Risk of Acute Coronary Heart Disease After Sepsis Hospitalization in the REasons for Geographic and Racial Differences in Stroke (REGARDS) Cohort

The potential role of SARS‐CoV‐2 infection in acute coronary syndrome and type 2 myocardial infarction (T2MI): Intertwining spread

Coronavirus disease 2019 (COVID‐19) is a novel pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). It has been shown that SARS‐CoV‐2 infection‐induced inflammatory and oxidative stress and associated endothelial dysfunction may lead to the development of acute coronary syndrome (ACS). Therefore, this review aimed to ascertain the link between severe SARS‐CoV‐2 infection and ACS. ACS is a spectrum of acute myocardial ischemia due to a sudden decrease in coronary blood flow, ranging from unstable angina to myocardial infarction (MI). Primary or type 1 MI (T1MI) is mainly caused by coronary plaque rupture and/or erosion with subsequent occlusive thrombosis. Secondary or type 2 MI (T2MI) is due to cardiac and systemic disorders without acute coronary atherothrombotic disruption. Acute SARS‐CoV‐2 infection is linked with the development of nonobstructive coronary disorders such as coronary vasospasm, dilated cardiomyopathy, myocardial fibrosis, and myocarditis. Furthermore, SARS‐CoV‐2 infection is associated with systemic inflammation that might affect coronary atherosclerotic plaque stability through augmentation of cardiac preload and afterload. Nevertheless, major coronary vessels with atherosclerotic plaques develop minor inflammation during COVID‐19 since coronary arteries are not initially and primarily targeted by SARS‐CoV‐2 due to low expression of angiotensin‐converting enzyme 2 in coronary vessels. In conclusion, SARS‐CoV‐2 infection through hypercytokinemia, direct cardiomyocyte injury, and dysregulation of the renin‐angiotensin system may aggravate underlying ACS or cause new‐onset T2MI. As well, arrhythmias induced by anti‐COVID‐19 medications could worsen underlying ACS.

Combined Multiomics and In Silico Approach Uncovers PRKAR1A as a Putative Therapeutic Target in Multi-Organ Dysfunction Syndrome

Despite all epidemiological, clinical, and experimental research efforts, therapeutic concepts in sepsis and sepsis-induced multi-organ dysfunction syndrome (MODS) remain limited and unsatisfactory. Currently, gene expression data sets are widely utilized to discover new biomarkers and therapeutic targets in diseases. In the present study, we analyzed MODS expression profiles (comprising 13 sepsis and 8 control samples) retrieved from NCBI-GEO and found 359 differentially expressed genes (DEGs), among which 170 were downregulated and 189 were upregulated. Next, we employed the weighted gene co-expression network analysis (WGCNA) to establish a MODS-associated gene co-expression network (weighted) and identified representative module genes having an elevated correlation with age. Based on the results, a turquoise module was picked as our hub module. Further, we constructed the PPI network comprising 35 hub module DEGs. The DEGs involved in the highest-confidence PPI network were utilized for collecting pathway and gene ontology (GO) terms using various libraries. Nucleotide di- and triphosphate biosynthesis and interconversion was the most significant pathway. Also, 3 DEGs within our PPI network were involved in the top 5 significantly enriched ontology terms, with hypercortisolism being the most significant term. PRKAR1A was the overlapping gene between top 5 significant pathways and GO terms, respectively. PRKAR1A was considered as a therapeutic target in MODS, and 2992 ligands were screened for binding with PRKAR1A. Among these ligands, 3 molecules based on CDOCKER score (molecular dynamics simulated-based score, which allows us to rank the binding poses according to their quality and to identify the best pose for each system) and crucial interaction with human PRKAR1A coding protein and protein kinase-cyclic nucleotide binding domains (PKA RI alpha CNB-B domain) via active site binding residues, viz. Val283, Val302, Gln304, Val315, Ile327, Ala336, Ala337, Val339, Tyr373, and Asn374, were considered as lead molecules.

