Severity of cardiac impairment in the early stage of community-acquired sepsis determines worse prognosis

Septic cardiomyopathy phenotype in the critically ill may depend on antimicrobial resistance

Background

Sepsis is a life-threatening organ dysfunction, and septic cardiomyopathy (SCM) may complicate the course of the disease. Infection with multidrug-resistant (MDR) pathogens has been linked with worse outcomes. This study aims to evaluate SCM in patients with infections caused by different antimicrobial-resistant phenotypes.

Method

This retrospective study included patients with sepsis/septic shock, hospitalized, and intubated in the intensive care unit of the University Hospital of Larissa between January 2022 and September 2023 with echocardiographic data during the first two days after infection onset. The patients were divided into two groups: non-MDR-SCM group and MDR-SCM group. The cardiac function was compared between the two groups.

Result

A total of 62 patients were included in the study. Forty-four patients comprised the MDR-SCM and 18 the non-MDR-SCM group. Twenty-six patients (41.9%) presented with left ventricular (LV) systolic dysfunction, and ≤35% right ventricular fractional area change (RVFAC) was present in 56.4%. LV systolic function was more severely impaired in the non-MDR-SCM group (left ventricular ejection fraction, 35.8% ±4.9% vs. 45.6%±2.4%, P=0.049; LV outflow tract velocity time integral, [10.1±1.4] cm vs. [15.3±0.74] cm, P=0.001; LV-Strain, -9.02%±0.9% vs. -14.02%±0.7%, P=0.001). The MDR-SCM group presented with more severe right ventricular (RV) dilatation (right ventricular end-diastolic area/left ventricular end-diastolic area, 0.81±0.03 vs. 0.7±0.05, P=0.042) and worse RV systolic function (RVFAC, 32.3%±1.9% vs. 39.6%±2.7%, P=0.035; tricuspid annular plane systolic excursion, [15.9±0.9] mm vs. [18.1±0.9] mm, P=0.165; systolic tissue Doppler velocity measured at the lateral tricuspid annulus, [9.9±0.5] cm/s vs. [13.1±0.8] cm/s, P=0.002; RV-strain, -11.1%±0.7% vs. -15.1%±0.9%, P=0.002).

Conclusion

SCM related to MDR infection presents with RV systolic dysfunction predominance, while non-MDR-SCM is mainly depicted with LV systolic dysfunction impairment.

A novel speckle-tracking echocardiography parameter assessing left ventricular afterload

BACKGROUND

Left ventricular stroke work index (LVSWI) and afterload-related cardiac performance (ACP) consider left ventricular (LV) afterload and could be better prognosticators in septic cardiomyopathy. However, their invasive nature prevents their routine clinical applications. This study aimed to investigate (1) whether a proposed speckle-tracking echocardiography parameter, Pressure-Strain Product (PSP), can non-invasively predict catheter-based LVSWI, ACP and serum lactate in an ovine model of septic cardiomyopathy; and (2) whether PSP can distinguish the sub-phenotypes of acute respiratory distress syndrome (ARDS) with or without sepsis-like conditions.

METHODS

Sixteen sheep with ARDS were randomly assigned to either (1) sepsis-like (n = 8) or (2) non-sepsis-like (n = 8) group. Each ARDS and sepsis-like condition was induced by intravenous infusion of oleic acid and lipopolysaccharide, respectively. Pulmonary artery catheter-based LVSWI (the product of stroke work index, mean arterial pressure and .0136), ACP (the percentage of cardiac output measured to cardiac output predicted as normal) and serum lactate were measured simultaneously with transthoracic echocardiography. Two PSP indices were calculated by multiplying the mean arterial blood pressure and either global circumferential strain (PSPcirc) or radial strain (PSPrad).

RESULTS

PSPcirc showed a significant correlation with LVSWI (r2  = .66, p < .001) and ACP (r2  = .82, p < .001) in the sepsis-like group. Although PSP could not distinguish subphenotypes, PSPcirc predicted LVSWI (AUC .86) and ACP (AUC .88), and PSPrad predicted serum lactate (AUC .75) better than LV ejection fraction, global circumferential and radial strain.

CONCLUSIONS

A novel PSP has the potential to non-invasively predict catheter-based LVSWI and ACP, and was associated with serum lactate in septic cardiomyopathy.

Research Progress on the Mechanism and Management of Septic Cardiomyopathy: A Comprehensive Review

Sepsis is defined as a kind of life-threatening organ dysfunction due to a dysregulated host immune response to infection and is a leading cause of mortality in the intensive care unit. Sepsis-induced myocardial dysfunction, also called septic cardiomyopathy, is a common and serious complication in patients with sepsis, which may indicate a bad prognosis. Although efforts have been made to uncover the pathophysiology of septic cardiomyopathy, a number of uncertainties remain. This article sought to review available literature to summarize the existing knowledge on current diagnostic tools and biomarkers, pathogenesis, and treatments for septic cardiomyopathy.

Levosimendan in the Treatment of Patients with Severe Septic Cardiomyopathy

(1) Background: The optimal treatment of septic cardiomyopathy (SCM) remains questionable. The aim of the study was to compare the treatment of SCM based on levosimendan versus the best available therapy. (2) Methods: We conducted an observational study including patients with severe septic cardiomyopathy and circulatory failure. (3) Results: Fourteen patients (61%) received levosimendan, and nine received other treatments. The patients in the levosimendan group were more severely ill [APACHE II: 23.5 (14, 37) vs. 14 (13, 28), respectively, p = 0.012], and there was a trend for more decompensated LV function depicted by the LVEF [15% (10, 20) vs. 25% (5, 30), respectively, p = 0.061]. However, they presented a significantly higher increase in LVEF after seven days [15% (10, 20) to 50% (30, 68) (p < 0.0001) vs. 25% (5, 30) to 25% (15, 50) (p = 0.309), and a significantly higher decrease in lactate levels during the first 24 h [4.5 (2.5, 14.4) to 2.85 (1.2, 15), p = 0.036 vs. 2.9 (2, 18.9) to 2.8 (1, 15), p = 0.536]. Seven-day survival (64.3% vs. 33.3%, p = 0.424) and ICU survival (50% vs. 22.2%, p = 0.172) were higher in the first group, although differences did not reach statistical significance. The degree of left ventricular impairment and the magnitude of EF improvement by the seventh-day post-SCM onset were associated with mortality in regression analysis. (4) Conclusions: Our study presents main hemodynamic data supporting the possible efficacy of levosimendan treatment in patients with severe SCM.

Afterload-related cardiac performance is a powerful hemodynamic predictor of mortality in patients with chronic heart failure

Background

Afterload-related cardiac performance (ACP), a diagnostic parameter for septic cardiomyopathy, integrates both cardiac performance and vascular effects and could predict prognosis in septic shock.

