compared to those without CAD.

METHODS

This is a retrospective study of patients who tested COVID-19 positive via reverse transcriptase-PCR (RT-PCR) assay. We compared the characteristics and outcomes of patients with and without CAD. Population demographics, comorbidities and clinical outcomes were collected and analyzed. Multivariate logistic regression analysis was used to identify factors associated with inpatient mortality.

RESULTS

A final sample population of 355 patients was identified, 77 of which had a known diagnosis of coronary artery disease. Our study population had a higher proportion of females, and those with CAD were significantly older. The rates of cardiovascular risk factors including hypertension, diabetes mellitus and chronic kidney disease, as well as heart failure and chronic obstructive pulmonary disease were significantly higher in the CAD population. Lactate dehydrogenase was the only inflammatory marker significantly lower in the CAD group, while troponin and brain natriuretic peptide were significantly higher in this population. Patients with CAD also had significantly higher inpatient mortality (31% vs 20%, P = 0.046) and need for renal replacement therapy (33% vs 11%, P < 0.0001) compared to the non-CAD group. However, only age [odds ratio 1.041 (1.017-1.066), P = 0.001] was significantly associated with mortality in the overall population after adjusting for demographics and comorbidities, while the presence of CAD was not independently associated with mortality.

CONCLUSION

Patients with CAD and COVID-19 have higher rates of comorbidities, inpatient mortality and need for renal replacement therapy compared to their non-CAD counterparts. However, CAD in itself was not associated with mortality after adjusting for other covariates, suggesting that other factors may play a larger role in the increased mortality and poor outcomes in these patients.

Low-Grade Endotoxemia and Thrombosis in COVID-19

INTRODUCTION

Patients with community-acquired pneumonia display enhanced levels of lipopolysaccharides (LPS) compared with controls, suggesting that low-grade endotoxemia may be implicated in vascular disturbances. It is unknown whether this occurs in patients with coronavirus 2019 (COVID-19) and its impact on thrombotic complications.

METHODS

We measured serum levels of zonulin, a marker of gut permeability, LPS, and D-dimer in 81 patients with COVID-19 and 81 healthy subjects; the occurrence of thrombotic events in COVID-19 during the intrahospital stay was registered.

RESULTS

Serum LPS and zonulin were higher in patients with COVID-19 than in control subjects and, in COVID-19, significantly correlated (R = 0.513; P < 0.001). Among the 81 patients with COVID-19, 11 (14%) experienced thrombotic events in the arterial (n = 5) and venous circulation (n = 6) during a median follow-up of 18 days (interquartile range 11-27 days). A logistic regression analysis showed that LPS (P = 0.024) and D-dimer (P = 0.041) independently predicted thrombotic events.

DISCUSSION

The study reports that low-grade endotoxemia is detectable in patients with COVID-19 and is associated with thrombotic events. The coexistence of low-grade endotoxemia with enhanced levels of zonulin may suggest enhanced gut permeability as an underlying mechanism.

Corticosteroid use, myocardial injury and in-hospital cardiovascular events in patients with community-acquired pneumonia

BACKGROUND AND PURPOSE

Corticosteroids are often prescribed to community-acquired pneumonia (CAP) patients, but the relationship with major cardiovascular events (MACEs) is unclear.

EXPERIMENTAL APPROACH

541 CAP patients were recruited (334 males, mean age 71.9 ± 16.2 years). High-sensitivity troponin T (hs-cTnT) was measured at admission, during the hospital stay and at discharge. MACE occurrence was registered during a long-term follow-up.

KEY RESULTS

Overall, 318 patients (59%) showed hs-cTnT elevation >99th percentile (>0.014 μg/L). Age, heart failure and the increasing quintiles of hs-cTnT (hazard ratio [HR] 2.16, 95% confidence interval [CI] 1.82-2.58, P < .001) predicted MACEs. Among patients with hs-cTnT >0.014 μg/L at admission, 102 patients (31%) were on corticosteroids and showed lower hs-cTnT increase (P = .021), (NADPH) oxidase-2 (Nox2) activation (P = .005) and incidence of MACEs than untreated ones (HR 0.64, 95% CI 0.41-0.97, P = .038); no effect of corticosteroids on MACEs was observed in CAP patients with normal troponin. In vitro study showed that glucocorticoids have an antioxidant effect via downregulation of Nox2 activity.

CONCLUSION AND IMPLICATIONS

The study provides evidence that corticosteroid use is associated with lower increase of hs-cTnT and incidence of MACEs in CAP patients.

Long-term follow-up of patients with venous thromboembolism and COVID-19: Analysis of risk factors for death and major bleeding

INTRODUCTION

COVID-19 predisposes patients to a higher risk of venous thromboembolism (VTE), although the extent of these implications is unclear and the risk of bleeding has been poorly evaluated. To date, no studies have reported long-term outcomes of patients with COVID-19 and VTE.

METHOD

Prospective observational study to evaluate long-term (90 days or more) outcomes of patients diagnosed with VTE (PE, DVT of the extremities, or both) in the setting of COVID-19. The main outcome of the study was a compound of major bleeding and death.

