Prognostic Value of Secretoneurin in Patients With Severe Sepsis and Septic Shock: Data From the Albumin Italian Outcome Sepsis Study

Young hearts, early risks: novel cardiovascular biomarkers in former very preterm infants at kindergarten age

BACKGROUND

Preterm birth is associated with long-term cardiovascular morbidity and mortality. In adults, fibroblast growth factor-23 (FGF-23), α-Klotho, and secretoneurin have all garnered attention as cardiovascular biomarkers, but their utility in pediatric populations has not yet been ascertained. The aim of this pilot study was to evaluate these novel cardiovascular biomarkers and their association with indicators of cardiovascular impairment in the highly vulnerable population of former very preterm infants.

METHODS

Five- to seven-year-old children born at < 32 weeks' gestation were eligible for the study. Healthy same-aged children born at term served as controls. Biomarkers were quantified in fasting blood samples, and echocardiographic measurements including assessment of aortic elastic properties were obtained.

RESULTS

We included 26 former very preterm infants and 21 term-born children in the study. At kindergarten age, former very preterm infants exhibited significantly higher plasma concentrations of biologically active intact FGF-23 (iFGF-23; mean 43.2 pg/mL vs. 29.1 pg/mL, p = 0.003) and secretoneurin (median 93.8 pmol/L vs. 70.5 pmol/L, p = 0.046). iFGF-23 inversely correlated with distensibility of the descending aorta.

CONCLUSION

In preterm-born children, iFGF-23 and secretoneurin both offer prospects as valuable cardiovascular biomarkers, potentially allowing for risk stratification and timely implementation of preventive measures.

IMPACT

Former very preterm infants have increased plasma concentrations of the novel cardiovascular biomarkers intact fibroblast growth factor-23 (iFGF-23) and secretoneurin at kindergarten age. Increases in iFGF-23 concentrations are associated with decreased distensibility of the descending aorta even at this early age. Monitoring of cardiovascular risk factors is essential in individuals with a history of preterm birth. Both iFGF-23 and secretoneurin hold promise as clinically valuable biomarkers for risk stratification, enabling the implementation of early preventive measures.

Predictors and nomogram of in-hospital mortality in sepsis-induced myocardial injury: a retrospective cohort study

BACKGROUND

Sepsis-induced myocardial injury (SIMI) is a common organ dysfunction and is associated with higher mortality in patients with sepsis. We aim to construct a nomogram prediction model to assess the 28-day mortality in patients with SIMI. .

METHOD

We retrospectively extracted data from Medical Information Mart for Intensive Care (MIMIC-IV) open-source clinical database. SIMI was defined by Troponin T (higher than the 99th percentile of upper reference limit value) and patients with cardiovascular disease were excluded. A prediction model was constructed in the training cohort by backward stepwise Cox proportional hazards regression model. The concordance index (C-index), area under the receiver operating characteristics curve (AUC), net reclassification improvement (NRI), integrated discrimination improvement (IDI), calibration plotting and decision-curve analysis (DCA) were used to evaluate the nomogram.

RESULTS

1312 patients with sepsis were included in this study and 1037 (79%) of them presented with SIMI. The multivariate Cox regression analysis in all septic patients revealed that SIMI was independently associated with 28-day mortality of septic patients. The risk factors of diabetes, Apache II score, mechanical ventilation, vasoactive support, Troponin T and creatinine were included in the model and a nomogram was constructed based on the model. The C-index, AUC, NRI, IDI, calibration plotting and DCA showed that the performance of the nomogram was better than the single SOFA score and Troponin T.

CONCLUSION

SIMI is related to the 28-day mortality of septic patients. The nomogram is a well-performed tool to predict accurately the 28-day mortality in patients with SIMI.

Prognostic value of secretoneurin in chronic heart failure. Data from the GISSI-Heart Failure trial

BACKGROUND

Circulating secretoneurin (SN) concentrations have been found to provide prognostic information in patients with acute heart failure. We wanted to assess whether SN would improve prognostication also in patients with chronic heart failure (HF) in a large multicenter trial.

METHODS

We measured plasma SN concentrations at randomization (n=1224) and after 3 months (n=1103) in patients with chronic, stable HF from the GISSI-HF study. The co-primary endpoints were (1) time to death or (2) admission to hospital for cardiovascular reasons.