Objectives

We hypothesized that ACP would also correlate with clinical outcomes in patients with chronic heart failure (HF).

Design

A retrospective study.

Methods

We retrospectively studied consecutive patients with chronic HF who underwent right heart catheterization and established an expected cardiac output-systemic vascular resistance (CO-SVR) curve model in chronic HF for the first time. ACP was calculated as COmeasured/COpredicted × 100%. ACP > 80%, 60% < ACP ⩽ 80%, and ACP ⩽ 60% represented less impaired, mildly impaired, and severely impaired cardiovascular function, respectively. The primary outcome was all-cause mortality, and the secondary outcome was event-free survival.

Results

A total of 965 individual measurements from 290 eligible patients were used to establish the expected CO-SVR curve model (COpredicted = 53.468 × SVR -0.799). Patients with ACP ⩽ 60% had higher serum NT-proBNP levels (P < 0.001), lower left ventricular ejection fraction (P = 0.001), and required dopamine more frequently (P < 0.001). Complete follow-up data were available in 263 of 290 patients (90.7%). After multivariate adjustment, ACP remained associated with both primary outcome (hazard ratio (HR) 0.956, 95% confidence interval (CI) 0.927-0.987) and secondary outcome (HR 0.977, 95% CI 0.963-0.992). Patients with ACP ⩽ 60% had the worst prognosis (all P < 0.001). ACP was significantly more discriminating (area under the curve of 0.770) than other conventional hemodynamic parameters in predicting mortality (Delong test, all P < 0.05).

Conclusion

ACP is a powerful independent hemodynamic predictor of mortality in patients with chronic HF. ACP and the novel CO-SVR two-dimensional graph could be useful in assessing cardiovascular function and making clinical decisions.

Clinical trial registration

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02664818.

ANXA1sp Protects against Sepsis-Induced Myocardial Injury by Inhibiting Ferroptosis-Induced Cardiomyocyte Death via SIRT3-Mediated p53 Deacetylation

Sepsis-induced myocardial injury (SIMI), a common complication of sepsis, may cause significant mortality. Ferroptosis, a cell death associated with oxidative stress and inflammation, has been identified to be involved in SIMI. This study sought to investigate the role of ANXA1 small peptide (ANXA1sp) in SIMI pathogenesis. In this study, the mouse cardiomyocytes (H9C2 cells) were stimulated with lipopolysaccharide (LPS) to imitate SIMI in vitro. It was shown that ANXA1sp treatment substantially abated LPS-triggered H9C2 cell death and excessive secretion of proinflammatory cytokines (TNF-α, IL-1β, and IL-6). ANXA1sp pretreatment also reversed the increase of ROS and MDA generation as well as the decrease of SOD and GSH activity in H9C2 cells caused by LPS treatment. In addition, ANXA1sp considerably eliminated LPS-caused H9C2 cell ferroptosis, as revealed by the suppression of iron accumulation and the increase in GPX4 and FTH1 expression. Furthermore, the ameliorative effects of ANXA1sp on LPS-induced H9C2 cell damage could be partially abolished by erastin, a ferroptosis agonist. ANXA1sp enhanced SIRT3 expression in LPS-challenged H9C2 cells, thereby promoting p53 deacetylation. SIRT3 knockdown diminished ANXA1sp-mediated alleviation of cell death, inflammation, oxidative stress, and ferroptosis of LPS-treated H9C2 cells. Our study demonstrated that ANXA1sp is protected against LPS-induced cardiomyocyte damage by inhibiting ferroptosis-induced cell death via SIRT3-dependent p53 deacetylation, suggesting that ANXA1sp may be a potent therapeutic agent for SIMI.

The Chronological Demographics of Ventricular-Arterial Decoupling in Patients with Sepsis and Septic Shock: A Prospective Observational Study

BACKGROUND

Ventricular-arterial coupling (V-A coupling) recently gathers attention from clinicians to evaluate the interaction between afterload and left ventricular systolic function. We aimed to describe the chronological demographics of V-A decoupling in patients with sepsis and septic shock through the clinical course.

METHOD

We conducted a single-center prospective observational study comprising adult patients with sepsis and septic shock admitted to the tertiary care hospital between 04/2017 and 03/2019. Patients' characteristics, lab data on admission, and echocardiographic parameters including Ea and Ees on the day- 1, 2, 3, 7, and 14-28 were collected. V-A decoupling was defined as Ea/Ees ≥ 1.36.

RESULTS

Seventy-one patients with sepsis or septic shock were enrolled. The prevalence of V-A decoupling was as follows; day-1: 25.4%, day-2: 23.8%, day-3: 13.3%, day-7: 18.5%, day-14-28: 30.3%, respectively. Ea was higher in patients with V-A decoupling than those without throughout the clinical course (day1; 2.8 vs. 1.8, p < 0.01, day2; 2.7 vs. 1.9, p < 0.01, day3; 2.8 vs. 2.1, p = 0.06, day7; 2.7 vs. 1.9, p = 0.02, day14-28; 2.4 vs. 1.8, p = 0.08). This increase in Ea was mainly induced by reduced stroke volume (SV) as well as high systolic blood pressure (SBP) in the earlier course of sepsis but only by increased SBP in the later course of sepsis. Ees was lower in patients with V-A decoupling than those without throughout the clinical course (day1; 1.3 vs. 2.1, p < 0.01, day2; 1.5 vs. 2.3, p < 0.01, day3; 1.6 vs. 2.3, p = 0.02, day7; 1.8 vs. 2.3, p = 0.01, day14-28; 1.2 vs. 1.9, p = 0.07).

CONCLUSION

We reported that V-A decoupling was commonly seen in patients with sepsis and septic shock. In patients with V-A decoupling, both Ea and Ees were significantly altered, but the causes of these alterations appeared to be changing over the clinical course of sepsis.

Association of sepsis-induced cardiomyopathy and mortality: a systematic review and meta-analysis

BACKGROUND

The implication of sepsis-induced cardiomyopathy (SIC) to prognosis is controversial, and its association with mortality at different stages remains unclear. We conducted a systematic review and meta-analysis to understand the association between SIC and mortality in septic patients.

METHODS

We searched and appraised observational studies regarding the mortality related to SIC among septic patients in PubMed and Embase from inception until 8 July 2021. Outcomes comprised in-hospital and 1-month mortality. We adopted the random-effects model to examine the mortality risk ratio in patients with and without SIC. Meta-regression, subgroup, and sensitivity analyses were applied to examine the outcome's heterogeneity.