Long-term risk and predictors of cerebrovascular events following sepsis hospitalization: A systematic review and meta-analysis

Background

Long-term risk and predictors of cerebrovascular events following sepsis hospitalization have not been clearly elucidated. We aim to determine the association between surviving sepsis hospitalization and cerebrovascular complications in adult sepsis survivors.

Method

We searched MEDLINE, Embase, Scopus, Web of Sciences, Cochrane library, and Google scholar for studies published from the inception of each database until 31 August 2022.

Results

Of 8,601 screened citations, 12 observational studies involving 829,506 participants were analyzed. Surviving sepsis hospitalization was associated with a significantly higher ischemic stroke [adjusted hazard ratio (aHR) 1.45 (95% CI, 1.23-1.71), I ² = 96], and hemorrhagic stroke [aHR 2.22 (95% CI, 1.11-4.42), I ² = 96] at maximum follow-up compared to non-sepsis hospital or population control. The increased risk was robust to several sensitivity analyses. Factors that were significantly associated with increased hazards of stroke were: advanced age, male gender, diabetes mellitus, hypertension, coronary artery disease, chronic heart failure, chronic kidney disease, chronic obstruction pulmonary disease, and new-onset atrial fibrillation. Only diabetes mellites [aHR 1.80 (95% CI, 1.12-2.91)], hypertension [aHR 2.2 (95% CI, 2.03-2.52)], coronary artery disease [HR 1.64 (95% CI, 1.49-1.80)], and new-onset atrial fibrillation [aHR 1.80 (95% CI, 1.42-2.28)], were associated with > 50% increase in hazards.

Conclusion

Our findings showed a significant association between sepsis and a subsequent risk of cerebrovascular events. The risk of cerebrovascular events can be predicated by patient and sepsis-related baseline variables. New therapeutic strategies are needed for the high-risk patients.

Mechanisms of Post-critical Illness Cardiovascular Disease

Prolonged critical care stays commonly follow trauma, severe burn injury, sepsis, ARDS, and complications of major surgery. Although patients leave critical care following homeostatic recovery, significant additional diseases affect these patients during and beyond the convalescent phase. New cardiovascular and renal disease is commonly seen and roughly one third of all deaths in the year following discharge from critical care may come from this cluster of diseases. During prolonged critical care stays, the immunometabolic, inflammatory and neurohumoral response to severe illness in conjunction with resuscitative treatments primes the immune system and parenchymal tissues to develop a long-lived pro-inflammatory and immunosenescent state. This state is perpetuated by persistent Toll-like receptor signaling, free radical mediated isolevuglandin protein adduct formation and presentation by antigen presenting cells, abnormal circulating HDL and LDL isoforms, redox and metabolite mediated epigenetic reprogramming of the innate immune arm (trained immunity), and the development of immunosenescence through T-cell exhaustion/anergy through epigenetic modification of the T-cell genome. Under this state, tissue remodeling in the vascular, cardiac, and renal parenchymal beds occurs through the activation of pro-fibrotic cellular signaling pathways, causing vascular dysfunction and atherosclerosis, adverse cardiac remodeling and dysfunction, and proteinuria and accelerated chronic kidney disease.

Underestimated Ischemic Heart Disease in Major Adverse Cardiovascular Events after Septicemia Discharge

Background and Objectives: Sepsis increases cardiovascular disease and causes death. Ischemic heart disease (IHD) without acute myocardial infarction has been discussed less, and the relationship between risk factors and IHD in septicemia survivors within six months is worthy of in-depth study. Our study demonstrated the incidence of IHD and the possible risk factors for IHD in septicemia patients within six months. Materials and Methods: An inpatient dataset of the Taiwanese Longitudinal Health Insurance Database between 2001 and 2003 was used. The events were defined as rehospitalization of stroke and IHD after discharge or death within six months after the first septicemia hospitalization. The relative factors of major adverse cardiovascular events (MACEs) and IHD were identified by multivariate Cox proportional regression. Results: There were 4323 septicemia survivors and 404 (9.3%) IHD. New-onset atrial fibrillation had a hazard ratio (HR) of 1.705 (95% confidence interval (C.I.): 1.156–2.516) for MACEs and carried a 184% risk with HR 2.836 (95% C.I.: 1.725–4.665) for IHD by adjusted area and other risk factors. Conclusions: This study explored advanced-aged patients who experienced more severe septicemia with new-onset atrial fibrillation, which increases the incidence of IHD in MACEs within six months of septicemia. Therefore, healthcare providers must identify patients with a higher IHD risk and modify risk factors beforehand.