RESULTS

Mean age was 67 years and 80% were male. Median (quartile 1-3) SN concentrations were 42.6 (35.0-62.8) pmol/L on randomization and 42.0 (34.5-53.1) pmol/L after 3 months, which are higher than SN concentrations in healthy subjects. Higher SN concentrations at randomization were associated with lower body-mass index (BMI), lower systolic blood pressure, lower estimated glomerular filtration rate (eGFR), higher B-type natriuretic peptide (BNP) concentrations, and diagnosis of chronic obstructive pulmonary disease. During median follow-up of 3.9 years, 344 patients (27.0%) died. After adjusting for age, sex, left ventricular ejection fraction, BMI, functional class, ischemic etiology, heart rate, blood pressure, eGFR, bilirubin, comorbidities, and BNP concentrations, logarithmically transformed SN concentrations on randomization were associated with mortality (HR 2.60 (95% CI 1.01-6.70), p=0.047). SN concentrations were also associated with admission to hospital for cardiovascular reasons, but the association was attenuated and no longer significant in multivariable analysis.

CONCLUSION

Plasma SN concentrations provided incremental prognostic information to established risk indices and biomarkers in a large cohort of chronic HF patients.

Septic cardiomyopathy: A narrative review

Sepsis is a systemic inflammatory response syndrome of suspected or documented infectious origin, whose outcome is multiorgan failure. Sepsis-induced myocardial dysfunction (SIMD), present in more than 50% of septic patients, is characterized by (i) left ventricular (LV) dilatation with normal or low filling pressure, (ii) right and/or LV (systolic and/or diastolic) dysfunction and (iii) reversibility. Since the first definition proposed by Parker et al. in 1984, attempts have been made to define SIMD. Many parameters are used to assess cardiac function in septic patients, sometimes making it more difficult to measure due to the intrinsic hemodynamical changes in this condition. Nevertheless, with advanced echocardiographic techniques, such as speckle tracking analysis, it is possible to diagnose and assess systolic and diastolic dysfunction, even in the earliest stages of sepsis. Cardiac magnetic resonance imaging brings new insights into the reversibility of this condition. Many uncertainties still remain regarding the mechanisms, characteristics, treatment and even prognosis of this condition. There are also inconsistent conclusions from studies, therefore this review attempts to summarize our current knowledge of SIMD.

The Overexpression of miR-377 Aggravates Sepsis-Induced Myocardial Hypertrophy by Binding to Rcan2 and Mediating CaN Activity

Sepsis remains a complicated and incompletely understood syndrome, and myocardial dysfunction is one of the main complications contributing to poor clinical outcomes. Accumulating evidence has revealed the critical involvement of the deregulated expression of specific microRNAs (miRNAs) in cardiac pathologies caused by sepsis. Intriguingly, miR-377 has been correlated with cardiomyocyte apoptosis, whereas its effect on myocardial hypertrophy remains to be illustrated. Thus, the current study sets out to explore the impact and underlying mechanism of miR-377 on myocardial hypertrophy induced by sepsis. The expression pattern of miR-377 was detected in myocardial tissues of septic mice induced by cecal ligation-perforation (CLP). We found that miR-377 was highly expressed in myocardial tissues of CLP-induced septic mice with cardiomyocyte hypertrophy. Besides, miR-377 inhibition could relieve cardiomyocyte hypertrophy and reduce inflammation in septic mice. Further, mechanistic studies found that miR-377 could target Rcan2 and then regulate calcineurin (CaN) activity via Ca2+/CaN signaling pathway. Collectively, our findings illuminate that miR-377 enhances myocardial hypertrophy caused by sepsis, by targeting Rcan2 and further regulating the Ca2+/CaN signaling pathway. This work highlights downregulation of miR-377 as a novel target for the management of sepsis-induced myocardial hypertrophy.

Effects of Albumin Supplements on In-Hospital Mortality in Patients with Sepsis or Septic Shock: A Systemic Review and Meta-Analysis

Objective

To explore the clinical effects of albumin supplements on the basis of crystalloid solution in patients with sepsis or septic shock.

Methods

The online databases including PubMed, Web of Science, Cochrane Library, and EMBASE were comprehensively searched from inception to June 28, 2021, with the keywords including “albumin,” “sepsis,” or “septic shock.” Retrospective cohort (RC) and randomized controlled trials (RCT) were included for analysis. Two authors independently searched and analyzed the literature. The in-hospital mortality at 7 days and 28 days, duration of mechanical ventilation, renal replacement therapy, length of ICU stay, and length of hospital stay were compared between patients with albumin supplements and crystalloid solution and those with crystalloid alone.

