Utilization of echocardiography during septic shock was associated with a decreased 28-day mortality: a propensity score-matched analysis of the MIMIC-III database

Effectiveness of β-blockers in improving 28-day mortality in septic shock: insights from subgroup analysis and retrospective observational study

Background

In recent years, septic shock remains a common fatal disease in the intensive care unit (ICU). After sufficient fluid resuscitation, some patients still experience tachycardia, which may lead to adverse effects on cardiac function. However, the use of β-blockers in the treatment of septic shock remains controversial. Thus, the purpose of this study is to evaluate the efficacy of β-blockers in the treatment of patients with septic shock and explore the most appropriate patient subgroups for this treatment.

Methods

This retrospective observational study enrolled septic shock patients from the Medical Information Mart for Intensive Care (MIMIC)-IV and used propensity score matching (PSM) to balance some baseline differences between patients with and without β-blockers treatment. The primary outcome was the 28-day mortality. Length of stay (LOS) in the ICU and hospital, and the degree of support for organs such as circulatory, respiratory and renal systems were also assessed. Subgroup analysis and multivariate logistic regression were performed to determine the relationship between β-blockers therapy and 28-day mortality in different patient groups.

Results

A total of 4,860 septic shock patients were enrolled in this study and 619 pairs were finally matched after PSM. Our analysis revealed that β-blocker therapy was associated with a significant improvement in 28-day mortality (21.5% vs. 27.1%; P = 0.020) and led to a prolonged LOS in both the ICU and hospital. Subgroup analysis indicated that there was an interaction between cardiovascular diseases and β-blocker therapy in patients with septic shock. Patients with pre-existing heart disease or atrial arrhythmias were more likely to derive benefits from β-blocker treatment.

Conclusion

We found β-blockers therapy was effective to improve 28-day mortality in patients with septic shock. Patients in the subgroup with cardiovascular diseases were more likely to benefit from β-blockers in mortality.

Echocardiography Does not Reduce Mortality in Sepsis: A Re-Evaluation Using the Medical Information Mart for Intensive Care IV Dataset

OBJECTIVES

Echocardiography is commonly used for hemodynamic assessment in sepsis, but data regarding its association with outcome are conflicting. The aim of this study was to evaluate the association between echocardiography and outcomes in patients with septic shock using the Medical Information Mart for Intensive Care IV database.

DESIGN

Retrospective cohort study comparing patients who did or did not undergo transthoracic echocardiography within the first 5 days of admission for the primary outcome of 28-day mortality.

SETTING

Admissions to the Beth Israel Deaconess Medical Center intensive care from 2008 to 2019.

PATIENTS

Adults 16 years old or older with septic shock requiring vasopressor support within 48 hours of admission. Readmissions and patients admitted to the coronary care unit or cardiovascular intensive care were excluded, as well as patients with ST-elevation myocardial infarction or cardiac arrest.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Echocardiography was performed in 1,515 (27%) of 5,697 eligible admissions. The primary outcome was analyzed using a marginal structural model and rolling entry matching to adjust for baseline and time-varying confounders. Patients who underwent echocardiography showed no significant difference in 28-day mortality (adjusted hazard ratio 1.09; 95% CI, 0.95-1.25; p = 0.24). This was consistent across multiple sensitivity analyses. Secondary outcomes were changes in management instituted within 4 hours of imaging. Treatment changes occurred in 493 patients (33%) compared with 431 matched controls (29%), with the most common intervention being the administration of a fluid bolus.

CONCLUSIONS

Echocardiography in sepsis was not associated with a reduction in 28-day mortality based on observational data. These findings do not negate the utility of echo in cases of diagnostic uncertainty or inadequate response to initial treatment.