RESULTS

The study comprised 100 patients (mean age 65 ± 13.9 years). At the time of VTE diagnosis, 66% patients were hospitalized, 34.8% of them in the ICU. Mean follow-up was 97.9 ± 23.3 days. During the study period, 24% patients died and median time to death was 12 (IQR: 2.25-20.75) days, 11% patients had major bleeding and median time to event was 12 (IQR: 5-16) days. The cause of death was PE in 5% and bleeding in 2% of patients. There were no VTE recurrences. The main study outcome occurred in 29% patients. Risk of death or major bleeding was independently associated with ICU admission (HR 12.2; 95% CI 3.0-48.3), thrombocytopenia (HR 4.5; 95% CI 1.2-16.5), and cancer (HR 21.6; 95% CI 1.8-259).

CONCLUSION

In patients with COVID-19 and VTE, mortality and major bleeding were high and almost a third of deaths were VTE-related. The majority of complications occurred in the first 30 days. ICU admission, thrombocytopenia, and cancer are risk factors for poor prognosis.

Infection, atherothrombosis and thromboembolism beyond the COVID-19 disease: what similar in physiopathology and researches

The recent Sars-Cov-2 pandemic (COVID-19) has led to growing research on the relationship between thromboembolism and Sars-Cov-2 infection. Nowadays, endothelial dysfunction, platelet activation, coagulation, and inflammatory host immune response are the subject of extensive researches in patients with COVID-19 disease. However, studies on the link between microorganisms or infections and thrombotic or thromboembolic events met fluctuating interest in the past. We, therefore, aimed to briefly summarize previous evidence on this topic, highlighting common points between previous data and what experienced today with SARS-COV2 infections.

Microbial Modulation of Coagulation Disorders in Venous Thromboembolism

Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is the third leading cause of cardiovascular death in the world. Important risk factors of thrombosis include bed restraint, surgery, major trauma, long journeys, inflammation, pregnancy, and oral contraceptives, previous venous thromboembolism, cancer, and bacterial infections. Sepsis increases the risk of blood clot formation 2–20 times. In this review, we discussed various mechanisms related to the role of bacteria in venous thrombosis also taking into consideration the role of the human microbiome. Many known bacteria, such as Helicobacter pylori, Chlamydia pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus, and Escherichia coli, causing infections may increase the risk of thrombotic complications through platelet activation or may lead to an inflammatory reaction involving the fibrinolytic system. Additionally, the bacteria participate in the production of factors causing or increasing the risk of cardiovascular diseases. An example can be trimethylamine N-oxide (TMAO) but also uremic toxins (indoxyl sulfate), short-chain fatty acids (SCFA) phytoestrogens, and bile acids. Finally, we presented the involvement of many bacteria in the development of venous thromboembolism and other cardiovascular diseases.

Coronavirus Disease 2019 and the Myocardium

Infection with the coronavirus known as COVID-19 has promoted growing interest on the part of cardiologists, emergency care specialists, intensive care specialists, and researchers, due to the study of myocardial involvement based on different clinical forms resulting from immunoinflammatory and neurohumoral demodulation.Myocardial involvement may be minimal and identifiable only by electrocardiographic changes, mainly increased cardiac troponins, or, on the other side of the spectrum, by forms of fulminant myocarditis and takotsubo syndrome.The description of probable acute myocarditis has been widely supported by the observation of increased troponin in association with dysfunction. Classical definition of myocarditis, supported by endomyocardial biopsy of inflammatory infiltrate, is rare; it has been observed in only one case report to date, and the virus has not been identified inside cardiomyocytes.Thus, the phenomenon that has been documented is acute myocardial injury, making it necessary to rule our obstructive coronary disease based on increased markers of myocardial necrosis, whether or not they are associated with ventricular dysfunction, likely associated with cytokine storms and other factors that may synergistically promote myocardial injury, such as sympathetic hyperactivation, hypoxemia, arterial hypotension, and microvascular thrombotic phenomena.Systemic inflammatory and myocardial phenomena following viral infection have been well documented, and they may progress to cardiac remodeling and myocardial dysfunction. Cardiac monitoring of these patients is, therefore, important in order to monitor the development of the phenotype of dilated myocardiopathy.This review presents the main etiological and physiopathological findings, a description of the taxonomy of these types of cardiac involvement, and their correlation with the main clinical forms of the myocardial component present in patients in the acute phase of COVID-19.

Pulmonary Vascular Manifestations of COVID-19 Pneumonia

PURPOSE

To investigate pulmonary vascular abnormalities at CT pulmonary angiography (CT-PE) in patients with coronavirus disease 2019 (COVID-19) pneumonia.

MATERIALS AND METHODS

In this retrospective study, 48 patients with reverse-transcription polymerase chain reaction-confirmed COVID-19 infection who had undergone CT-PE between March 23 and April 6, 2020, in a large urban health care system were included. Patient demographics and clinical data were collected through the electronic medical record system. Twenty-five patients underwent dual-energy CT (DECT) as part of the standard CT-PE protocol at a subset of the hospitals. Two thoracic radiologists independently assessed all studies. Disagreement in assessment was resolved by consensus discussion with a third thoracic radiologist.