RESULTS

Our results, including 20 studies and 4,410 septic patients, demonstrated that SIC was non-statistically associated with increased in-hospital mortality, compared to non-SIC (RR 1.28, [0.96-1.71]; p = 0.09), but the association was statistically significant in patients with the hospital stay lengths longer than 10 days (RR 1.40, [1.02-1.93]; p = 0.04). Besides, SIC was significantly associated with a higher risk of 1-month mortality (RR 1.47, [1.17-1.86]; p < 0.01). Among SIC patients, right ventricular dysfunction was significantly associated with increased 1-month mortality (RR 1.72, [1.27-2.34]; p < 0.01), while left ventricular dysfunction was not (RR 1.33, [0.87-2.02]; p = 0.18).

CONCLUSIONS

With higher in-hospital mortality in those hospitalized longer than 10 days and 1-month mortality, our findings imply that SIC might continue influencing the host's system even after recovery from cardiomyopathy. Besides, right ventricular dysfunction might play a crucial role in SIC-related mortality, and timely biventricular assessment is vital in managing septic patients.

Utility of Cardiac Power Hemodynamic Measurements in the Evaluation and Risk Stratification of Cardiovascular Conditions

Despite numerous advancements in prevention, diagnosis and treatment, cardiovascular disease has remained the leading cause of mortality globally for the past 20 years. Part of the explanation for this trend is persistent difficulty in determining the severity of cardiac conditions in order to allow for the deployment of prompt therapies. This review seeks to determine the prognostic importance of cardiac power (CP) measurements, including cardiac power output (CPO) and cardiac power index (CPI), in various cardiac pathologies. CP was evaluated across respective disease-state categories which include cardiogenic shock (CS), septic shock, transcatheter aortic valve replacement (TAVR), heart failure (HF), post-myocardial infarction (MI), critical cardiac illness (CCI) and an "other" category. Literature review was undertaken of articles discussing CP in various conditions and this review found utility and prognostic significance in the evaluation of TAVR patients with a significant correlation between one-year mortality and CPI; in HF patients showing CPI and CPO as valuable tools to assess cardiac function in the acute setting; and, additionally, CPO was found to be an essential tool in patients with CCI, as the literature showed that CPO was statistically correlated with mortality. Cardiac power and the derived measures obtained from this relatively easily obtained variable can allow for essential estimations of prognostic outcomes in cardiac patients.

Septic Cardiomyopathy: From Pathophysiology to the Clinical Setting

The onset of cardiomyopathy is a common feature in sepsis, with relevant effects on its pathophysiology and clinical care. Septic cardiomyopathy is characterized by reduced left ventricular (LV) contractility eventually associated with LV dilatation with or without right ventricle failure. Unfortunately, such a wide range of ultrasonographic findings does not reflect a deep comprehension of sepsis-induced cardiomyopathy, but rather a lack of consensus about its definition. Several echocardiographic parameters intrinsically depend on loading conditions (both preload and afterload) so that it may be challenging to discriminate which is primitive and which is induced by hemodynamic perturbances. Here, we explore the state of the art in sepsis-related cardiomyopathy. We focus on the shortcomings in its definition and point out how cardiac performance dynamically changes in response to different hemodynamic clusters. A special attention is also given to update the knowledge about molecular mechanisms leading to myocardial dysfunction and that recall those of myocardial hibernation. Ultimately, the aim of this review is to highlight the unsolved issue in the field of sepsis-induced cardiomyopathy as their implementation would lead to improve risk stratification and clinical care.

Dissecting the correlates of N-terminal prohormone brain natriuretic peptide in acute infective endocarditis

Purpose

To explore the prognostic value and the correlates of NT-proBNP in patients with acute infective endocarditis, a life-threatening disease, with an often unpredictable outcome given by the lack of reliable prognostic parameters.

Methods

We retrospectively studied 337 patients admitted to our centre between January 1, 2006 and September 30, 2020 with available NT-proBNP level at admission. Our analyses were performed considering NT-proBNP as both a categorical variable, using the median value as the cut-off level, and numerical variable. Study end points were in-hospital mortality, cardiac surgery and 1 year survival.

Results

NT-proBNP was an independent predictor of in-hospital mortality (OR 14.9 [95%C.I. 2.46–90.9]; P = .003). Levels below 2926 pg/mL were highly predictive of a favorable in-hospital outcome (negative predictive value 96.6%). Patients with higher NT-proBNP levels showed a significantly lower survival rate at 1 year follow-up (log-rank P = .005). NT-proBNP was strongly associated with chronic kidney disease (P < .001) and significantly higher in patients with prior chronic heart failure (P = .001). NT-proBNP was tightly related to staphylococcal IE (P = .001) as well as with higher CRP and hs-troponin I (P = 0.023, P < .001, respectively).

Conclusion

Our results confirm the remarkable prognostic role of NT-proBNP in patients with IE and provide novel evidences of its multifaceted correlates in this unique clinical setting. Our data strongly support the incorporation of NT-proBNP into the current diagnostic work-up of IE.

Pyruvate-Driven Oxidative Phosphorylation is Downregulated in Sepsis-Induced Cardiomyopathy: A Study of Mitochondrial Proteome

BACKGROUND

Sepsis-induced cardiomyopathy (SIC) is a major contributing factor for morbidity and mortality in sepsis. Accumulative evidence has suggested that cardiac mitochondrial oxidative phosphorylation is attenuated in sepsis, but the underlying molecular mechanisms remain incompletely understood.

METHODS

Adult male mice of 9 to 12 weeks old were subjected to sham or cecal ligation and puncture procedure. Echocardiography in vivo and Langendorff-perfused hearts were used to assess cardiac function 24 h after the procedures. Unbiased proteomics analysis was performed to profile mitochondrial proteins in the hearts of both sham and SIC mice. Seahorse respirator technology was used to evaluate oxygen consumption in purified mitochondria.

RESULTS

Of the 665 mitochondrial proteins identified in the proteomics assay, 35 were altered in septic mice. The mitochondrial remodeling involved various energy metabolism pathways including subunits of the electron transport chain, fatty acid catabolism, and carbohydrate oxidative metabolism. We also identified a significant increase of pyruvate dehydrogenase (PDH) kinase 4 (PDK4) and inhibition of PDH activity in septic hearts. Furthermore, compared to sham mice, mitochondrial oxygen consumption of septic mice was significantly reduced when pyruvate was provided as a substrate. However, it was unchanged when PDH was bypassed by directly supplying the Complex I substrate NADH, or by using the Complex II substrate succinate, or using Complex IV substrate, or by providing the beta-oxidation substrate palmitoylcarnitine, neither of which require PDH for mitochondrial oxygen consumption.

CONCLUSIONS

These data demonstrate a broad mitochondrial protein remodeling, PDH inactivation and impaired pyruvate-fueled oxidative phosphorylation during SIC, and provide a molecular framework for further exploration.