Association of serum phosphate and changes in serum phosphate with 28-day mortality in septic shock from MIMIC-IV database

This study aimed to investigate the relationship between serum phosphate levels, changes in serum phosphate levels, and 28-day mortality in patients with septic shock. In this retrospective study, data were collected from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database between 2008 and 2019. Patients were divided into three groups according to the tertiles of serum phosphate levels. Kaplan-Meier curves and log-rank test analyses were used for survival analysis. Multivariate logistic regression, and restricted cubic spline (RCS) curve were used to explore the association between serum phosphate, delta serum phosphate levels and 28-day mortality. In total, 3296 patients with septic shock were included in the study, and the 28-day mortality was 30.0%. Serum phosphate levels were significantly higher in the non-survivor group than in the survivor group. The Kaplan-Meier curves showed significant differences among the three groups. Multivariate logistic regression analysis and the RCS curve showed that serum phosphate levels were independently and positively associated with the 28-day mortality of septic shock. Non-survivors had higher delta serum phosphate levels than survivors. Survival analysis showed that patients with higher delta serum phosphate levels had higher 28-day mortality. A non-linear relationship was detected between delta serum phosphate and 28-day mortality with a point of inflection at - 0.3 mg/dL. Serum phosphate levels were positively and independently associated with 28-day mortality in septic shock. Delta serum phosphate level was a high-risk factor for patients with septic shock.

Role of toll-like receptor-mediated pyroptosis in sepsis-induced cardiomyopathy

Sepsis, a life-threatening dysregulated status of the host response to infection, can cause multiorgan dysfunction and mortality. Sepsis places a heavy burden on the cardiovascular system due to the pathological imbalance of hyperinflammation and immune suppression. Myocardial injury and cardiac dysfunction caused by the aberrant host responses to pathogens can lead to cardiomyopathy, one of the most critical complications of sepsis. However, many questions about the specific mechanisms and characteristics of this complication remain to be answered. The causes of sepsis-induced cardiac dysfunction include abnormal cardiac perfusion, myocardial inhibitory substances, autonomic dysfunction, mitochondrial dysfunction, and calcium homeostasis dysregulation. The fight between the host and pathogens acts as the trigger for sepsis-induced cardiomyopathy. Pyroptosis, a form of programmed cell death, plays a critical role in the progress of sepsis. Toll-like receptors (TLRs) act as pattern recognition receptors and participate in innate immune pathways that recognize damage-associated molecular patterns as well as pathogen-associated molecular patterns to mediate pyroptosis. Notably, pyroptosis is tightly associated with cardiac dysfunction in sepsis and septic shock. In line with these observations, induction of TLR-mediated pyroptosis may be a promising therapeutic approach to treat sepsis-induced cardiomyopathy. This review focuses on the potential roles of TLR-mediated pyroptosis in sepsis-induced cardiomyopathy, to shed light on this promising therapeutic approach, thus helping to prevent and control septic shock caused by cardiovascular disorders and improve the prognosis of sepsis patients.

The effect of myocardial dysfunction on mortality in children with septic shock: a prospective observational study

Pediatric septic shock is defined as progressive multi-organ dysfunction and cardiovascular dysfunction accompanying sepsis. Studies showing myocardial dysfunction associated with pediatric septic shock are very limited. The aim of this study was to evaluate the relationship between myocardial functions calculated by echocardiography, disease severity, and clinical outcomes in children with septic shock. This observational prospective study was conducted in a pediatric intensive care at a university-affiliated tertiary hospital. The patients diagnosed with septic shock between January 2021 and February 2022 were included in the study. The study was conducted with 56 patients. The rate of myocardial dysfunction (systolic and/or diastolic dysfunction) was 50%. Of these, 39.3% (n = 22) had systolic dysfunction, 17.9% (n = 10) had diastolic dysfunction, and 8.9% (n = 5) had both systolic and diastolic dysfunction. PRISM III score (p = 0.004), VIS (p < 0.001), lactate (p = 0.002), CK-MB (p = 0.023), troponin (p = 0.038), EF (p = 0.004) EF z-score (p = 0.003), MAPSE z-score (p = 0.049), TAPSE (p = 0.010), TAPSE z-score (p = 0.003), and mitral valve E/e ´z-score (p = 0.028) were statistically significant difference with mortality. No significant difference was found for mortality with MAPSE (p = 0.090), mitral valve E/A (p = 0.624), and mitral valve E/A z-score (p = 0.327). EF z-score was found to be associated with 30-day mortality (OR = 0,681, 95% CI 0,480 to 0.991, p = 0,045). We found the TAPSE z-score to be the most significant parameter with 30-day mortality (OR = 0,690, 95% CI 0,489 to 0.998, p = 0,032).  Conclusion: We found left ventricular dysfunction associated factor with mortality. TAPSE showing right ventricular dysfunction was found to be the independent risk factor most associated with mortality. What is Known: • Studies showing myocardial dysfunction associated with pediatric septic shock are limited. • Little is known about the use of echocardiography in pediatric septic shock, and there are no specific guidelines for treatment and follow-up in pediatric patients. What is New: • Characteristics, echocardiographic measurements, and outcomes were comprehensively assessed in children with septic shock. • As a result of our analysis, we found that TAPSE, which is easily measured at the bedside, is the most critical parameter in relation to mortality. • We offer recommendations for its use in the follow-up of children with septic shock.