RESULTS

Of the 48 patients, 45 patients required admission, with 18 admitted to the intensive care unit, and 13 requiring intubation. Seven patients (15%) were found to have pulmonary emboli. Dilated vessels were seen in 41 cases (85%), with 38 (78%) and 27 (55%) cases demonstrating vessel enlargement within and outside of lung opacities, respectively. Dilated distal vessels extending to the pleura and fissures were seen in 40 cases (82%) and 30 cases (61%), respectively. At DECT, mosaic perfusion pattern was observed in 24 cases (96%), regional hyperemia overlapping with areas of pulmonary opacities or immediately surrounding the opacities were seen in 13 cases (52%), opacities associated with corresponding oligemia were seen in 24 cases (96%), and hyperemic halo was seen in 9 cases (36%).

CONCLUSION

Pulmonary vascular abnormalities such as vessel enlargement and regional mosaic perfusion patterns are common in COVID-19 pneumonia. Perfusion abnormalities are also frequently observed at DECT in COVID-19 pneumonia and may suggest an underlying vascular process.Supplemental material is available for this article.© RSNA, 2020.

COVID-19 for the Cardiologist: Basic Virology, Epidemiology, Cardiac Manifestations, and Potential Therapeutic Strategies

Coronavirus disease-2019 (COVID-19), a contagious disease caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), has reached pandemic status. As it spreads across the world, it has overwhelmed health care systems, strangled the global economy, and led to a devastating loss of life. Widespread efforts from regulators, clinicians, and scientists are driving a rapid expansion of knowledge of the SARS-CoV-2 virus and COVID-19. The authors review the most current data, with a focus on the basic understanding of the mechanism(s) of disease and translation to the clinical syndrome and potential therapeutics. The authors discuss the basic virology, epidemiology, clinical manifestation, multiorgan consequences, and outcomes. With a focus on cardiovascular complications, they propose several mechanisms of injury. The virology and potential mechanism of injury form the basis for a discussion of potential disease-modifying therapies.

Corticosteroid Use and Incident Myocardial Infarction in Adults Hospitalized for Community-acquired Pneumonia

RATIONALE

Adults hospitalized for community-acquired pneumonia (CAP) have an increased risk of myocardial infarction. Corticosteroid treatment lowers CAP morbidity and mortality, but it is not known whether it influences in-hospital myocardial infarction.

OBJECTIVES

The aim of the present study was to investigate the potential interplay between corticosteroid treatment and in-hospital myocardial infarction in adults with CAP.

METHODS

We retrospectively analyzed adults with CAP referred to the University Hospital Policlinico Umberto I (Rome, Italy), consecutively recruited, and prospectively followed until discharge. The primary outcome was the occurrence of myocardial infarction during hospitalization. We used propensity score-adjusted Cox models to examine the association between corticosteroid use and myocardial infarction.

RESULTS

Seven hundred fifty-eight patients (493 males, 265 females; mean ± standard deviation age, 71.7 ± 14.4 yr) were included in the study. Of these, 241 (32%) were treated with systemic corticosteroids (methylprednisolone, betamethasone, or prednisone). During follow-up, 62 (8.2%) had a myocardial infarction during their hospitalization (incidence, 0.72 per 100 person-days; 95% confidence interval [CI], 0.55 to 0.92). Those treated with corticosteroids had a lower incidence of myocardial infarction (0.42 per 100 person-days) than those not treated with corticosteroids (0.89 per 100 person-days; absolute rate difference, -0.48 per 100 person-days; 95% CI, -0.85 to -0.10). In a propensity score-adjusted Cox model, corticosteroid use was associated with a lower incidence of myocardial infarction (hazard ratio, 0.46; 95% CI, 0.24 to 0.88; P = 0.02).

CONCLUSIONS

We found that in-hospital corticosteroid treatment was associated with a lower incidence of myocardial infarction in adults hospitalized with CAP.

Influence of COVID-19 on Cerebrovascular Disease and its Possible Mechanism

The global spread of COVID-19 has caused a substantial societal burden and become a major global public health issue. The COVID-19 elderly population with hypertension, diabetes, cardiovascular, and cerebrovascular diseases are at risk. Mortality rates are highest in these individuals if infected with COVID-19. Although the lungs are the main organs involved in acute respiratory distress syndrome caused by COVID-19 infection, COVID-19 triggers inflammatory and immune mechanisms, inducing a "cytokine storm" that aggravates disease progression and may lead to death. Presently, effective drugs are lacking, although current studies have confirmed that drugs with therapeutic potential include redaciclovir, lopinavir/ritonavir combined with interferon-β, convalescent plasma, and monoclonal antibodies. Currently, the most reasonable and effective way to prevent COVID-19 is to control the source of infection, terminate routes of transmission, and protect susceptible populations. With the rise of COVID-19 in China and worldwide, further prevention, diagnosis, and treatment measures are a critical unmet need. Cerebrovascular disease has high incidence, disability rate, and fatality rate. COVID-19 patient outcomes may also be complicated with acute stroke. This paper summarizes the influence of COVID-19 on cerebrovascular disease and discusses possible pathophysiological mechanisms to provide new angles for the prevention and diagnosis of this disease.