Results

A total of 10 studies with 6463 patients were eventually included for meta-analysis. The in-hospital mortality of patients at 7 days (OR = 1.00, 95% CI: 0.81–1.23) and 28 days (OR = 1.02, 95% CI: 0.91–1.13) did not show a significant difference between the two groups of patients. Also, the pooled results demonstrated no significant differences in duration of mechanical ventilation (OR = 0.29, 95% CI: −0.05–0.63), renal replacement therapy (WMD = 1.15, 95% CI: 0.98–1.35), length of ICU stay (WMD = −0.07, 95% CI: −0.62–0.48), and length of hospital stay (WMD = −0.09, 95% CI: −0.70–0.52) between patients receiving albumin plus crystalloid solution and those with crystalloid solution alone.

Conclusion

Albumin supplements on the basis of crystalloid solution did not improve the 7-day and 28-dayin-hospital mortality in patients with sepsis or septic shock compared with those with crystalloid solution alone.

Association between Vitamin C Deficiency and Mortality in Patients with Septic Shock

The prognostic value of low vitamin C levels has not been well investigated in patients with septic shock. We aimed to evaluate the association of vitamin C deficiency with mortality in patients with septic shock. We conducted a retrospective analysis of 165 patients with septic shock from a prospective multicenter trial and institutional sepsis registry between April 2018 and January 2020. The primary outcome was 28-day mortality. The patients were categorized into vitamin C deficiency and normal groups based on a vitamin C cutoff level of 11.4 mmol/L. Multivariable Cox regression analysis was performed to examine the association between vitamin C levels and 28-day mortality. A total of 165 patients was included for analysis and 77 (46.7%) had vitamin C deficiency. There was no significant difference in the 28-day mortality rate between the vitamin C deficiency group and the normal group (23.4% (n = 18/77) vs. 13.6% (n = 12/88), p = 0.083). Multivariable Cox proportional hazard analysis showed vitamin C deficiency to be associated with increased risk of 28-day mortality (adjusted hazard ratio, 2.65, 95% confidence interval (CI), 1.08–6.45; p = 0.032). Initial vitamin C deficiency was associated with a higher risk of 28-day mortality in patients with septic shock after adjusting for intravenous administration of vitamin C and thiamine, baseline characteristics, laboratory findings, and severity of illness.

Identification of Prognostic Factors in Patients With Streptococcus Bloodstream Infection

Aim

The purpose of this study was to explore prognostic factors of bloodstream infections (BSIs), a common severe infection and a major cause of mortality worldwide, so as to construct a prognosis model of patients with BSI.

Materials and Methods

Clinical and biochemical test data were obtained retrospectively from the medical records of 562 patients with BSI who had been treated at a single center; the end point was 60 days of all-cause death. The chi-square test was used to compare the mortality of patients grouped by the types of antibiotic treatment. The logistic regression analysis was adopted to identify prognostic factors; the Kaplan–Meier survival curve and log-rank test were conducted to compare the survival rate of patients with different prognostic factors; the receiver operating characteristic (ROC) curve was used to estimate the predictive value of different prognostic factors.

Results

Of the 562 patients, 455 survived (80.96%), and 107 died (19.04%). The mortality rate of patients treated with a combination of antibiotics (25.40%) was higher than that treated with a single antibiotic (15.82%). Univariate analysis identified 19 prognostic factors for patients with BSI, including gender, age, diabetes, malignant tumor (non-blood system), total hospitalization time, alanine aminotransferase, aspartate aminotransferase, total protein, albumin, total bilirubin, direct bilirubin, creatinine, ratio of granulocytes, fibrinogen, D-dimer, platelet, C-reactive protein, shock, and respiratory failure (P < 0.05). Multivariate analysis indicated that albumin (odds ratio [OR] = 0.94, 95% confidence interval [CI]: 0.89–0.99), fibrinogen (OR = 0.61, 95%CI: 0.46–0.82), shock (OR = 16.61, 95%CI: 7.00–39.41), and respiratory failure (OR = 47.53, 95%CI: 19.93–133.64) were independent factors. The combination of four indicators demonstrated a favorable predictive value for the 60-day outcome of patients with BSI, with an area under the ROC of 0.96 (95%CI: 0.94–0.99), sensitivity of 90.65%, specificity of 94.95%, and accuracy of 94.13%.

Conclusions

Shock, respiratory failure, albumin, and fibrinogen are potential independent prognostic factors for 60-day mortality.