COMBED: Rapid non-invasive Cardiac Output Monitoring Baseline assessment in adult Emergency Department patients with haemodynamic instability

OBJECTIVE

The application of rapid, non-operator-dependent, non-invasive cardiac output monitoring (COM) may provide early physiological information in ED patients with haemodynamic instability (HI). Our primary objective was to assess the feasibility of measuring pre-intervention (baseline) cardiac index (CI) and associated haemodynamic parameters.

METHODS

We performed a prospective observational study of adults shortly after presentation to the ED of a large university hospital with tachycardia or hypotension or both. We applied non-invasive COM for 5 min and recorded CI, mean arterial pressure (MAP), stroke volume index (SVI) and systemic vascular resistance index (SVRI). We assessed for differences between those presenting with hypotension or hypotension and tachycardia with tachycardia alone and between those with or without suspected infection.

RESULTS

We obtained haemodynamic parameters in 46 of 49 patients. In patients with hypotension or hypotension and tachycardia (n = 15) rather than tachycardia alone (n = 31), we observed a lower MAP (60.8 vs 87.7, P < 0.0001), CI (2.8 vs 3.9, P = 0.0167) and heart rate (85.5 vs 115.4, P < 0.0001). There was no difference in SVI (33.7 vs 33.4, P = 0.93) or SVRI (1970 vs 2088, P = 0.67). Patients with suspected infection had similar haemodynamic values except for a lower SVRI (1706 vs 2237, P = 0.011).

CONCLUSIONS

Rapid, non-operator-dependent, non-invasive COM was possible in >90% of ED patients presenting with HI. Compared with tachycardia alone, patients with hypotension had lower CI, MAP and heart rate, while those with suspected infection had a lower SVRI. This technology provides novel insights into the early state of the circulation in ED patients with HI.

Septic cardiomyopathy: Diagnosis and management

There is an extensive body of literature focused on sepsis-induced myocardial dysfunction, but results are conflicting and no objective definition of septic cardiomyopathy (SCM) has been established. SCM may be defined as a sepsis-associated acute syndrome of non-ischemic cardiac dysfunction with systolic and/or diastolic left ventricular (LV) dysfunction and/or right ventricular dysfunction. Physicians should consider this diagnosis in patients with sepsis-associated organ dysfunction, and particularly in cases of septic shock that require vasopressors. Echocardiography is currently the gold standard for diagnosis of SCM. Left ventricular ejection fraction is the most common parameter used to describe LV function in the literature, but its dependence on loading conditions, particularly afterload, limits its use as a measure of intrinsic myocardial contractility. Therefore, repeated echocardiography evaluation is mandatory. Evaluation of global longitudinal strain (GLS) may be more sensitive and specific for SCM than LV ejection fraction (LVEF). Standard management includes etiological treatment, adapted fluid resuscitation, use of vasopressors, and monitoring. Use of inotropes remains uncertain, and heart rate control could be an option in some patients.

Afterload-related cardiac performance predicts prognosis in critical ill patients with sepsis: A prospective observational pilot study

ABSTRACT

To investigate the usefulness of afterload-related cardiac performance (ACP) for assessing cardiac impairment and predicting prognosis in septic patients.Adult patients with sepsis in the intensive care unit were included. Cardiac output, cardiac index, cardiac power index, and ACP were calculated at the time of admission (D0) and 48-72 h after admission (D3). They were correlated with Acute Physiology and Chronic Health Evaluation II and sequential organ failure assessment scores, then the prognostic values were analyzed.A total of 41 patients with sepsis were selected. ACP showed a stronger negative correlation with Acute Physiology and Chronic Health Evaluation II and sequential organ failure assessment scores than cardiac output, cardiac index, and cardiac power index. ACP predicted 28-day mortality with an area under the curve of 0.775 and 0.976 on D0 and D3, respectively. In addition, most non-survivors had emergent cardiac impairment (ACP ≤ 80%) on D0, and cardiac function was deteriorated on D3. Survival analysis showed that the patients with a decreased ACP from D0 to D3 had the highest mortality. The decrease of ACP on D3 was an independent risk factor for mortality (hazard ratio, 11.89; P = .0028).ACP can be used to assess the severity of cardiac impairment in sepsis. Continued decline of ACP during the first 3 days strongly suggests a poor prognosis.

Effect of Heart Rate on the Outcome of Renal Denervation in Patients With Uncontrolled Hypertension

BACKGROUND

Sham-controlled trials demonstrated safety and efficacy of renal denervation (RDN) to lower blood pressure (BP). Association of baseline heart rate with BP reduction after RDN is incompletely understood.

OBJECTIVES

The purpose of this analysis was to evaluate the impact of baseline heart rate on BP reduction without antihypertensive medications in the SPYRAL HTN-OFF MED (Global Clinical Study of Renal Denervation With the Symplicity Spyral Multi-electrode Renal Denervation System in Patients With Uncontrolled Hypertension in the Absence of Antihypertensive Medications) Pivotal trial.

METHODS

Patients removed from any antihypertensive medications were enrolled with office systolic blood pressure (SBP) ≥150 and <180 mm Hg and randomized 1:1 to RDN or sham control. Patients were separated according to baseline office heart rate <70 or ≥70 beats/min. BP changes from baseline to 3 months between treatment arms were adjusted for baseline SBP using analysis of covariance.

RESULTS

Scatter plots of 3-month changes in 24-hour and office SBP illustrate a wide range of changes in SBP for different baseline heart rates. Treatment difference at 3 months between RDN and sham control with baseline office heart rate ≥70 beats/min for 24-hour SBP was -6.2 mm Hg (95% CI: -9.0 to -3.5 mm Hg) (P < 0.001) and for baseline office heart rate <70 beats/min it was -0.1 mm Hg (-3.8 to 3.6 mm Hg) (P = 0.97) with an interaction P value of 0.008. Results were similar for changes in office, daytime, and nighttime SBP at 3 months, with a greater reduction in SBP with baseline office heart rate ≥70 beats/min.

CONCLUSIONS

Reduction in mean office, 24-hour, daytime, and nighttime SBP for RDN at 3 months was greater with baseline office heart rate ≥70 than <70 beats/min, suggesting an association between baseline heart rate and BP reduction after RDN. (SPYRAL PIVOTAL-SPYRAL HTN-OFF MED Study; NCT02439749).

Development and internal validation of a simple prognostic score for early sepsis risk stratification in the emergency department

OBJECTIVES

No validated, simple, powerful and continuously monitorable risk prediction tools are available for patients with sepsis during the early phases in the emergency department (ED). We sought to derive a novel Simple Sepsis Early Prognostic Score (SSEPS) composed of physiological indicators that do not depend on laboratory tests and that can be used by emergency clinicians in predicting outcomes in patients with sepsis.

DESIGN

Retrospective cohort analysis of a collected data source.