The Role of Stroke as a Trigger for Incident Venous Thromboembolism: Results from a Population-based Case-Crossover Study

Stroke is associated with a short-term increased risk of subsequent venous thromboembolism (VTE). It is unclear to what extent this association is mediated by stroke-related complications that are potential triggers for VTE, such as immobilization and infection. We aimed to investigate the role of acute stroke as a trigger for incident VTE while taking other concomitant VTE triggers into account. We conducted a population-based case-crossover study with 707 VTE patients. Triggers were registered during the 90 days before a VTE event (hazard period) and in four preceding 90-day control periods. Conditional logistic regression was used to estimate odds ratios with 95% confidence intervals (CIs) for VTE according to triggers. Stroke was registered in 30 of the 707 (4.2%) hazard periods and in 6 of the 2,828 (0.2%) control periods, resulting in a high risk of VTE, with odds ratios of 20.0 (95% CI: 8.3–48.1). After adjustments for immobilization and infection, odds ratios for VTE conferred by stroke were attenuated to 6.0 (95% CI: 1.6–22.1), and further to 4.0 (95% CI: 1.1–14.2) when other triggers (major surgery, red blood cell transfusion, trauma, and central venous catheter) were added to the regression model. A mediation analysis revealed that 67.8% of the total effect of stroke on VTE risk could be mediated through immobilization and infection. Analyses restricted to ischemic stroke yielded similar results. In conclusion, acute stroke was a trigger for VTE, and the association between stroke and VTE risk appeared to be largely mediated by immobilization and infection.

[Cerebral embolism in Duchenne muscular dystrophy after respiratory tract infection - Report of two cases]

We report cerebral embolism in 2 patients with Duchenne muscular dystrophy (DMD) after respiratory tract infection. A 31-year-old man (Case 1) was admitted to the hospital because of an upper respiratory tract infection, then suddenly developed left-sided hemiparesis. Transthoracic echocardiography revealed an intracardiac thrombus in the left ventricle, and, under assumption of cardioembolic stroke, oral anticoagulation was initiated. Case 2 was a 36-year-old man who developed dysphasia after increasing sputum. Based on brain CT scan findings, we confirmed a diagnosis of cerebral infarction. There was no recurrence in either case. Both cases developed cerebral infarction due to embolism after mild upper respiratory tract infections. DMD patients have various risk factors for thrombus and embolus, while physicians should also be aware of possible cerebral infarction and other coagulation disorders irrespective of respiratory and cardiac therapy.

Inflammation, Immunity, and Infection in Atherothrombosis: JACC Review Topic of the Week

Observations on human and experimental atherosclerosis, biomarker studies, and now a large-scale clinical trial support the operation of immune and inflammatory pathways in this disease. The factors that incite innate and adaptive immune responses implicated in atherogenesis and in lesion complication include traditional risk factors such as protein and lipid components of native and modified low-density lipoprotein, angiotensin II, smoking, visceral adipose tissue, and dysmetabolism. Infectious processes and products of the endogenous microbiome might also modulate atherosclerosis and its complications either directly, or indirectly by eliciting local and systemic responses that potentiate disease expression. Trials with antibiotics have not reduced recurrent cardiovascular events, nor have vaccination strategies yet achieved clinical translation. However, anti-inflammatory interventions such as anticytokine therapy and colchicine have begun to show efficacy in this regard. Thus, inflammatory and immune mechanisms can link traditional and emerging risk factors to atherosclerosis, and offer novel avenues for therapeutic intervention.

Glucocorticoids impair platelet thromboxane biosynthesis in community-acquired pneumonia

Previous reports suggest that community-acquired pneumonia (CAP) is associated with an enhanced risk of myocardial infarction (MI) and that enhanced platelet activation may play a role. Aims of this study were to investigate if urinary excretion of 11-dehydro-thromboxane (Tx) B₂, a reliable marker of platelet activation in vivo, was elevated in CAP and whether glucocorticoid administration reduced platelet activation. Three-hundred patients hospitalized for CAP were recruited and followed-up until discharge. Within the first 2 days from admission, urinary 11-dehydro-TxB₂ and serum levels of methylprednisolone and betamethasone were measured. 11-Dehydro-TxB₂ was also measured in a control group of 150 outpatients, matched for age, sex, and comorbidities. Finally, in-vitro studies were performed to assess if glucocorticoids affected platelet activation, at the same range of concentration found in the peripheral circulation of CAP patients treated with glucocorticoids. Compared to controls, CAP patients showed significantly higher levels of 11-dehydro-TxB₂ (110 [69-151] vs. 163 [130-225] pg/mg creatinine; p < 0.001). During the in-hospital stay, 31 patients experienced MI (10%). A COX regression analysis showed that 11-dehydro-TxB₂ independently predicted MI (p = .005). CAP patients treated with glucocorticoids showed significantly lower levels of 11-dehydro-TxB₂ compared to untreated ones (147 [120-201] vs. 176 [143-250] pg/mg creatinine; p < 0.001). In vitro, glucocorticoids-treated platelets showed a dose-dependent decrease of ADP-induced platelet aggregation, TxB₂ production, cPLA₂ phosphorylation and arachidonic acid release from the platelet membrane. In conclusion, platelet TxB₂ is overproduced in CAP patients and may be implicated in MI occurrence. Glucocorticoids reduce platelet release of TxB₂ in vitro and urinary excretion of 11-dehydro-TxB₂ in vivo and may be a novel tool to decrease platelet activation in this setting.