ST-Elevation Myocardial Infarction Among Septic Shock and Coronary Interventions: A National Emergency Database Study

OBJECTIVE

To study coronary interventions and mortality among patients with ST-elevated myocardial infarction (STEMI) who were admitted with septic shock.

METHODS

Data from the national emergency department sample (NEDS) that constitutes 20% sample of hospital-owned emergency departments in the United States was analyzed for the septic shock related visits from 2016 to 2018. Septic shock was defined by the ICD codes.

RESULTS

Out of 1 375 507 adult septic shock patients, 521 300 had a primary diagnosis of septic shock (mean age 67.41±15.67 years, 51.1% females) in the national emergency database for the years 2016 to 2018. Of these patients, 2768 (0.53%) had STEMI recorded during the hospitalization. Mortality rates for STEMI patients were higher than patients without STEMI (52.3% vs 23.5%). Mortality rates improved with PCI among STEMI patients (43.8% vs 56.2%). Coronary angiography was performed among 16% of patients of which percutaneous coronary intervention (PCI) rates were 7.7% among patients with STEMI septic shock. PCI numerically improved mortality, however, had no significant difference than patients without PCI on multivariate logistic regression and univariate logistic regression post coarsened exact matching of baseline characteristics among STEMI patients. Among the predictors, STEMI was a significant predictor of mortality in septic shock patients (OR 2.87, 95% CI 2.37-3.49; P<.001). Age, peripheral vascular disease, were predominant predictors of mortality in STEMI with septic shock subgroup (P <.001). Pneumonia was the predominant underlying infection among STEMI (36.4%) and without STEMI group (29.5%).

CONCLUSION

STEMI complicating septic shock worsens mortality. PCI and coronary angiography numerically improved mortality, however, had no significant difference from patients without PCI. More research will be needed to improve mortality in such a critically ill subgroup of patients.

Association between sepsis survivorship and long-term cardiovascular outcomes in adults: a systematic review and meta-analysis

PURPOSE

We aimed to determine the association between sepsis and long-term cardiovascular events.

METHODS

We conducted a systematic review of observational studies evaluating post-sepsis cardiovascular outcomes in adult sepsis survivors. MEDLINE, Embase, and the Cochrane Controlled Trials Register and Database of Systematic Reviews were searched from inception until April 21st, 2021. Two reviewers independently extracted individual study data and evaluated risk of bias. Random-effects models estimated the pooled crude cumulative incidence and adjusted hazard ratios (aHRs) of cardiovascular events compared to either non-septic hospital survivors or population controls. Primary outcomes included myocardial infarction, stroke, and congestive heart failure; outcomes were analysed at maximum reported follow-up (from 30 days to beyond 5 years post-discharge).

RESULTS

Of 12,649 screened citations, 27 studies (25 cohort studies, 2 case-crossover studies) were included with a median of 4,289 (IQR 502-68,125) sepsis survivors and 18,399 (IQR 4,028-83,506) controls per study. The pooled cumulative incidence of myocardial infarction, stroke, and heart failure in sepsis survivors ranged from 3 to 9% at longest reported follow-up. Sepsis was associated with a higher long-term risk of myocardial infarction (aHR 1.77 [95% CI 1.26 to 2.48]; low certainty), stroke (aHR 1.67 [95% CI 1.37 to 2.05]; low certainty), and congestive heart failure (aHR 1.65 [95% CI 1.46 to 1.86]; very low certainty) compared to non-sepsis controls.