PARTICIPANTS

Patients with sepsis admitted to the ED of the West China Hospital of Sichuan University between July 2015 and June 2016 were included. We excluded patients who were pregnant, those with cardiac or respiratory arrest, and those using vasoactive drugs before admission to the ED.

PRIMARY OUTCOME MEASURES

28-day all-cause mortality.

RESULTS

The SSEPS consisted of age, heart rate, respiratory rate and altered consciousness. Patients in the development cohort with higher SSEPS had a significantly higher mortality (first tertile vs second tertile vs third tertile: 12.5% vs 28.6% vs 53.5%, p<0.001). The area under the receiver operating characteristic curve for SSEPS was 0.762 (95% CI 0.686 to 0.838), which was similar to Sequential Organ Failure Assessment (SOFA) (area under the curve: 0.745, 95% CI 0.692 to 0.798) and Acute Physiology and Chronic Health Evaluation (APACHE II) (area under the curve: 0.750, 95% CI 0.681 to 0.819). Moreover, the decision curve analysis showed that the net benefit of SSEPS was higher than SOFA and APACHE II at any probability threshold.

CONCLUSION

The SSEPS is simple and useful for clinicians in stratifying high-risk patients with sepsis at the early phase of ED admission.

Pathophysiology of sepsis-induced cardiomyopathy

Sepsis is the life-threatening organ dysfunction caused by a dysregulated host response to infection and is the leading cause of death in intensive care units. Cardiac dysfunction caused by sepsis, usually termed sepsis-induced cardiomyopathy, is common and has long been a subject of interest. In this Review, we explore the definition, epidemiology, diagnosis and pathophysiology of septic cardiomyopathy, with an emphasis on how best to interpret this condition in the clinical context. Advances in diagnostic techniques have increased the sensitivity of detection of myocardial abnormalities but have posed challenges in linking those abnormalities to therapeutic strategies and relevant clinical outcomes. Sophisticated methodologies have elucidated various pathophysiological mechanisms but the extent to which these are adaptive responses is yet to be definitively answered. Although the indications for monitoring and treating septic cardiomyopathy are clinical and directed towards restoring tissue perfusion, a better understanding of the course and implications of septic cardiomyopathy can help to optimize interventions and improve clinical outcomes.

The prognostic impact of the serum heart-type fatty acid-binding protein level in patients with sepsis who were admitted to the non-surgical intensive-care unit

Ongoing myocardial damage at the acme of the sepsis status has not been sufficiently evaluated. The clinical data of 160 sepsis patients who require intensive care and 127 outpatients with chronic heart failure (HF) were compared as a retrospective cohort study. Thereafter, the sepsis patients were divided into 3 groups according to the serum heart-type fatty acid-binding protein (H-FABP) quartiles [low H-FABP = Q1 (n = 39), middle H-FABP = Q2/Q3 (n = 81), and high H-FABP = Q4 group (n = 40)]. The H-FABP level was measured within 15 min of admission. The serum H-FABP levels in the sepsis patients [26.6 (9.3-79.0) ng/ml] were significantly higher than in the choric HF patients [6.6 (4.6-9.7) ng/ml]. A Kaplan-Meier curve showed that the survival rate of the high-H-FABP group was significantly lower than that of the middle- and low-H-FABP groups. The multivariate Cox regression analysis for the 365-day mortality showed that the high-H-FABP group (hazard ratio: 6.544, 95% confidence interval [CI] 2.026-21.140; p = 0.002) was an independent predictor of the 365-day mortality. The same trend in the prognostic impact was significantly (p = 0.015) observed in the cohort that had not been suffering from the cardiac disease before admission. The serum H-FABP level was an independent predictor of the 365-day mortality in the patients who were emergently hospitalized in the intensive-care unit due to sepsis. Ongoing myocardial damage was detected in the majority of patients with sepsis, suggesting that ongoing myocardial damage might be a candidate predictor of adverse outcomes in sepsis patients.

Afterload-related cardiac performance identifies cardiac impairment and associates with outcome in patients with septic shock: a retrospective cohort study

Background

Septic patients with cardiac impairment are with high mortality. Afterload-related cardiac performance (ACP), as a new tool for diagnosing septic cardiomyopathy (SCM), still needs to be evaluated for its impact on the prognosis for patients with septic shock.

Methods

In this retrospective study, 100 patients with septic shock undertaken PiCCO monitoring were included. The ability of ACP, cardiac index (CI), and cardiac power index (CPI) to discriminate between survivors and non-survivors was tested by comparing the area under the receiver operating characteristic curve (AUROC) analysis. Cox proportional hazards regression analyses were performed to assess the associations of ACP with day-28 mortality. Curve estimation was used to describe the relationship between the hazard ratio (HR) of death and ACP.

Results

ACP had a strong linear correlation with CI and CPI (P < 0.001). ACP demonstrated significantly greater discrimination for day-28 mortality than CI before adjusted [AUROC 0.723 (95% CI 0.625 to 0.822) vs. 0.580 (95% CI 0.468 to 0.692), P = 0.007] and CPI after adjusted [AUROC 0.693 (95% CI 0.590 to 0.797) vs. 0.448 (0.332 to 0.565), P < 0.001]. Compared with ACP > 68.78%, HR for ACP ≤ 68.78% was 3.55 (1.93 to 6.54) (P < 0.001). When adjusted with age, APACHE-II score, Vasoactive Inotropic Score, Lactate, CRRT, day-1 volume, fibrinogen and total bilirubin as possible confounders, and decrease ACP are still associated with increasing day-28 mortality (P < 0.05). An exponential relationship was observed between ACP12h and HR of day-28 death.

Conclusions

Our results suggested thatACP could improve mortality predictions when compared to CI and CPI. Decreased ACP was still an independent risk factor for increased day-28 mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40560-021-00549-5.

Sepsis-induced myocardial dysfunction: the role of mitochondrial dysfunction

INTRODUCTION

Sepsis-induced myocardial dysfunction (SIMD) is a condition manifested by an intrinsic myocardial systolic and diastolic dysfunction during sepsis, which is associated with worse clinical outcomes and a higher mortality.

MATERIALS AND METHODS

Several pathophysiological mechanisms including mitochondrial dysfunction, abnormal body immune reaction, metabolic reprogramming, excessive production of reactive oxygen species (ROS), and disorder of calcium regulation have been involved in SIMD. Mitophagy has potential role in protecting myocardial cells in sepsis, especially in survivors.

CONCLUSION

In the current review, we focus on the role of mitochondrial dysfunction and other mitochondria-related mechanisms including immunologic imbalance, energetic reprogramming, mitophagy, and pyroptosis in the mechanisms of SIMD.