Cardiovascular Complications and Short-term Mortality Risk in Community-Acquired Pneumonia

Background.

Previous reports suggest that community-acquired pneumonia (CAP) is associated with an enhanced risk of cardiovascular complications. However, a contemporary and comprehensive characterization of this association is lacking.

Methods.

In this multicenter study, 1182 patients hospitalized for CAP were prospectively followed for up to 30 days after their hospitalization for this infection. Study endpoints included myocardial infarction, new or worsening heart failure, atrial fibrillation, stroke, deep venous thrombosis, cardiovascular death, and total mortality.

Results.

Three hundred eighty (32.2%) patients experienced intrahospital cardiovascular events (CVEs) including 281 (23.8%) with heart failure, 109 (9.2%) with atrial fibrillation, 89 (8%) with myocardial infarction, 11 (0.9%) with ischemic stroke, and 1 (0.1%) with deep venous thrombosis; 28 patients (2.4%) died for cardiovascular causes. Multivariable Cox regression analysis showed that intrahospital Pneumonia Severity Index (PSI) class (hazard ratio [HR], 2.45, P = .027; HR, 4.23, P < .001; HR, 5.96, P < .001, for classes III, IV, and V vs II, respectively), age (HR, 1.02, P = .001), and preexisting heart failure (HR, 1.85, P < .001) independently predicted CVEs. One hundred three (8.7%) patients died by day 30 postadmission. Thirty-day mortality was significantly higher in patients who developed CVEs compared with those who did not (17.6% vs 4.5%, P < .001). Multivariable Cox regression analysis showed that intrahospital CVEs (HR, 5.49, P < .001) independently predicted 30-day mortality (after adjustment for age, PSI score, and preexisting comorbid conditions).

Conclusions.

CVEs, mainly those confined to the heart, complicate the course of almost one-third of patients hospitalized for CAP. More importantly, the occurrence of CVEs is associated with a 5-fold increase in CAP-associated 30-day mortality.

Acute infection as a trigger for incident venous thromboembolism: Results from a population-based case-crossover study

BACKGROUND

A bidirectional relation exists between acute infection and immobilization, and both are triggers for venous thromboembolism (VTE). To what extent the association between infection and VTE-risk is explained by immobilization is unknown.

AIMS

To investigate the impact of hospitalization with acute infection on the VTE-risk in patients with and without concomitant immobilization, and to explore the differential impact of respiratory- (RTI) and urinary- (UTI) tract infections on the risk of deep vein thrombosis (DVT) and pulmonary embolism (PE).

METHODS

We conducted a case-crossover study of VTE-patients (n = 707) recruited from a general population. Hospitalizations and VTE-triggers were registered during the 90 days before a VTE (hazard period) and in four preceding 90-day control periods. Conditional logistic regression was used to estimate odds ratios (ORs) for VTE according to triggers.

RESULTS

Acute infection was registered in 267 (37.8%) of the hazard periods and in 107 (3.8%) of the control periods, corresponding to a high VTE-risk after infection (OR 24.2, 95% CI 17.2-34.0), that was attenuated to 15-fold increased after adjustment for immobilization. The risk was 20-fold increased after infection without concomitant immobilization, 73-fold increased after immobilization without infection, and 141-fold increased with the two combined. The risk of PE was apparently higher after RTIs (OR 48.3, 95% CI 19.4-120.0) than UTIs (OR 12.6, 95% CI 6.4-24.7), but diminished in sensitivity analyses excluding uncertain RTI diagnoses.

CONCLUSIONS

Our findings suggest that hospitalization with infection is a strong VTE-trigger also in non-immobilized patients. Infection and immobilization had a synergistic effect on the VTE-risk.

Predicting 30-Day Pneumonia Readmissions Using Electronic Health Record Data

BACKGROUND

Readmissions after hospitalization for pneumonia are common, but the few risk-prediction models have poor to modest predictive ability. Data routinely collected in the electronic health record (EHR) may improve prediction.

OBJECTIVE

To develop pneumonia-specific readmission risk-prediction models using EHR data from the first day and from the entire hospital stay ("full stay").

DESIGN

Observational cohort study using stepwise-backward selection and cross-validation.

SUBJECTS

Consecutive pneumonia hospitalizations from 6 diverse hospitals in north Texas from 2009-2010.

MEASURES

All-cause nonelective 30-day readmissions, ascertained from 75 regional hospitals.