Effect of β-blockers on mortality in patients with sepsis: A propensity-score matched analysis

Objectives

We aimed to evaluate the association between β-blocker therapy and mortality in patients with sepsis.

Methods

Patients with sepsis were selected from the Medical Information Mart for Intensive Care (MIMIC)-III. Propensity score matching (PSM) was used to balance the baseline differences. A multivariate Cox regression model was used to assess the relationship between β-blocker therapy and mortality. The primary outcome was the 28-day mortality.

Results

A total of 12,360 patients were included in the study, involving 3,895 who received β-blocker therapy and 8,465 who did not. After PSM, 3,891 pairs of patients were matched. The results showed that β-blockers were associated with improved 28- (hazards ratio (HR) 0.78) and 90-day (HR 0.84) mortality. Long-acting β-blockers were associated with improved 28-day survival (757/3627 [20.9%] vs. 583/3627 [16.1%], P &lt; 0.001, HR0.76) and 90-day survival (1065/3627 [29.4%] vs.921/3627 [25.4%], P &lt; 0.001, HR 0.77). Short-acting β-blocker treatment did not reduce the 28-day and 90-day mortality (61/264 [23.1%] vs. 63/264 [23.9%], P = 0.89 and 83/264 [31.4%] vs. 89/264 [31.7%], P = 0.8, respectively).

Conclusions

β-blockers were associated with improved 28- and 90-day mortality in patients with sepsis and septic shock. Long-acting β-blocker therapy may have a protective role in patients with sepsis, reducing the 28-day and 90-day mortality. However, short-acting β-blocker (esmolol) treatment did not reduce the mortality in sepsis.

Data processing pipeline for cardiogenic shock prediction using machine learning

Introduction

Recent advances in machine learning provide new possibilities to process and analyse observational patient data to predict patient outcomes. In this paper, we introduce a data processing pipeline for cardiogenic shock (CS) prediction from the MIMIC III database of intensive cardiac care unit patients with acute coronary syndrome. The ability to identify high-risk patients could possibly allow taking pre-emptive measures and thus prevent the development of CS.

Methods

We mainly focus on techniques for the imputation of missing data by generating a pipeline for imputation and comparing the performance of various multivariate imputation algorithms, including k-nearest neighbours, two singular value decomposition (SVD)-based methods, and Multiple Imputation by Chained Equations. After imputation, we select the final subjects and variables from the imputed dataset and showcase the performance of the gradient-boosted framework that uses a tree-based classifier for cardiogenic shock prediction.

Results

We achieved good classification performance thanks to data cleaning and imputation (cross-validated mean area under the curve 0.805) without hyperparameter optimization.

Conclusion

We believe our pre-processing pipeline would prove helpful also for other classification and regression experiments.