Novel Insights into the Molecular Features and Regulatory Mechanisms of Mitochondrial Dynamic Disorder in the Pathogenesis of Cardiovascular Disease

Mitochondria maintain mitochondrial homeostasis through continuous fusion and fission, that is, mitochondrial dynamics, which is precisely mediated by mitochondrial fission and fusion proteins, including dynamin-related protein 1 (Drp1), mitofusin 1 and 2 (Mfn1/2), and optic atrophy 1 (OPA1). When the mitochondrial fission and fusion of cardiomyocytes are out of balance, they will cause their own morphology and function disorders, which damage the structure and function of the heart, are involved in the occurrence and progression of cardiovascular disease such as ischemia-reperfusion injury (IRI), septic cardiomyopathy, and diabetic cardiomyopathy. In this paper, we focus on the latest findings regarding the molecular features and regulatory mechanisms of mitochondrial dynamic disorder in cardiovascular pathologies. Finally, we will address how these findings can be applied to improve the treatment of cardiovascular disease.

Sepsis-Induced Cardiomyopathy: a Comprehensive Review

Purpose of Review

To briefly review epidemiology and pathophysiology of SICM and provide a more extensive review of the data on diagnostic and management strategies.

Recent Findings

SICM is likely underdiagnosed and that has mortality implications. Current evidence supports speckle tracking echocardiography to identify decreased contractility irrespective of left ventricular ejection fraction for the diagnosis of SICM. There continues to be a dearth of large clinical trials evaluating the treatment of SICM and current consensus focuses on supportive measures such as vasopressors and inotropes.

Summary

Sepsis is a significant cause of mortality, and sepsis-induced cardiomyopathy has both prognostic and management implications for these patients. Individualized work-up and management of these patients is crucial to improving outcomes.

Role of eotaxin-1/CCL11 in sepsis-induced myocardial injury in elderly patients

Myocardial injury is a serious complication of sepsis. The present study aimed to identify potential biomarkers of sepsis-induced myocardial injury. Differentially expressed genes (DEGs) in patients and mice with sepsis-induced myocardial injury were identified via bioinformatic analysis. The identified DEG was tested in elderly patients with sepsis-induced myocardial injury. We identified 19 co-expressed DEGs. The most significant DEG was eotaxin-1/CCL11. We enrolled 25 controls without infections and 28 patients with sepsis-induced myocardial injury. Six of patients died within 30 days. Circulating eotaxin-1/CCL11 levels were significantly higher in patients with sepsis-induced myocardial injury than controls and were higher in non-survivors than survivors (both P < 0.01). Eotaxin-1/CCL11 was positively correlated with troponin I (r=0.48, P=0.01), B-type natriuretic peptide (BNP, r=0.44, P=0.02), and white blood cell (WBC) count (r=0.41, P=0.03). For the prediction of 30-day mortality, eotaxin-1/CCL11 had the greatest discriminatory ability (AUC 0.97) compared with troponin I (AUC 0.89), BNP (AUC 0.80), and WBC count (AUC 0.86). Taken together, eotaxin-1/CCL11 was upregulated in sepsis-injured myocardium and circulating eotaxin-1/CCL11 was a biomarker for predicting severity and mortality of elderly patients with sepsis-induced myocardial injury. These results suggest that eotaxin-1/CCL11 may become a useful biomarkers and potential therapeutic target for sepsis-induced myocardial injury.

Valproic acid attenuates sepsis-induced myocardial dysfunction in rats by accelerating autophagy through the PTEN/AKT/mTOR pathway

AIMS

Sepsis is a leading cause of death and disability worldwide. Autophagy may play a protective role in sepsis-induced myocardial dysfunction (SIMD). The present study investigated whether valproic acid (VPA), a class I histone deacetylase (HDAC) inhibitor, can attenuate SIMD by accelerating autophagy.

MAIN METHODS

A sepsis model was established via the cecum ligation and puncture of male Sprague-Dawley rats. Cardiac injuries were measured using serum markers, echocardiographic cardiac parameters, and hematoxylin and eosin staining. Cardiac mitochondria injuries were detected with transmission electron microscopy, adenosine triphosphate (ATP) and cardiac mitochondrial DNA (mtDNA) contents. Cardiac oxidative levels were measured using redox markers in the cardiac homogenate. Real-time polymerase chain reaction (RT-PCR) and Western blot were performed to detect the expression levels of relative genes and proteins. HDAC binding to the phosphatase and tensin homolog deleted on chromosome ten (PTEN) promoters and histone acetylation levels of the PTEN promoters were analyzed via chromatin immunoprecipitation and quantitative RT-PCR.

KEY FINDINGS

VPA can ameliorate SIMD by enhancing the autophagy level of the myocardium to reduce mitochondrial damage, oxidative stress, and myocardial inflammation in septic rats. Moreover, this study demonstrated that VPA induces autophagy by inhibiting HDAC1- and HDAC3-mediated PTEN expression in the myocardial tissues of septic rats.

SIGNIFICANCE

This study found that VPA attenuates SIMD through myocardial autophagy acceleration by increasing PTEN expression and inhibiting the AKT/mTOR pathway. These findings preliminarily suggest that VPA may be a potential approach for the intervention and treatment of SIMD.

The role of mitochondria in sepsis-induced cardiomyopathy

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. Myocardial dysfunction, often termed sepsis-induced cardiomyopathy, is a frequent complication and is associated with worse outcomes. Numerous mechanisms contribute to sepsis-induced cardiomyopathy and a growing body of evidence suggests that bioenergetic and metabolic derangements play a central role in its development; however, there are significant discrepancies in the literature, perhaps reflecting variability in the experimental models employed or in the host response to sepsis. The condition is characterised by lack of significant cell death, normal tissue oxygen levels and, in survivors, reversibility of organ dysfunction. The functional changes observed in cardiac tissue may represent an adaptive response to prolonged stress that limits cell death, improving the potential for recovery. In this review, we describe our current understanding of the pathophysiology underlying myocardial dysfunction in sepsis, with a focus on disrupted mitochondrial processes.

The Septic Heart: Current Understanding of Molecular Mechanisms and Clinical Implications

Septic cardiomyopathy is a key feature of sepsis-associated cardiovascular failure. Despite the lack of consistent diagnostic criteria, patients typically exhibit ventricular dilatation, reduced ventricular contractility, and/or both right and left ventricular dysfunction with a reduced response to volume infusion. Although there is solid evidence that the presence of septic cardiomyopathy is a relevant contributor to organ dysfunction and an important factor in the already complicated therapeutic management of patients with sepsis, there are still several questions to be asked: Which factors/mechanisms cause a cardiac dysfunction associated with sepsis? How do we diagnose septic cardiomyopathy? How do we treat septic cardiomyopathy? How does septic cardiomyopathy influence the long-term outcome of the patient? Each of these questions is interrelated, and the answers require a profound understanding of the underlying pathophysiology that involves a complex mix of systemic factors and molecular, metabolic, and structural changes of the cardiomyocyte. The afterload-related cardiac performance, together with speckle-tracking echocardiography, could provide methods to improve the diagnostic accuracy and guide therapeutic strategies in patients with septic cardiomyopathy. Because there are no specific/causal therapeutics for the treatment of septic cardiomyopathy, the current guidelines for the treatment of septic shock represent the cornerstone of septic cardiomyopathy therapy. This review provides an up-to-date overview of the current understanding of the pathophysiology, summarizes the evidence of currently available diagnostic tools and treatment options, and highlights the importance of further urgently needed studies aimed at improving diagnosis and investigating novel therapeutic targets for septic cardiomyopathy.