RESULTS

Of 1463 patients, 13.6% were readmitted. The first-day pneumonia-specific model included sociodemographic factors, prior hospitalizations, thrombocytosis, and a modified pneumonia severity index; the full-stay model included disposition status, vital sign instabilities on discharge, and an updated pneumonia severity index calculated using values from the day of discharge as additional predictors. The full-stay pneumonia-specific model outperformed the first-day model (C statistic 0.731 vs 0.695; P = 0.02; net reclassification index = 0.08). Compared to a validated multi-condition readmission model, the Centers for Medicare and Medicaid Services pneumonia model, and 2 commonly used pneumonia severity of illness scores, the full-stay pneumonia-specific model had better discrimination (C statistic range 0.604-0.681; P < 0.01 for all comparisons), predicted a broader range of risk, and better reclassified individuals by their true risk (net reclassification index range, 0.09-0.18).

CONCLUSIONS

EHR data collected from the entire hospitalization can accurately predict readmission risk among patients hospitalized for pneumonia. This approach outperforms a first-day pneumonia-specific model, the Centers for Medicare and Medicaid Services pneumonia model, and 2 commonly used pneumonia severity of illness scores. Journal of Hospital Medicine 2017;12:209-216.

Serum amyloid A, protein Z, and C4b-binding protein β chain as new potential biomarkers for pulmonary tuberculosis

The aim of this study was to discover novel biomarkers for pulmonary tuberculosis (TB). Differentially expressed proteins in the serum of patients with TB were screened and identified by iTRAQ-two dimensional liquid chromatography tandem mass spectrometry analysis. A total of 79 abnormal proteins were discovered in patients with TB compared with healthy controls. Of these, significant differences were observed in 47 abnormally expressed proteins between patients with TB or pneumonia and chronic obstructive pulmonary disease (COPD). Patients with TB (n = 136) exhibited significantly higher levels of serum amyloid A (SAA), vitamin K-dependent protein Z (PROZ), and C4b-binding protein β chain (C4BPB) than those in healthy controls (n = 66) (P<0.0001 for each) albeit significantly lower levels compared with those in patients with pneumonia (n = 72) (P<0.0001 for each) or COPD (n = 72) (P<0.0001, P<0.0001, P = 0.0016, respectively). After 6 months of treatment, the levels of SAA and PROZ were significantly increased (P = 0.022, P<0.0001, respectively), whereas the level of C4BPB was significantly decreased (P = 0.0038) in treated TB cases (n = 72). Clinical analysis showed that there were significant differences in blood clotting and lipid indices in patients with TB compared with healthy controls, patients with pneumonia or COPD, and treated TB cases (P<0.05). Correlation analysis revealed significant correlations between PROZ and INR (rs = 0.414, P = 0.044), and between C4BPB and FIB (rs = 0.617, P = 0.0002) in patients with TB. Receiver operating characteristic curve analysis revealed that the area under the curve value of the diagnostic model combining SAA, PROZ, and C4BPB to discriminate the TB group from the healthy control, pneumonia, COPD, and cured TB groups was 0.972, 0.928, 0.957, and 0.969, respectively. Together, these results suggested that SAA, PROZ, and C4BPB may serve as new potential biomarkers for TB. Our study may thus provide experimental data for the differential diagnosis of TB.

Hospitalization with infection and incident venous thromboembolism: The ARIC study

BACKGROUND AND OBJECTIVES

Acute triggers for VTE, which may include infection, are understudied, as is the timing and duration of VTE risk after infection. We hypothesized that there is an association between hospitalization with infection and short-term VTE risk that exceeds the known association between hospitalization and VTE.

METHODS

VTE cases and infections were identified in the Atherosclerosis Risk in Communities (ARIC) cohort. A case-crossover design and conditional logistic regression were used to compare hospitalized infections among VTE cases (14, 30, 42, and 90days before VTE) with corresponding control periods 1year and 2years prior. Since hospitalization is a known VTE trigger, study design and analytical techniques were used to isolate the impact of infection.

RESULTS

There were 845 adjudicated incident VTE cases. Hospitalization with infection was more common in all case periods compared to equivalent control periods: 14day OR (95% CI)=1.7 (0.5, 5.8), 30day OR (95% CI)=2.7 (1.1, 6.4), 42day OR (95% CI)=2.2 (1.1, 4.7), and 90day OR (95% CI)=1.2 (0.7, 2.0). The association was generally strongest in exposure periods closest to the VTE event and decreased as the time window before VTE increased.

CONCLUSIONS

These results support the hypothesis that hospitalized infection is a trigger of VTE. VTE preventive measures may prevent VTE events if used in the peri-infection period but clinical trials are needed.