Association between Wait Time for Transthoracic Echocardiography and 28-Day Mortality in Patients with Septic Shock: A Cohort Study

Background: the optimal timing of Transthoracic echocardiography (TTE) performance for patients with septic shock remains unexplored. Methods: a retrospective cohort study included patients with septic shock in the MIMIC-Ⅲ database. Risk-adjusted restricted cubic splines modeled the 28-day mortality according to time elapsed from ICU admission to receive TTE. The cut point when a smooth curve inflected was selected to define early and delayed group. We applied propensity score matching (PSM) to ensure our findings were reliable. Causal mediation analysis was used to assess the intermediate effect of fluid balance within 72 h after ICU admission. Results: 3264 participants were enrolled and the risk of 28-day mortality increased until the wait time was around 10 h (Early group) and then was relatively flat afterwards (Delayed group). A beneficial effect of early TTE in terms of the 28-day mortality was observed (HRs 0.73−0.78, all p < 0.05) in the PSM. The indirect effect brought by the fluid balance on day 2 and 3 was significant (both p = 0.006). Conclusion: early TTE performance might be associated with lower risk-adjusted 28-day mortality in patients with septic shock. Better fluid balance may have mediated this effect. A wait time within 10 h after ICU may represent a threshold defining progressively increasing risk.

The Effect of Sepsis on Myocardial Function: A Review of Pathophysiology, Diagnostic Criteria, and Treatment

Sepsis remains a worldwide challenge for physicians with many patients admitted to ICUs with septic shock. Septic shock management involves targeted treatment to control infections, reduce end-organ damage, and reverse the injury. Sepsis-induced myocardial dysfunction or septic cardiomyopathy remains an avenue to be explored with regard to underlying pathophysiology and definite treatment guidelines. This article has compiled various studies to explain the possible mechanisms involved in the development of septic cardiomyopathy and the existing diagnostic criteria including radiological and laboratory tests to assess septic cardiomyopathy. Furthermore, the article highlights management options currently available for physicians dealing with myocardial dysfunction secondary to sepsis.

Cardiotoxicity from chimeric antigen receptor-T cell therapy for advanced malignancies

Chimeric antigen receptor (CAR)-T cell therapy is the next revolutionary advance in cancer therapy. By using ex vivo engineered T cells to specifically target antigens, a targeted immune reaction is induced. Chimeric antigen receptor-T cell therapy is approved for patients suffering from advanced and refractory B cell and plasma cell malignancies and is undergoing testing for various other haematologic and solid malignancies. In the process of triggering an anticancer immune reaction, a systemic inflammatory response can emerge as cytokine release syndrome (CRS). The severity of CRS is highly variable across patients, ranging from mild flu-like symptoms to fulminant hyperinflammatory states with excessive immune activation, associated multiorgan failure and high mortality risk. Cytokine release syndrome is also an important factor for adverse cardiovascular (CV) events. Sinus tachycardia and hypotension are the most common reflections, similar to what is seen with other systemic inflammatory response syndromes. Corrected QT interval prolongation and tachyarrhythmias, including ventricular arrhythmias and atrial fibrillation, also show a close link with CRS. Events of myocardial ischaemia and venous thromboembolism can be provoked during CAR-T cell therapy. Although not as closely related to CRS, changes in cardiac function can be observed to the point of heart failure and cardiogenic shock. This may also be encountered in patients with severe valvular heart disease in the setting of CRS. This review will discuss the pertinent CV risks of the growing field of CAR-T cell therapy for today's cardiologists, including incidence, characteristics, and treatment options, and will conclude with an integrated management algorithm.

Association between albumin infusion and outcomes in patients with acute kidney injury and septic shock

Septic shock with acute kidney injury (AKI) is common in critically ill patients. Our aim was to evaluate the association between albumin infusion and outcomes in patients with septic shock and AKI. Medical Information Mart for Intensive Care (MIMIC)-III was used to identify patients with septic shock and AKI. Propensity score matching (PSM) was employed to balance the baseline differences. Cox proportional hazards model, Wilcoxon rank-sum test, and logistic regression were utilized to determine the associations of albumin infusion with mortality, length of stay, and recovery of kidney function, respectively. A total of 2861 septic shock patients with AKI were studied, including 891 with albumin infusion, and 1970 without albumin infusion. After PSM, 749 pairs of patients were matched. Albumin infusion was associated with improved 28-day survival (HR 0.72; 95% CI 0.59–0.86; P = 0.002), but it was not difference in 90-day mortality between groups (HR 0.94; 95% CI 0.79–1.12; P = 0.474). Albumin infusion was not associated with the renal function recovery (HR 0.91; 95% CI 0.73–1.13; P = 0.393) in either population. Nevertheless, subgroup analysis showed that albumin infusion was distinctly associated with reduced 28-day mortality in patients with age > 60 years. The results need to be validated in more randomized controlled trials.