CONCLUSIONS

Surviving sepsis may be associated with a long-term, excess hazard of late cardiovascular events which may persist for at least 5 years following hospital discharge.

Sepsis and Cancer: An Interplay of Friends and Foes

Sepsis and cancer share a number of pathophysiological features, and both result from the inability of the host's immune system to cope with the initial insult (tissue invasion by pathogens and malignant cell transformation, respectively). The common coexistence of both disorders and the profound related alterations in immune homeostasis raise the question of their mutual impact on each other's course. This translational review aims to discuss the interactions between cancer and sepsis supported by clinical data and the translation to experimental models. The dramatic improvement in cancer has come at a cost of increased risks of life-threatening infectious complications. Investigating the long-term outcomes of sepsis survivors has revealed an unexpected susceptibility to cancer long after discharge from the ICU. Nonetheless, it is noteworthy that an acute septic episode may harbor antitumoral properties under particular circumstances. Relevant double-hit animal models have provided clues to whether and how bacterial sepsis may impact malignant tumor growth. In sequential sepsis-then-cancer models, postseptic mice exhibited accelerated tumor growth. When using reverse cancer-then-sepsis models, bacterial sepsis applied to mice with cancer conversely resulted in inhibition or even regression of tumor growth. Experimental models thus highlight dual effects of sepsis on tumor growth, mostly depending on the sequence of insults, and allow deciphering the immune mechanisms and their relation with microorganisms.

Infection as a Cardiovascular Trigger: Associations Between Different Organ System Infections and Cardiovascular Events

BACKGROUND

Infection may be an acute precipitant of cardiovascular events. However, the relationships between different types of infection and cardiovascular events are less known. Our objective was to determine if exposure to infections of different organ systems in different time periods increases risk of myocardial infarction or venous thromboembolism.

METHOD

We used case-crossover analysis with conditional logistic regression to estimate odds ratios (OR) for the association for each infection type during 3 case periods (30, 60, and 90 days prior to index event) compared with control periods (exactly 1 year before).

RESULTS

This study had a total number of index admissions of 338,021 individuals, of which 82,986 were female; the mean age for individuals with myocardial infarction and venous thromboembolism was 68.48 years and 62.33 years, respectively. With every infection type, there was an increased likelihood of venous thromboembolism. The greatest association was for skin infections, with an OR of 5.39 (95% confidence interval, 4.08- 7.12) within the 7-day window. The association between myocardial infarction and skin infections was of lesser magnitude, with an OR of 2.89 (confidence interval, 1.97-4.24) in the 7-day exposure period.

CONCLUSION

We found a gradient of decreasing magnitudes of association with longer time periods, across the majority of infection types and cardiovascular events. This warrants potential interventions to prevent infection or cardiovascular disease prophylaxis in individuals with infection.

Risk Factors for Myocardial Infarction and Stroke Among Sepsis Survivors: A Competing Risks Analysis

Objectives:

Predictors for post-sepsis myocardial infarction (MI) and stroke are yet to be identified due to the competing risk of death.

Methods:

This study included all hospitalized patients with sepsis from National Health Insurance Research Database of Taiwan between 2000 and 2011. The primary outcome was the first occurrence of MI and stroke requiring hospitalization within 180 days following hospital discharge from the index sepsis episode. The association between predictors and post-sepsis MI and stroke were analyzed using cumulative incidence competing risk model that controlled for the competing risk of death.

Results:

Among 42 316 patients with sepsis, 1012 (2.4%) patients developed MI and stroke within 180 days of hospital discharge. The leading 5 predictors for post-sepsis MI and stroke are prior cerebrovascular diseases (hazard ratio [HR]: 2.02, 95% confidence interval [CI]: 1.74-2.32), intra-abdominal infection (HR: 1.94, 95% CI: 1.71-2.20), previous MI (HR: 1.81, 95% CI: 1.53-2.15), lower respiratory tract infection (HR: 1.62, 95% CI: 1.43-1.85), and septic encephalopathy (HR: 1.61, 95% CI: 1.26-2.06).