Clinical characteristics of pulmonary embolism with concomitant pneumonia

Although pneumonia is associated with an increased risk of venous thromboembolism, patients with pulmonary embolism and concomitant pneumonia are uncommon. The aim of the present study was to investigate the clinical features of pulmonary embolism with coexisting pneumonia. We retrospectively compared clinical, radiologic and laboratory parameters between patients with pulmonary embolism and concomitant pneumonia (pneumonia group) and those with unprovoked pulmonary embolism (unprovoked group), and then between the pneumonia group and those with pulmonary infarction (infarction group). Of 794 patients with pulmonary embolism, 36 (5%) had coexisting pneumonia and six (1%) had no provoking factor other than pneumonia. Stroke was significantly more common in the pneumonia group, than either the unprovoked group or the infarction group. In the pneumonia group, fever was significantly more common and serum C-reactive protein levels were significantly higher. By contrast, central pulmonary embolism and right ventricular dilation on computed tomography were significantly less frequent in the pneumonia group. In addition, an adverse outcome due to pulmonary embolism was less common in the pneumonia group than in either of the other two groups. The coexistence of pulmonary embolism and pneumonia is rarely encountered in clinical practice, especially without the presence of other factors that could provoke venous thromboembolism and is commonly associated with stroke. It is characterized by lower incidences of central pulmonary embolism and right ventricular dilation and by a lower rate of adverse outcomes due to pulmonary embolism itself.

Impaired flow-mediated dilation in hospitalized patients with community-acquired pneumonia

BACKGROUND

Community-acquired pneumonia (CAP) is complicated by cardiovascular events as myocardial infarction and stroke but the underlying mechanism is still unclear. We hypothesized that endothelial dysfunction may be implicated and that endotoxemia may have a role.

METHODS

Fifty patients with CAP and 50 controls were enrolled. At admission and at discharge, flow-mediated dilation (FMD), serum levels of endotoxins and oxidative stress, as assessed by serum levels of nitrite/nitrate (NOx) and isoprostanes, were studied.

RESULTS

At admission, a significant difference between patients with CAP and controls was observed for FMD (2.1±0.3 vs 4.0±0.3%, p<0.001), serum endotoxins (157.8±7.6 vs 33.1±4.8pg/ml), serum isoprostanes (341±14 vs 286±10 pM, p=0.009) and NOx (24.3±1.1 vs 29.7±2.2μM). Simple linear correlation analysis showed that serum endotoxins significantly correlated with Pneumonia Severity Index score (Rs=0.386, p=0.006). Compared to baseline, at discharge CAP patients showed a significant increase of FMD and NOx (from 2.1±0.3 to 4.6±0.4%, p<0.001 and from 24.3±1.1 to 31.1±1.5μM, p<0.001, respectively) and a significant decrease of serum endotoxins and isoprostanes (from 157.8±7.6 to 55.5±2.3pg/ml, p<0.001, and from 341±14 to 312±14 pM, p<0.001, respectively). Conversely, no changes for FMD, NOx, serum endotoxins and isoprostanes were observed in controls between baseline and discharge. Changes of FMD significantly correlated with changes of serum endotoxins (Rs=-0.315; p=0.001).

CONCLUSIONS

The study provides the first evidence that CAP is characterized by impaired FMD with a mechanism potentially involving endotoxin production and oxidative stress.

Low-grade endotoxemia and clotting activation in the early phase of pneumonia

BACKGROUND AND OBJECTIVE

Community-acquired pneumonia (CAP) is associated with an increased risk of arterial and venous thrombosis but the underlying pathophysiological mechanisms are still unclear. We investigated if, in patients with CAP, a pro-thrombotic state does exist and its relationship with serum levels of endotoxins.

METHODS

A total of 104 consecutive patients with CAP were prospectively recruited and followed up until discharge. At admission and at discharge, serum endotoxins, systemic markers of clotting activation and zonulin, a marker of gut permeability, were analysed. Hospitalized patients matched for gender, age and comorbidities but without infections were used as control.

RESULTS

At admission, CAP patients showed higher plasma levels of F₁₊₂ , a marker of thrombin generation (P = 0.023), and lower levels of protein C (PC; P < 0.001) and activated PC (aPC) (P < 0.001) compared with controls. At discharge, plasma levels of both PC and aPC significantly increased while F₁₊₂ significantly decreased (P < 0.001). Baseline serum endotoxins and zonulin were higher in CAP patients than controls (P < 0.001) and significantly decreased at discharge; a significant correlation between serum endotoxins and zonulin was detected (R = 0.575; P < 0.001) CONCLUSION: This study provides the first evidence that CAP patients disclose an ongoing pro-thrombotic state and suggests a role for endotoxemia in determining enhanced thrombin generation.

Low-grade endotoxemia, gut permeability and platelet activation in community-acquired pneumonia

OBJECTIVES

Platelet activation seems to be implicated in the cardiovascular events occurring in patients with community-acquired pneumonia (CAP) but the underlying mechanism is still unclear. Aim of the study was to assess the mechanism involved in platelet activation in CAP patients.

METHODS

Two-hundred-seventy-eight consecutive patients hospitalized for CAP were recruited and followed-up until discharge. Hospitalized patients matched for sex, age and comorbidities but without acute infectious diseases were used as controls.

RESULTS

At hospital admission patients disclosed enhanced plasma levels of sP-selectin, a maker of in-vivo platelet activation, serum sNOX2-dp, a marker of NADPH-oxidase activation, serum Lipopolysaccharide (LPS) and serum zonulin, a marker of gut permeability, compared to controls (p < 0.001). Baseline sP-selectin was independently associated to serum LPS, sNOX2-sp and Pneumonia Severity Index score (p < 0.001). Plasma sP-selectin, serum sNOX2-dp, LPS and zonulin coincidentally decreased at hospital discharge (p < 0.001). An in vitro study showed that LPS, at concentration similar to that found in CAP patients, induced sP-selectin release by agonist-activated platelets, a phenomenon that was counteract by treating cells with gp91ds-tat, a specific inhibitor of NOX2.