Rutin Inhibits Cardiac Apoptosis and Prevents Sepsis-Induced Cardiomyopathy

Rutin is a flavanol-type polyphenol that consists of flavanol quercetin and the disaccharide rutinose, which has been reported to exert various biological effects such as antioxidant and anti-inflammatory activities. It is not clear whether rutin has a protective effect on sepsis-induced cardiomyopathy (SIC). In this study, we used male C57BL/6 mice and cecal ligation and puncture (CLP) surgery to establish the model of SIC. Rutin was precautionarily treated (50, 100, 200 mg/kg per day, 7 days) before CLP. The results showed that rutin pretreatment (100, 200 mg/kg per day, 7 days) reduced the mortality of murine sepsis. We chose the 100 mg/kg dose for further studies. Mice were pretreatment with rutin (100 mg/kg per day, 7 days) before subjected to CLP, and myocardial tissue and blood samples were collected 24 h after CLP. Serum levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and cTNT decreased, while interleukin-10 (IL-10) increased with rutin pretreatment. The cardiomyocytes apoptosis and mitochondrial dysfunction were also alleviated with rutin pretreatment. In conclusion, this study confirmed the efficacy of rutin-enriched diet in the prophylaxis of cardiac apoptosis and cardiac injury induced by CLP in mouse model. It provides a potential new approach on SIC prophylaxis in sepsis.

Biological variation of secretoneurin; a novel cardiovascular biomarker implicated in arrhythmogenesis

BACKGROUND

Secretoneurin is a novel prognostic biomarker that may predict mortality in heart failure and the occurrence of ventricular arrhythmias. This study reports the within subject variation (CVI), between subject variation (CVG), reference change values (RCV) and index of individuality (II) of secretoneurin.

METHODS

Thirty healthy volunteers were included. Non-fasting samples were obtained between 8 and 10 am once a week for ten weeks. Secretoneurin was analyzed in duplicate using ELISA. No outliers were present according to Burnett and Reeds' criteria. Simple linear regression did not identify significant trends. Variance homogeneity in the analytical variance and CVI were tested using Cochrane's and Bartlett's tests and four participants were excluded. Calculation of CVI, CVG and RCV were done on ln transformed data as described by Fokkema, the II was calculated using retransformed data.

RESULTS

The median age of the participants was 36 years and 53% were female. Non-fasting glucose, eGFR(CKD-EPI), cTnT and NT-proBNP concentrations were within the normal range. Median secretoneurin concentrations were 38 pmol/L (women) and 33 pmol/L (men), p-value < 0.001. CVI and CVG were 9.8% (CI 8.7% to 11.0%) and 20.0 (CI 15.4% to 28.0%), respectively. RCV were 38.7% (CI 35.5% to 42.7%) and -27.9 (CI -29.9 to -26.2) and the II were 0.60 (CI 0.42-0.78). No gender differences were present.

CONCLUSION

Secretoneurin has a fairly low CVI, CVG, RCV and II, indicating that it could be suitable as a diagnostic or prognostic biomarker and that delta values in serial samplings may be preferable for identifying clinical changes.

Higher levels of IgA and IgG at sepsis onset are associated with higher mortality: results from the Albumin Italian Outcome Sepsis (ALBIOS) trial

Background

The role of intravenous immunoglobulins (IVIG) during sepsis is controversial, as different trials on IVIG have observed inconsistent survival benefits. We aimed to elucidate the possible association and clinical significance between circulating levels of immunoglobulins.

Methods

In a subset of 956 patients with severe sepsis and septic shock of the multicentre, open-label RCT ALBIOS, venous blood samples were serially collected 1, 2, and 7 days after enrolment (or at ICU discharge, whichever came first). IgA, IgG and IgM concentrations were assayed in all patients on day 1 and in a subgroup of 150 patients on days 2 and 7. Ig concentrations were measured employing a turbidimetric assay, OSR61171 system.

Results

IgA on day 1 had a significant predictive value for both 28-day and 90-day mortality (28-day mortality, HR: 1.50 (95% CI 1.18–1.92); 90-day mortality, HR: 1.54 (95% CI 1.25–1.91)). IgG, but not IgM, on day 1 showed similar results for 28-day (HR 1.83 (95% CI 1.33–2.51) and 90-day mortality HR: 1.66 (95% CI 1.23–2.25)). In addition, lower levels of IgG but not of IgA and IgM, at day 1 were associated with significantly higher risk of secondary infections (533 [406–772] vs 600 [452–842] mg/dL, median [Q1–Q3], p = 0.007).