[Heart in sepsis : Molecular mechanisms, diagnosis and therapy of septic cardiomyopathy]

An impairment of cardiac function is a key feature of cardiovascular failure associated with sepsis; however, its clinical relevance is still underestimated. Recent advancements in echocardiography in patients with septic shock enable a better characterization of septic cardiomyopathy by unmasking a severe, cardiac dysfunction even in the presence of preserved left ventricular ejection fraction. The pathophysiology of septic cardiomyopathy involves a complex mixture of systemic factors and molecular, metabolic, and structural changes of the cardiomyocytes. A better understanding of these factors will enable the discovery of new therapeutic targets for urgently needed disease-modifying therapeutic interventions. To date, the cornerstone of therapeutic management lies in control of the underlying infectious process and hemodynamic stabilization. This review summarizes the pathogenesis, diagnosis, and treatment of septic cardiomyopathy, and highlights the importance of further urgently needed studies aimed at improving diagnosis and treatment for septic cardiomyopathy.

Development of a Physiologically Based Pharmacokinetic Modelling Approach to Predict the Pharmacokinetics of Vancomycin in Critically Ill Septic Patients

BACKGROUND AND OBJECTIVES

Sepsis is characterised by an excessive release of inflammatory mediators substantially affecting body composition and physiology, which can be further affected by intensive care management. Consequently, drug pharmacokinetics can be substantially altered. This study aimed to extend a whole-body physiologically based pharmacokinetic (PBPK) model for healthy adults based on disease-related physiological changes of critically ill septic patients and to evaluate the accuracy of this PBPK model using vancomycin as a clinically relevant drug.

METHODS

The literature was searched for relevant information on physiological changes in critically ill patients with sepsis, severe sepsis and septic shock. Consolidated information was incorporated into a validated PBPK vancomycin model for healthy adults. In addition, the model was further individualised based on patient data from a study including ten septic patients treated with intravenous vancomycin. Models were evaluated comparing predicted concentrations with observed patient concentration-time data.

RESULTS

The literature-based PBPK model correctly predicted pharmacokinetic changes and observed plasma concentrations especially for the distribution phase as a result of a consideration of interstitial water accumulation. Incorporation of disease-related changes improved the model prediction from 55 to 88% within a threshold of 30% variability of predicted vs. observed concentrations. In particular, the consideration of individualised creatinine clearance data, which were highly variable in this patient population, had an influence on model performance.

CONCLUSION

PBPK modelling incorporating literature data and individual patient data is able to correctly predict vancomycin pharmacokinetics in septic patients. This study therefore provides essential key parameters for further development of PBPK models and dose optimisation strategies in critically ill patients with sepsis.

Circulating Histones Are Major Mediators of Cardiac Injury in Patients With Sepsis

OBJECTIVE

To investigate the impact of circulating histones on cardiac injury and dysfunction in a murine model and patients with sepsis.

DESIGN

Prospective, observational clinical study with in vivo and ex vivo translational laboratory investigations.

SETTING

General ICU and university research laboratory.

SUBJECTS

Sixty-five septic patients and 27 healthy volunteers. Twelve-week-old male C57BL/6N mice.

INTERVENTIONS

Serial blood samples from 65 patients with sepsis were analyzed, and left ventricular function was assessed by echocardiography. Patients' sera were incubated with cultured cardiomyocytes in the presence or absence of antihistone antibody, and cellular viability was assessed. Murine sepsis was initiated by intraperitoneal Escherichia coli injection (10(8) colony-forming unit/mouse) in 12-week-old male C57BL/6N mice, and the effect of antihistone antibody (10 mg/kg) was studied. Murine blood samples were collected serially, and left ventricular function was assessed by intraventricular catheters and electrocardiography.

MEASUREMENTS AND MAIN RESULTS

Circulating histones and cardiac troponins in human and murine plasma were quantified. In 65 patients with sepsis, circulating histones were significantly elevated compared with healthy controls (n = 27) and linearly correlated with cardiac troponin T levels (rs = 0.650; p < 0.001), noradrenaline doses required to achieve hemodynamic stability (rs = 0.608; p < 0.001), Sequential Organ Failure Assessment scores (p = 0.028), and mortality (p = 0.008). In a subset of 36 septic patients without prior cardiac disease, high histone levels were significantly associated with new-onset left ventricular dysfunction (p = 0.001) and arrhythmias (p = 0.01). Left ventricular dysfunction only predicted adverse outcomes when combined with elevated histones or cardiac troponin levels. Furthermore, patients' sera directly induced histone-specific cardiomyocyte death ex vivo, which was abrogated by antihistone antibodies. In vivo studies on septic mice confirmed the cause-effect relationship between circulating histones and the development of cardiac injury, arrhythmias, and left ventricular dysfunction.

CONCLUSION

Circulating histones are novel and important mediators of septic cardiomyopathy, which can potentially be utilized for prognostic and therapeutic purposes.

[Adequate fluid resuscitation in septic shock with high catecholamine doses]

BACKGROUND

Appropriate fluid resuscitation is a fundamental aspect for the hemodynamic management of septic shock patients and should ideally be achieved before vasopressors and positive inotropic substances are administered. The development of hemodynamic monitoring has revealed that in some cases patients had been improperly treated with high-dose catecholamines for initially insufficient fluid resuscitation. The aim of this study was to show that in some cases it is possible to actively reduce catecholamines by a volume challenge adapted according to the individual patient needs.