CONCLUSIONS

CAP patients display enhanced platelet activation, which is related to LPS-mediated NOX2 activation. Enhanced gut permeability seems be implicated in enhancing circulating levels of LPS.

Postprimary Tuberculosis and Macrophage Necrosis: Is There a Big ConNECtion?

Adult or postprimary tuberculosis (TB) accounts for most TB cases. Its hallmark is pulmonary cavitation, which occurs as a result of necrosis in the lung in individuals with tuberculous pneumonia. Postprimary TB has previously been known to be associated with vascular thrombosis and delayed-type hypersensitivity, but their roles in pulmonary cavitation are unclear. A necrosis-associated extracellular cluster (NEC) refers to a cluster of drug-tolerant Mycobacterium tuberculosis attached to lysed host materials and is proposed to contribute to granulomatous TB. Here we suggest that NECs, perhaps due to big size, produce a distinct host response leading to postprimary TB. We propose that vascular thrombosis and pneumonia arise from NEC and that these processes are promoted by inflammatory cytokines produced from cell-mediated delayed-type hypersensitivity, such as interleukin-17 and gamma interferon, eventually triggering necrosis in the lung and causing cavitation. According to this view, targeting NEC represents a necessary strategy to control adult TB.

Relation of Cardiac Complications in the Early Phase of Community-Acquired Pneumonia to Long-Term Mortality and Cardiovascular Events

Community-acquired pneumonia (CAP) is complicated by cardiac events in the early phase of the disease. Aim of this study was to assess if these intrahospital cardiac complications may account for overall mortality and cardiovascular events occurring during a long-term follow-up. Three hundred one consecutive patients admitted to the University-Hospital, Policlinico Umberto I, with community-acquired pneumonia were prospectively recruited and followed up for a median of 17.4 months. Primary end point was the occurrence of death for any cause, and secondary end point was the occurrence of cardiovascular events (cardiovascular death, nonfatal myocardial infarction [MI], and stroke). During the intrahospital stay, 55 patients (18%) experienced a cardiac complication. Of these, 32 had an MI (29 non-ST-elevation MI and 3 ST-elevation MI) and 30 had a new episode of atrial fibrillation (7 nonmutually exclusive events). During the follow-up, 89 patients died (51% of patients with an intrahospital cardiac complication and 26% of patients without, p <0.001) and 73 experienced a cardiovascular event (47% of patients with and 19% of patients without an intrahospital cardiac complication, p <0.001). A Cox regression analysis showed that intrahospital cardiac complications, age, and Pneumonia Severity Index were significantly associated with overall mortality, whereas intrahospital cardiac complications, age, hypertension, and diabetes were significantly associated with cardiovascular events during the follow-up. In conclusion, this prospective study shows that intrahospital cardiac complications in the early phase of pneumonia are associated with an enhanced risk of death and cardiovascular events during long-term follow-up.

Lower mortality rate in elderly patients with community-onset pneumonia on treatment with aspirin

BACKGROUND

Pneumonia is complicated by high rate of mortality and cardiovascular events (CVEs). The potential benefit of aspirin, which lowers platelet aggregation by inhibition of thromboxane A2 production, is still unclear. The aim of the study was to assess the impact of aspirin on mortality in patients with pneumonia.

METHODS AND RESULTS

Consecutive patients admitted to the University-Hospital Policlinico Umberto I (Rome, Italy) with community-onset pneumonia were recruited and prospectively followed up until discharge or death. The primary end point was the occurrence of death up to 30 days after admission; the secondary end point was the intrahospital incidence of nonfatal myocardial infarction and ischemic stroke. One thousand and five patients (age, 74.7±15.1 years) were included in the study: 390 were receiving aspirin (100 mg/day) at the time of hospitalization, whereas 615 patients were aspirin free. During the follow-up, 16.2% of patients died; among these, 19 (4.9%) were aspirin users and 144 (23.4%; P<0.001) were aspirin nonusers. Overall, nonfatal CVEs occurred in 7% of patients, 8.3% in nonaspirin users, and 4.9% in aspirin users (odds ratio, 1.77; 95% confidence interval, 1.03 to 3.04; P=0.040). The Cox regression analysis showed that pneumonia severity index (PSI), severe sepsis, pleural effusion, and PaO(2)/FiO(2) ratio <300 negatively influenced survival, whereas aspirin therapy was associated with improved survival. Compared to patients receiving aspirin, the propensity score adjusted analysis confirmed that patients not taking aspirin had a hazard ratio of 2.07 (1.08 to 3.98; P=0.029) for total mortality.

CONCLUSIONS

This study shows that chronic aspirin use is associated with lower mortality rate within 30 days after hospital admission in a large cohort of patients with pneumonia.