Conclusions:

Baseline comorbidities and sources of infection were associated with an increased risk of post-sepsis MI and stroke. The identified risk factors may help physicians select a group of patients with sepsis who may benefit from preventive measures, antiplatelet treatment, and other preventive measures for post-sepsis MI and stroke.

Organ Dysfunction in Sepsis: An Ominous Trajectory From Infection To Death

Sepsis is a highly complex and lethal syndrome with highly heterogeneous clinical manifestations that makes it difficult to detect and treat. It is also one of the major and most urgent global public health challenges. More than 30 million people are diagnosed with sepsis each year, with 5 million attributable deaths and long-term sequalae among survivors. The current international consensus defines sepsis as a life-threatening organ dysfunction caused by a dysregulated host response to an infection. Over the past decades substantial research has increased the understanding of its pathophysiology. The immune response induces a severe macro and microcirculatory dysfunction that leads to a profound global hypoperfusion, injuring multiple organs. Consequently, patients with sepsis might present dysfunction of virtually any system, regardless of the site of infection. The organs more frequently affected are kidneys, liver, lungs, heart, central nervous system, and hematologic system. This multiple organ failure is the hallmark of sepsis and determines patients' course from infection to recovery or death. There are tools to assess the severity of the disease that can also help to guide treatment, like the Sequential Organ Failure Assessment (SOFA) score. However, sepsis disease process is vastly heterogeneous, which could explain why interventions targeted to directly intervene its mechanisms have shown unsuccessful results and predicting outcomes with accuracy is still elusive. Thus, it is required to implement strong public health strategies and leverage novel technologies in research to improve outcomes and mitigate the burden of sepsis and septic shock worldwide.

Susceptible period for cardiovascular complications in patients recovering from sepsis

BACKGROUND

Patients are at increased risk of cardiovascular complications while recovering from sepsis. We aimed to study the temporal change and susceptible periods for cardiovascular complications in patients recovering from sepsis by using a national database.

METHODS

In this retrospective population-based cohort study, patients with sepsis were identified from the National Health Insurance Research Database in Taiwan. We estimated the risk of myocardial infarction (MI) and stroke following sepsis by comparing a sepsis cohort to a matched population and hospital control cohort. The primary outcome was first occurrence of MI or stroke requiring admission to hospital during the 180-day period following discharge from hospital after sepsis. To delineate the risk profile over time, we plotted the weekly risk of MI and stroke against time using the Cox proportional hazards model. We determined the susceptible period by fitting the 2 phases of time-dependent risk curves with free-knot splines, which highlights the turning point of the risk of MI and stroke after discharge from the hospital.

RESULTS

We included 42 316 patients with sepsis; stroke developed in 831 of these patients and MI developed in 184 within 180 days of discharge from hospital. Compared with population controls, patients recovering from sepsis had the highest risk for MI or stroke in the first week after discharge (hazard ratio [HR] 4.78, 95% confidence interval [CI] 3.19 to 7.17; risk difference 0.0028, 95% CI 0.0021 to 0.0034), with the risk decreasing rapidly until the 28th day (HR 2.38, 95% CI 1.94 to 2.92; risk difference 0.0045, 95% CI 0.0035 to 0.0056) when the risk stabilized. In a repeated analysis comparing the sepsis cohort with the nonsepsis hospital control cohort, we found an attenuated but still marked elevated risk before day 36 after discharge (HR 1.32, 95% CI 1.15 to 1.52; risk difference 0.0026, 95% CI 0.0013 to 0.0039). The risk of MI or stroke was found to interact with age, with younger patients being associated with a higher risk than older patients (interaction p = 0.0004).

INTERPRETATION

Compared with the general population with similar characteristics, patients recovering from sepsis had a markedly elevated risk of MI or stroke in the first 4 weeks after discharge from hospital. More close monitoring and pharmacologic prevention may be required for these patients at the specified time.

Impact of post-sepsis cardiovascular complications on mortality in sepsis survivors: a population-based study

BACKGROUND

It remains unclear whether sepsis-related cardiovascular complications have an adverse impact on survival independent of pre-existing comorbidities. To investigate the survival impact of post-sepsis cardiovascular complications among sepsis survivors, we conducted a population-based study using the National Health Insurance Database of Taiwan.