Conclusions

In the largest cohort study of patients with severe sepsis or septic shock, we found that high levels of IgA and IgG on the first day of diagnosis were associated with a decreased 90-day survival. No association was found between IgM levels and survival. As such, the assessment of endogenous immunoglobulins could be a useful tool to identify septic patients at high risk of mortality.

Trial registration #NCT00707122, Clinicaltrial.gov, registered 30 June 2008

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00952-z.

The Correlation Between Whole Blood Copper (Cu), Zinc (Zn) Levels and Cu/Zn Ratio and Sepsis-Induced Left Ventricular Systolic Dysfunction (SILVSD) in Patients with Septic Shock: A Single-Center Prospective Observational Study

Purpose

This study aimed to explore relationships between whole blood copper (Cu), zinc (Zn) and Cu/Zn ratio and cardiac dysfunction in patients with septic shock.

Subjects and Methods

Between April 2018 and March 2020, septic shock patients with sepsis-induced left ventricular systolic dysfunction (SILVSD, left ventricular ejection fraction, LVEF<50%) and with no sepsis-induced myocardial dysfunction (non-SIMD, septic shock alone and LVEF>50%) and controls were prospectively enrolled. Whole blood Cu and Zn levels were measured using flame atomic absorption spectrophotometry.

Results

Eighty-six patients with septic shock including both 41 SILVSD and 45 non-SIMD and 25 controls were studied. Whole blood Cu levels and Cu/Zn ratio were significantly higher and Zn levels were lower in SILVSD compared with non-SIMD and controls (Cu, p=0.009, <0.001; Zn, p=0.029, <0.001; Cu/Zn ratio, p=0.003, <0.001). Both increased whole blood Cu and Cu/Zn ratio and reduced Zn were associated with lower LVEF (all p<0.001) and higher amino-terminal pro-B-type natriuretic peptide (NT-proBNP) (Cu, p=0.002; Zn, p<0.001; Cu/Zn ratio, p<0.001) and had predictive values for SILVSD (Cu, AUC=0.666, p=0.005; Zn, AUC=0.625, p=0.039; Cu/Zn ratio, AUC=0.674, p=0.029). Whole blood Cu levels and Cu/Zn ratio were increased but Zn levels were reduced in non-survivors compared with survivors (Cu, p<0.001; Zn, p<0.001; Cu/Zn ratio, p<0.001). Whole blood Cu and Zn displayed the value of predicting 28-day mortality (Cu, AUC = 0.802, p<0.001; Zn, AUC=0.869, p<0.001; Cu/Zn ratio, AUC=0.902, p<0.001).

Conclusion

Findings of the study suggest that whole blood Cu levels and Cu/Zn ratio are increased in SILVSD patients and positively correlated with cardiac dysfunction, while whole blood Zn levels are reduced and negatively associated with cardiac dysfunction. Moreover, both whole blood Cu, Zn and Cu/Zn ratio might distinguish between SILVSD and non-SIMD in septic shock patients and predict 28-day mortality.

Trial Registration

Registered at http://www.chictr.org.cn/ChiCTR1800015709.

Performance of a Novel Research-Use-Only Secretoneurin ELISA in Patients with Suspected Acute Coronary Syndrome: Comparison with an Established Secretoneurin Radioimmunoassay

BACKGROUND

Circulating secretoneurin (SN) concentrations, as measured by established radioimmunoassay (RIA), risk stratify patients with cardiovascular disease. We now report data for a recently developed research-use-only SN enzyme-linked immunosorbent assay (ELISA) in patients with suspected acute coronary syndrome (ACS).

METHODS

SN ELISA was developed according to industry standards and tested in 401 unselected chest pain patients. Blood samples were drawn <24 h from admission, and we adjudicated all hospitalizations as ACS or non-ACS. The mean follow-up was 6.2 years.

RESULTS

SN ELISA with 2 monoclonal sheep anti-SN antibodies has a measuring range of 10-250 pmol/L and demonstrates excellent analytical precision and accuracy across the range of SN concentrations. SN measured by ELISA and RIA correlated in the chest pain patients: rho = 0.39, p < 0.001. SN concentrations were higher in ACS patients (n = 161 [40%]) than in non-ACS patients (n = 240) for both assays, with an area under the curve (AUC) of 0.66 (95% CI: 0.61-0.71) for ELISA and 0.59 (0.54-0.65) for RIA. SN concentrations were also higher in nonsurvivors (n = 65 [16%]) than survivors, with an AUC of 0.72 (0.65-0.79) for ELISA versus 0.64 (0.56-0.72) for RIA, p = 0.007, for difference between assays. Adjusting for age, sex, blood pressure, previous myocardial infarction, atrial fibrillation, and heart failure in multivariable analysis, SN concentrations as measured by ELISA, but not RIA, remained associated with mortality, with a hazard ratio of 1.71 (1.03-2.84), p = 0.038.