Integrated Multiorgan Bedside Ultrasound for the Diagnosis and Management of Sepsis and Septic Shock

Despite decades of research, the mortality rate of sepsis and septic shock remains unacceptably high. Delays in diagnosis, identification of an infectious source, and the challenge of providing patient-tailored resuscitation measures routinely result in suboptimal patient outcomes. Bedside ultrasound improves a clinician's ability to both diagnose and manage the patient with sepsis. Indeed, multiple point-of-care ultrasound (POCUS) protocols have been developed to evaluate and treat various subsets of critically ill patients. These protocols mostly target patients with undifferentiated shock and have been shown to improve clinical outcomes. Other studies have shown that POCUS can improve a clinician's ability to identify a source of infection. Once a diagnosis of septic shock has been made, serial POCUS exams can be used to continuously guide resuscitative efforts. In this review, we advocate that the patient with suspected sepsis or septic shock undergo a comprehensive POCUS exam in which sonographic information across organ systems is synthesized and used in conjunction with traditional data gleaned from the patient's history, physical exam, and laboratory studies. This harmonization of information will hasten an accurate diagnosis and assist with hemodynamic management.

Utilization of Echocardiography After Acute Kidney Injury Was Associated with Improved Outcomes in Patients in Intensive Care Unit

Background

We aimed to investigate the association between usage of transthoracic echocardiography (TTE) within 24 hours after acute kidney injury (AKI) and the prognosis of patients in intensive care unit (ICU).

Methods

The Medical Information Mart for Intensive Care III (MIMIC-III) database was used to identify AKI patients with and without TTE administration. The primary outcome was 28-day mortality. Multivariable regression was used to clarify the association between TTE and clinical outcomes and propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were utilized to validate our findings.

Results

Among 23,945 eligible AKI patients, 3361 patients who received TTE and 3361 who did not conduct TTE had similar propensity scores which were included in this study. After matching, the TTE group had a significantly lower 28-day mortality (OR 0.80, 95% CI 0.72–0.88, P<0.001). Patients in the TTE group received more fluid on day 1 and day 2 and had a more urine volume on day 1 and day 3, and the reduction in serum creatinine was greater than that in the no TTE group. The mediating effect of creatinine reduction was remarkable for the whole cohort (P=0.02 for the average causal mediation effect).

Conclusion

TTE utilization was associated with decreased risk-adjusted 28-day mortality for AKI patients in ICU and was proportionally mediated through creatinine reduction.

Propensity score matching with R: conventional methods and new features

It is increasingly important to accurately and comprehensively estimate the effects of particular clinical treatments. Although randomization is the current gold standard, randomized controlled trials (RCTs) are often limited in practice due to ethical and cost issues. Observational studies have also attracted a great deal of attention as, quite often, large historical datasets are available for these kinds of studies. However, observational studies also have their drawbacks, mainly including the systematic differences in baseline covariates, which relate to outcomes between treatment and control groups that can potentially bias results. Propensity score methods, which are a series of balancing methods in these studies, have become increasingly popular by virtue of the two major advantages of dimension reduction and design separation. Within this approach, propensity score matching (PSM) has been empirically proven, with outstanding performances across observational datasets. While PSM tutorials are available in the literature, there is still room for improvement. Some PSM tutorials provide step-by-step guidance, but only one or two packages have been covered, thereby limiting their scope and practicality. Several articles and books have expounded upon propensity scores in detail, exploring statistical principles and theories; however, the lack of explanations on function usage in programming language has made it difficult for researchers to understand and follow these materials. To this end, this tutorial was developed with a six-step PSM framework, in which we summarize the recent updates and provide step-by-step guidance to the R programming language. This tutorial offers researchers with a broad survey of PSM, ranging from data preprocessing to estimations of propensity scores, and from matching to analyses. We also explain generalized propensity scoring for multiple or continuous treatments, as well as time-dependent PSM. Lastly, we discuss the advantages and disadvantages of propensity score methods.