METHODS

We identified sepsis patients from the National Health Insurance Research Database of Taiwan using ICD-9-CM codes involving infection and organ dysfunction between 2000 and 2011. Post-sepsis incident myocardial infarction (MI) and stroke were ascertained by ICD-9-CM codes and antiplatelet treatment. We constructed a non-sepsis comparison cohort using propensity score matching to ascertain the association between sepsis and cardiovascular complications. Furthermore, we compared the 180-day mortality and 365-day mortality between patients surviving sepsis with or without post-sepsis MI or stroke within 70 days of hospital discharge. We constructed Cox regression models adjusting for pre-existing comorbidities to evaluate the independent survival impact of post-sepsis MI or stroke among sepsis survivors.

RESULTS

We identified 42,316 patients hospitalized for sepsis, from which we matched 42,151 patients 1:1 with 42,151 patients hospitalized without sepsis. Compared to patients hospitalized without sepsis, patients hospitalized with sepsis had an increased risk of MI or stroke (adjusted odds ratio 1.72, 95% CI 1.60-1.85). Among 42,316 patients hospitalized for sepsis, 486 (1.15%) patients developed incident stroke and 108 (0.26%) developed incident MI within 70 days of hospital discharge. Compared to sepsis survivors without cardiovascular complications, sepsis survivors with incident MI or stroke had a higher mortality rate at 180 days (11.68% vs. 4.44%, P = 0.003) and at 365 days (16.75% vs. 7.11%, P = 0.005). Adjusting for age, sex, and comorbidities, post-sepsis MI or stroke was independently associated with increased 180-day (adjusted hazard ratio [HR] 2.16, 95% CI 1.69-2.76) and 365-day (adjusted HR 1.90, 95% CI 1.54-2.32) mortality.

CONCLUSIONS

Compared to sepsis patients without incident MI or stroke, sepsis patients with incident MI or stroke following hospital discharge had an increased risk of mortality for up to 365 days of follow-up. This increased risk cannot be explained by pre-sepsis comorbidities.

Effect on Outcomes: Infections Complicating Percutaneous Coronary Interventions in Patients ≥80 Years of Age

Data on the prevalence of infections in patients who underwent percutaneous coronary intervention (PCI) and their impact on outcomes are scarce. In this study, a total of 644 patients ≥80 years of age who underwent PCI were stratified according to the presence/absence of infections requiring antibiotic therapy. The primary end point was major adverse cardiovascular events (MACE) after discharge, a composite of all-cause mortality, nonfatal myocardial infarction, and rehospitalization for heart failure. Median follow-up was 1.2 (interquartile range 0.1 to 3.4) years. Of the 644 patients, 186 (28.9%) had infections during index hospitalization, with 84 (13%) and 59 (9.2%) patients having pneumonia and urinary tract infections, respectively. Patients with infections were older, more often women, and had an increased prevalence of atrial fibrillation and congestive heart failure. Infections prolonged hospital stay (10 [7 to 16] vs 5 [3 to 7] days, p <0.001), but were not related to rates of MACE (20% vs 19%, adjusted hazard ratio [HR] 1.41, 95% confidence intervals 0.84 to 2.38, p = 0.20). Pneumonia was significantly associated with increased rates of MACE (27% vs 18%, adjusted HR 2.19, 95% confidence intervals 1.23 to 3.91, p = 0.008) and rehospitalization for heart failure (17% vs 10%, adjusted HR 2.66 (1.25 to 5.63, p = 0.01), whereas urinary tract infections were not. In conclusion, concomitant infections are frequent in patients ≥80 years of age who underwent PCI, and associated with an increased risk of adverse events when affecting the respiratory system.