CONCLUSIONS

The novel SN ELISA has excellent performance, higher AUC for diagnosis, and superior prognostic accuracy compared to the established RIA in chest pain patients.

Albumin replacement therapy in immunocompromised patients with sepsis - Secondary analysis of the ALBIOS trial

BACKGROUND

The best fluid replacement strategy and the role of albumin in immunocompromised patients with sepsis is unclear.

METHODS

We performed a secondary analysis of immunocompromised patients enrolled in the ALBIOS trial which randomized patients with severe sepsis or septic shock to receive either 20% albumin (target 30 g per liter or more) and crystalloid or crystalloid alone during ICU stay.

RESULTS

Of 1818 patients originally enrolled, 304 (16.4%) were immunocompromised. One-hundred-thirty-nine (45.7%) patients were randomized in the albumin while 165 (54.2%) in the crystalloid group. At 90 days, 69 (49.6%) in the albumin group and 89 (53.9%) in the crystalloids group died (hazard ratio - HR - 0.94; 95% CI 0.69-1.29). No differences were observed with regards to 28-day mortality, SOFA score (and sub-scores), length of stay in the ICU and in the hospital, proportion of patients who had developed acute kidney injury or received renal replacement therapy, duration of mechanical ventilation. Albumin was not independently associated with a higher or lower 90-day mortality (HR 0.979, 95% CI 0.709-1.352) as compared to crystalloid.

CONCLUSION

Albumin replacement during the ICU stay, as compared with crystalloids alone, did not affect clinical outcomes in a cohort of immunocompromised patients with sepsis.

Circulating Secretoneurin Concentrations After Cardiac Surgery: Data From the FINNish Acute Kidney Injury Heart Study

OBJECTIVES

Secretoneurin is associated with cardiomyocyte Ca handling and improves risk prediction in patients with acute myocardial dysfunction. Whether secretoneurin improves risk assessment on top of established cardiac biomarkers and European System for Cardiac Operative Risk Evaluation II in patients undergoing cardiac surgery is not known.

DESIGN

Prospective, observational, single-center sub-study of a multicenter study.

SETTING

Prospective observational study of survival in patients undergoing cardiac surgery.

PATIENTS

A total of 619 patients undergoing cardiac surgery.

INTERVENTIONS

Patients underwent either isolated coronary artery bypass graft surgery, single noncoronary artery bypass graft surgery, two procedures, or three or more procedures. Procedures other than coronary artery bypass graft were valve surgery, surgery on thoracic aorta, and other cardiac surgery.

MEASUREMENTS AND MAIN RESULTS

We measured preoperative and postoperative secretoneurin concentrations and adjusted for European System for Cardiac Operative Risk Evaluation II, N-terminal pro-B-type natriuretic peptide, and cardiac troponin T concentrations in multivariate analyses. During 961 days of follow-up, 59 patients died (9.5%). Secretoneurin concentrations were higher among nonsurvivors compared with survivors, both before (168 pmol/L [quartile 1-3, 147-206 pmol/L] vs 160 pmol/L [131-193 pmol/L]; p = 0.039) and after cardiac surgery (173 pmol/L [129-217 pmol/L] vs 143 pmol/L [111-173 pmol/L]; p < 0.001). Secretoneurin concentrations decreased from preoperative to postoperative measurements in survivors, whereas we observed no significant decrease in secretoneurin concentrations among nonsurvivors. Secretoneurin concentrations were weakly correlated with established risk indices. Patients with the highest postoperative secretoneurin concentrations had worse outcome compared with patients with lower secretoneurin concentrations (p < 0.001 by the log-rank test) and postoperative secretoneurin concentrations were associated with time to death in multivariate Cox regression analysis: hazard ratio lnsecretoneurin 2.96 (95% CI, 1.46-5.99; p = 0.003). Adding postoperative secretoneurin concentrations to European System for Cardiac Operative Risk Evaluation II improved patient risk stratification, as assessed by the integrated discrimination index: 0.023 (95% CI, 0.0043-0.041; p = 0.016).