MATERIAL AND METHODS

In this retrospective observational study 29 patients with septic shock in a surgical intensive care unit (ICU) at a university hospital (17 male, 12 female, mean age 71 ± 10 years) on high-dose catecholamines (median values norepinephrine 0.204 µg/kg body weight/min, dobutamine 3.876 µg/kg/min and epinephrine 0.025 µg/kg/min, ranging up to 0.810 µg/kg/min, 22.222 µg/kg/min and 0.407 µg/kg/min in 28, 20 and 17 patients, respectively) were analyzed. The extremities of the patients were initially cold with a mottled marbled appearance whereas the mean arterial pressure (MAP) was ≥ 65 mmHg. The median central venous pressure (CVP) was 17 mmHg (range 55-34 mmHg) and the mean lactate concentration was 2.78 mmol/l (range 0.93-10.67 mmol/l). The standard therapy concept consisted of a forced volume challenge combined with active reduction of catecholamines to achieve an adequate fluid loading status, guided by the passive leg raising test (PLR), clinical signs and in 19 cases by hemodynamic monitoring (pulmonary artery catheter Vigilance II(™) n = 10, FloTrac(™), Vigileo(™) n = 9 and PreSep(™) n = 5; Edwards Life Sciences). The forced volume challenge was stopped after clinical improvement with rewarmed extremities, increasing diuresis volumes and lack of improvement by PLR.

RESULTS

Catecholamine doses could be significantly reduced in all patients: norepinephrine to 0 µg/kg/min, dobutamine to 1.852 µg/kg/min and epinephrine to 0 µg/kg/min (up to 0.133 µg/kg/min, 6.289 µg/kg/min and 0.091 µg/kg/min, respectively, p < 0.05 Wilcoxon signed rank test). Volume challenge test: + 4,500 ml Ringer solution (range 0-24,000 ml) and 1,000 ml hydroxyethyl starch (range 0-2,500 ml) and mean fluid balance + 6,465 ml (range + 2,040 ml to + 27,255 ml). The median weaning time from catecholamines was 12 h (range 4-43 h). After treatment all patients showed rewarmed extremities and a decrease in mean lactate levels from 2.78 mmol/l (range 0.93-10.67 mmol/l) to 2.05 mmol/l (range 0.7-5.4 mmol/l). The measured hemodynamic constellations showed clear interindividual differences but no cardiac deterioration occurred. The median oxygenation index (paO2/FiO2) showed a statistically insignificant change from 264 mmHg (range 75-418 mmHg) to 250 mmHg (range 120-467 mmHg). Of the patients 20 survived and 9 died.

CONCLUSION

It is possible to wean a substantial proportion of septic shock patients from high-dose catecholamines in combination with a needs-adapted forced volume challenge test. The importance of appropriate fluid loading prior to the use of high catecholamine doses should be a main subject of discussion in patients with severe septic shock and was confirmed in this study. This should be oriented to clinical and if possible, hemodynamic parameters and should not be underestimated.

Impaired heart rate regulation and depression of cardiac chronotropic and dromotropic function in polymicrobial sepsis

The scope of cardiac pathophysiology in sepsis has not been fully defined. Accordingly, we evaluated the effects of sepsis on heart rate (HR), HR variability, and conduction parameters in a murine model of sepsis. Electrocardiograms were recorded noninvasively from conscious mice before and after cecal ligation and puncture (CLP) or sham surgery. Responses of isolated atria to tyramine and isoproterenol were quantified to assess the functional state of sympathetic nerves and postjunctional sensitivity to adrenergic stimulation. Cecal ligation and puncture mice had lower HR compared with sham at 16 to 18 h postsurgery (sham, 741 ± 7 beats/min; CLP, 557 ± 31 beats/min; n = 6/group; P < 0.001), and there was significant prolongation of the PR, QRS, and QTc intervals. Slowing of HR and conduction developed within 4 to 6 h after CLP and were preceded by a decrease in HR variability. Treatment of CLP mice with isoproterenol (5 mg/kg, intraperitoneally) at 25 h after surgery failed to increase HR or decrease conduction intervals. The lack of in vivo response to isoproterenol cannot be attributed to hypothermia because robust chronotropic and inotropic responses to isoproterenol were evoked from isolated atria at 25 °C and 30 °C. These findings demonstrate that impaired regulation of HR (i.e., reduced HR variability) develops before the onset of overt cardiac rate and conduction changes in septic mice. Subsequent time-dependent decreases in HR and cardiac conduction can be attributed to hypothermia and would contribute to decreased cardiac output and organ perfusion. Because isolated atria from septic mice showed normal responsiveness to adrenergic stimulation, we conclude that impaired effectiveness of isoproterenol in vivo can be attributed to reversible effects of systemic factors on adrenergic receptors and/or postreceptor signaling.

Resting heart rate: risk indicator and emerging risk factor in cardiovascular disease

Resting heart rate is central to cardiac output and is influenced by changes occurring in numerous diseases. It predicts longevity and cardiovascular diseases, and current evidence suggests that it is also an important marker of outcome in cardiovascular disease, including heart failure. Beta-blockers improve outcomes in heart failure; however, they have effects outside reducing heart rate. Ivabradine has demonstrated efficacy in reducing rehospitalizations and mortality in heart failure and in improving exercise tolerance and reducing angina attacks in patients with coronary artery disease, whereas selective heart rate reduction may also prove to be beneficial in therapeutic areas outside those in which ivabradine has already demonstrated clinical efficacy. This review provides an update on the associations between heart rate and cardiovascular outcomes in various conditions, the experimental effects of heart rate reduction with ivabradine, and the potential new indications in cardiovascular disease.

[Indocyanine green elimination for the evaluation of liver function: prognostic value in patients with community-acquired sepsis]

BACKGROUND

The aim of our clinical study was to correlate liver function measured by indocyanine green (ICG) elimination and clinical outcomes in patients with an early stage of community-acquired sepsis (CAS).

MATERIALS AND METHODS

A total of 341 patients (≥ 18 years) presenting with suspicion of CAS or evidence of an infection and fulfillment of ≥ 2 systemic inflammatory response syndrome (SIRS) criteria were included in the observational study"Prognosis of early sepsis 2" (Prognose der frühen Sepsis 2, ProFS 2). Patients who had been hospitalized within the last 7 days were excluded. In a subgroup of these patients (n = 72) who were transferred to an intensive or intermediate care unit according to the clinical judgment of the treating physicians, ICG elimination (plasma disappearance rate, ICG-PDR; 15 min retention rate, ICG-R15) was assessed by using a noninvasive monitoring system (LiMON, PULSION Medical Systems, Germany). ICG-PDR and -R15 were determined on the day of admission (n = 72) and after 96 h (n = 34). The primary end point of the study was defined as death within 30 days. Secondary endpoints were need for renal replacement therapy, requirement for invasive mechanical ventilation, and length of stay in an intermediate or intensive care unit.

RESULTS AND CONCLUSION

In contrast to patients with sepsis or severe sepsis, ICG elimination was found to be significantly impaired in patients with septic shock. Furthermore, a significant predictive value of ICG-PDR and -R15 on the day of admission for the need for subsequent renal replacement therapy (n = 12) was observed. In addition, reduced ICG elimination was associated with a longer stay in an intermediate or intensive care unit. However, ICG elimination on admission could not predict 30-day mortality (n = 14) or requirement of mechanical ventilation (n = 20).