Cardiovascular Events and Hospital Deaths Among Patients With Severe Sepsis

The burden of cardiovascular events among patients hospitalized with severe sepsis and the association of these events with in-hospital mortality is not well known. We examined the incidence of cardiovascular events and their association with in-hospital mortality among patients with severe sepsis. Patients with severe sepsis from the New York State Inpatient Database from 2012 through 2014 were identified using a validated International Classification of Diseases 9th Revision, Clinical Modification code 995.92. The primary outcome was the incidence of cardiovascular events during the hospitalizations, defined as a composite of ischemic, acute heart failure, or arrhythmic events and the secondary outcome was in-hospital mortality. Multivariable logistic regression models were used to compare the risk of in-hospital mortality among severe sepsis patients with and without cardiovascular events. A total of 117,418 patients (mean age, 70.8 years; 50.4% males, 59.5% whites) with severe sepsis occurred during the study period 2012 to 2014. New-onset (incident) cardiovascular event occurred in 13.1%, ischemic events in 4.5%, acute heart failure events in 2.3%, and arrhythmic events in 8.0% of patients, respectively. An estimated 32.9% of patients with severe sepsis died during their hospitalization. Severe sepsis patients with new-onset cardiovascular events were associated with 30% higher odds for in-hospital mortality (odds ratio: 1.30; 95% CI: 1.23 to 1.37, p < 0.001) as compared with patients without cardiovascular events in multivariable adjusted model. In conclusion, among patients with severe sepsis, incident cardiovascular events occur frequently. Further research is required to improve recognition and treatment of new-onset cardiovascular events in patients with severe sepsis.

What is cold-related mortality? A multi-disciplinary perspective to inform climate change impact assessments

BACKGROUND

There is a growing discussion regarding the mortality burdens of hot and cold weather and how the balance between these may alter as a result of climate change. Net effects of climate change are often presented, and in some settings these may suggest that reductions in cold-related mortality will outweigh increases in heat-related mortality. However, key to these discussions is that the magnitude of temperature-related mortality is wholly sensitive to the placement of the temperature threshold above or below which effects are modelled. For cold exposure especially, where threshold effects are often ill-defined, choices in threshold placement have varied widely between published studies, even within the same location. Despite this, there is little discussion around appropriate threshold selection and whether reported associations reflect true causal relationships - i.e. whether all deaths occurring below a given temperature threshold can be regarded as cold-related and are therefore likely to decrease as climate warms.

OBJECTIVES

Our objectives are to initiate a discussion around the importance of threshold placement and examine evidence for causality across the full range of temperatures used to quantify cold-related mortality. We examine whether understanding causal mechanisms can inform threshold selection, the interpretation of current and future cold-related health burdens and their use in policy formation.

METHODS

Using Greater London data as an example, we first illustrate the sensitivity of cold related mortality to threshold selection. Using the Bradford Hill criteria as a framework, we then integrate knowledge and evidence from multiple disciplines and areas- including animal and human physiology, epidemiology, biomarker studies and population level studies. This allows for discussion of several possible direct and indirect causal mechanisms operating across the range of 'cold' temperatures and lag periods used in health impact studies, and whether this in turn can inform appropriate threshold placement.

RESULTS

Evidence from a range of disciplines appears to support a causal relationship for cold across a range of temperatures and lag periods, although there is more consistent evidence for a causal effect at more extreme temperatures. It is plausible that 'direct' mechanisms for cold mortality are likely to occur at lower temperatures and 'indirect' mechanisms (e.g. via increased spread of infection) may occur at milder temperatures.

CONCLUSIONS

Separating the effects of 'extreme' and 'moderate' cold (e.g. temperatures between approximately 8-9 °C and 18 °C in the UK) could help the interpretation of studies quoting attributable mortality burdens. However there remains the general dilemma of whether it is better to use a lower cold threshold below which we are more certain of a causal relationship, but at the risk of under-estimating deaths attributable to cold.

Sepsis is a preventable public health problem

There is a paradigm shift happening for sepsis. Sepsis is no longer solely conceptualized as problem of individual patients treated in emergency departments and intensive care units but also as one that is addressed as public health issue with population- and systems-based solutions. We offer a conceptual framework for sepsis as a public health problem by adapting the traditional model of primary, secondary, and tertiary prevention.