CONCLUSIONS

Circulating postoperative secretoneurin concentrations provide incremental prognostic information to established risk indices in patients undergoing cardiac surgery.

Secretoneurin Is an Endogenous Calcium/Calmodulin-Dependent Protein Kinase II Inhibitor That Attenuates Ca2+-Dependent Arrhythmia

BACKGROUND

Circulating SN (secretoneurin) concentrations are increased in patients with myocardial dysfunction and predict poor outcome. Because SN inhibits CaMKIIδ (Ca²⁺/calmodulin-dependent protein kinase IIδ) activity, we hypothesized that upregulation of SN in patients protects against cardiomyocyte mechanisms of arrhythmia.

METHODS

Circulating levels of SN and other biomarkers were assessed in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT; n=8) and in resuscitated patients after ventricular arrhythmia-induced cardiac arrest (n=155). In vivo effects of SN were investigated in CPVT mice (RyR2 [ryanodine receptor 2]-R2474S) using adeno-associated virus-9-induced overexpression. Interactions between SN and CaMKIIδ were mapped using pull-down experiments, mutagenesis, ELISA, and structural homology modeling. Ex vivo actions were tested in Langendorff hearts and effects on Ca²⁺ homeostasis examined by fluorescence (fluo-4) and patch-clamp recordings in isolated cardiomyocytes.

RESULTS

SN levels were elevated in patients with CPVT and following ventricular arrhythmia-induced cardiac arrest. In contrast to NT-proBNP (N-terminal pro-B-type natriuretic peptide) and hs-TnT (high-sensitivity troponin T), circulating SN levels declined after resuscitation, as the risk of a new arrhythmia waned. Myocardial pro-SN expression was also increased in CPVT mice, and further adeno-associated virus-9-induced overexpression of SN attenuated arrhythmic induction during stress testing with isoproterenol. Mechanistic studies mapped SN binding to the substrate binding site in the catalytic region of CaMKIIδ. Accordingly, SN attenuated isoproterenol induced autophosphorylation of Thr287-CaMKIIδ in Langendorff hearts and inhibited CaMKIIδ-dependent RyR phosphorylation. In line with CaMKIIδ and RyR inhibition, SN treatment decreased Ca²⁺ spark frequency and dimensions in cardiomyocytes during isoproterenol challenge, and reduced the incidence of Ca²⁺ waves, delayed afterdepolarizations, and spontaneous action potentials. SN treatment also lowered the incidence of early afterdepolarizations during isoproterenol; an effect paralleled by reduced magnitude of L-type Ca²⁺ current.

CONCLUSIONS

SN production is upregulated in conditions with cardiomyocyte Ca²⁺ dysregulation and offers compensatory protection against cardiomyocyte mechanisms of arrhythmia, which may underlie its putative use as a biomarker in at-risk patients.

Age-Dependent Myocardial Dysfunction in Critically Ill Patients: Role of Mitochondrial Dysfunction

Myocardial dysfunction is common in septic shock and post-cardiac arrest but manifests differently in pediatric and adult patients. By conventional echocardiographic parameters, biventricular systolic dysfunction is more prevalent in children with septic shock, though strain imaging reveals that myocardial injury may be more common in adults than previously thought. In contrast, diastolic dysfunction in general and post-arrest myocardial systolic dysfunction appear to be more widespread in the adult population. A growing body of evidence suggests that mitochondrial dysfunction mediates myocardial depression in critical illness; alterations in mitochondrial electron transport system function, bioenergetic production, oxidative and nitrosative stress, uncoupling, mitochondrial permeability transition, fusion, fission, biogenesis, and autophagy all may play key pathophysiologic roles. In this review we summarize the epidemiologic and clinical phenotypes of myocardial dysfunction in septic shock and post-cardiac arrest and the multifaceted manifestations of mitochondrial injury in these disease processes. Since neonatal and pediatric-specific data for mitochondrial dysfunction remain sparse, conclusive age-dependent differences are not clear; instead, we highlight what evidence exists and identify gaps in knowledge to guide future research. Finally, since focal ischemic injury (with or without reperfusion) leading to myocardial infarction is predominantly an atherosclerotic disease of the elderly, this review focuses specifically on septic shock and global ischemia-reperfusion injury occurring after resuscitation from cardiac arrest.

The utility of brain natriuretic peptides in septic shock as markers for mortality and cardiac dysfunction: A systematic review

OBJECTIVE

To conduct a systematic review evaluating the utility of brain natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) as biomarkers in adult patients with septic shock.