Protracted immune disorders at one year after ICU discharge in patients with septic shock

Background

Sepsis is a leading cause of mortality and critical illness worldwide and is associated with an increased mortality rate in the months following hospital discharge. The occurrence of persistent or new organ dysfunction(s) after septic shock raises questions about the mechanisms involved in the post-sepsis status. The present study aimed to explore the immune profiles of patients one year after being discharged from the intensive care unit (ICU) following treatment for abdominal septic shock.

Methods

We conducted a prospective, single-center, observational study in the surgical ICU of a university hospital. Eighty-six consecutive patients admitted for septic shock of abdominal origin were included in this study. Fifteen different plasma biomarkers were measured at ICU admission, at ICU discharge and at one year after ICU discharge. Three different clusters of biomarkers were distinguished according to their functions, namely: (1) inflammatory response, (2) cell damage and apoptosis, (3) immunosuppression and resolution of inflammation. The primary objective was to characterize variations in the immune status of septic shock patients admitted to ICU up to one year after ICU discharge. The secondary objective was to evaluate the relationship between these biomarker variations and patient outcomes.

Results

At the onset of septic shock, we observed a cohesive pro-inflammatory profile and low levels of inflammation resolution markers. At ICU discharge, the immune status demonstrated decreased but persistent inflammation and increased immunosuppression, with elevated programmed cell death protein-1 (PD-1) levels, and a counterbalanced resolution process, with elevated levels of interleukin-10 (IL-10), resolvin D5 (RvD5), and IL-7. One year after hospital discharge, homeostasis was not completely restored with several markers of inflammation remaining elevated. Remarkably, IL-7 was persistently elevated, with levels comparable to those observed after ICU discharge, and PD-1, while lower, remained in the elevated abnormal range.

Conclusions

In this study, protracted immune disturbances were observed one year after ICU discharge. The study results suggested the presence of long-lasting immune illness disorders following a long-term septic insult, indicating the need for long-term patient follow up after ICU discharge and questioning the use of immune intervention to restore immune homeostasis after abdominal septic shock.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1934-4) contains supplementary material, which is available to authorized users.

Comparison of cardiovascular outcomes and all-cause mortality in patients with chronic hepatitis B and C: A 13-year nationwide population-based study in Asia

BACKGROUND AND AIMS

Viral hepatitis infection has been linked to increased atherosclerosis. We therefore investigated cardiovascular outcomes in patients with hepatitis B virus (HBV) and hepatitis C virus (HCV) infection.

METHODS

Electronic medical records during 2000-2012 were retrieved from the Taiwan National Health Insurance Research Database. Exclusion criteria were age <18, history of coexisting HBV and HCV infection, acute coronary syndrome, coronary intervention, venous thromboembolism, peripheral artery disease, stroke, major or gastrointestinal bleeding, malignancy, and a follow-up period <180 days. Patients with HBV and HCV infection were propensity-matched then compared for outcomes. Primary outcomes were cardiovascular events at the 1-year follow-up, 3-year follow-up, 5-year follow-up, and at the end of follow-up.

RESULTS

41,554 patients with diagnosis of HBV or HCV were retrieved from 2000 to 2012. After exclusion criteria, 31,943 patients were eligible for analysis and propensity score matched. The study population consisted of 6030 patients with HBV infection and 6030 patients with HCV infection. Risk of composite arterial events (acute coronary syndrome, peripheral artery disease, and acute ischemic stroke) was significantly higher in patients with HCV infection compared with patients with HBV infection (p = 0.012 at 5-year follow-up and p = 0.003 at the end of follow-up). All-cause mortality was significantly higher in patients with HCV infection compared with patients with HBV infection (p < 0.001 at 3-year follow-up, 5-year follow-up, and at the end of follow-up).

CONCLUSIONS

In patients with chronic viral hepatitis, subjects with HCV infection had a significantly higher risk of composite arterial events and all-cause mortality compared with those with HBV infection.