MATERIALS AND METHODS

Pubmed/Medline databases were searched from inception to November 2018 using the search terms: (septic[Title/Abstract] AND shock[Title/Abstract]) AND bnp[Title/Abstract]) and (septic[Title/Abstract]) AND shock[Title/Abstract]) AND natriuretic[Title/Abstract]). No restriction was applied regarding date of publication. Comparative observational studies evaluating BNP and NT-proBNP in patients with septic shock aged ≥18 years were eligible for inclusion. Bibliographies from the extracted articles were also reviewed to identify additional relevant publications.

RESULTS

In total, 46 studies met all eligibility criteria and were included. A strong body of literature has demonstrated that in patients with septic shock, increased values of BNP and NT-proBNP are associated with increased mortality. An increase from baseline BNP values has also been associated with increased mortality, whereas decreases from baseline values are not related to worse outcome. Brain natriuretic peptides have also been associated with cardiac dysfunction in patients with sepsis. Moreover, BNP values have been found to be significantly elevated in septic shock, regardless of cardiac dysfunction, and have been used to distinguish between septic and cardiogenic shock. Furthermore, BNP and NT-proBNP are significantly increased in patients with septic shock, compared to patients with sepsis and severe sepsis.

CONCLUSIONS

BNP and NT-proBNP appear to be reliable predictors of outcome in septic shock.

Circulating secretoneurin concentrations in patients with moderate to severe aortic stenosis

BACKGROUND

Secretoneurin (SN) concentrations provide important prognostic information in patients with myocardial dysfunction. Whether preoperative SN concentrations improve risk assessment in patients with moderate to severe aortic stenosis (AS) is unknown.

METHODS

We included 57 patients with moderate to severe AS referred for presurgical evaluation. All patients were examined with comprehensive echocardiography, electrocardiogram (ECG), and biochemical measurements and compared to 10 age- and sex-matched healthy subjects.

RESULTS

Median (quartile 1-3) SN concentrations were 141 (121-163) pmol/L in AS patients and 132 (106-148) pmol/L in control subjects (p = .17). Lower estimated creatinine clearance and use of diuretics, but not standard ECG or echocardiographic indices and cardiac biomarkers, were associated with increasing SN concentrations. Fifteen patients (26%) died during 3.5 years median follow-up. SN concentrations were higher in non-survivors than survivors: 156 (133-209) vs. 140 (116-155) pmol/L, p = .007. Higher SN concentrations were associated with increased risk of mortality also after adjustment for established risk indices, biomarkers, and status regarding valvular surgery: hazard ratio per _lnSN 15.13 (95% CI 1.05-219.00); p = .046. Receiver operating characteristics area under the curve for SN to predict mortality was 0.74 (95% CI 0.60-0.88) compared to 0.73 (0.59-0.87) for high-sensitivity cardiac troponin T and 0.67 (0.51-0.82) for N-terminal pro-B-type natriuretic peptide. The previously identified cut-off of SN >204 pmol/L in cardiac surgical patients predicted mortality also in this cohort.

CONCLUSIONS

SN concentrations improve risk assessment in patients with moderate to severe AS by providing additional prognostic information to established risk indices such as echocardiography, ECG, and established cardiac biomarkers.

Sepsis-induced myocardial dysfunction

PURPOSE OF REVIEW

Sepsis leads to a complex intramyocardial inflammatory response that results in sepsis-induced myocardial dysfunction. Here, recent findings are reviewed in a physiologic context.

RECENT FINDINGS

Decreased systolic contractility during sepsis limits ventricular ejection and stroke volume. Initially, this effect is compensated for by increased diastolic filling during volume resuscitation. Reduced afterload due to arterial vasodilation also compensates so that cardiac output can be maintained or increased. Recent results recognize the importance of diastolic dysfunction, reduced ventricular diastolic compliance that impedes ventricular filling. Diastolic dysfunction becomes increasingly important as severity of septic shock increases. When impaired ventricular ejection is coupled with limited diastolic filling, stroke volume must decrease. Accordingly, diastolic dysfunction is more closely related to mortality than systolic dysfunction. Recent trials of beta-adrenergic agonists and levosimendan have been disappointing, while approaches to modulating the intramyocardial inflammatory response show promise.

SUMMARY

Sepsis-induced myocardial dysfunction is increasingly recognized as a major contributor to outcome of septic shock. Significant strides have been made in understanding the intramyocardial inflammatory response that causes myocardial dysfunction. A number of novel approaches show promise by modulating the intramyocardial inflammatory response.