Clinical significance of lactate in acute cardiac patients

Validation of a biomarker-based mortality score for cardiogenic shock patients: Comparison with a clinical risk score

AIMS

Cardiogenic shock (CS) is the deadliest manifestation of acute heart failure, with persistently high mortality rates and a lack of recent therapeutic breakthroughs. Accurate risk prediction is crucial in clinical decision-making and the design of future clinical trials. We aimed to validate the CLIP score, a biomarker-based risk score comprising cystatin C, lactate, interleukin-6 and NT-proBNP, for predicting mortality in acute coronary syndrome (ACS) related CS, and to compare its predictive value with the previously published CardShock risk score.

METHODS AND RESULTS

The study is a post hoc analysis of the CardShock Study, a prospective, observational European multicentre study on CS. The CLIP score was calculated 12 h after hospital admission, and its ability to predict 90-day mortality was assessed using are under the curve (AUC) of the receiver-operating characteristics (ROC) curve analysis. The discriminative ability of the CLIP score was compared with the CardShock risk score by comparing the AUC's. The cohort was dichotomized into low and high risk groups by the optimal cut-off value derived from the ROC analysis of the CLIP score. Kaplan-Meier curves were constructed to evaluate risk stratification when combining the CLIP and CardShock risk scores. The cohort (n = 121) comprised 77% (n = 93) men and the median age was 67 years (IQR 61-76). A total of 21% (n = 25) of the patients had non-ACS related CS. The CLIP score demonstrated appropriate predictive accuracy for 90-day mortality (AUC 0.84, 95% CI 0.77-0.91), comparable with the CardShock risk score (AUC 0.77 [95% CI 0.69-0.85]; P = 0.064 for comparison). A CLIP score cut-off of 0.28 stratified patients into high risk (65% mortality) and low risk (16% mortality) groups. In addition, incorporating the CLIP score enhanced risk stratification in all CardShock risk score categories.

CONCLUSIONS

The CLIP score, calculated within 12 h of hospital admission, accurately predicted 90-day mortality in CS and complemented the CardShock risk score. The biomarker-based score has potential utility in dynamic mortality risk assessment and could inform clinical management and trial design.

Relationship of serum phosphorus level with acute cerebrovascular disease

There are no sufficient studies on laboratory parameters associated with acute stroke. Laboratory parameters associated with acute stroke may become important in the prevention or follow-up of the disease. To investigate the relationship between cerebrovascular disease (CVD) and serum phosphorus levels. This study was conducted prospectively to evaluate the relationship between cerebrovascular disease and phosphorus in patients who applied to the Emergency Medicine Clinic of the Faculty of Medicine Hospital and underwent central imaging between March 1, 2023, and December 31, 2023. 299 patients who applied to the university emergency department were prospectively included in the study with brain computed tomography (CT) and diffusion magnetic resonance imaging (MRI). The lactate, white blood cell, hgb, neutrophil, lymphocyte, urea, creatine and phosphorus values ​​of the patients at their first admission were recorded. The patients were divided into two groups: CVD group and control group. The laboratory parameters of the patients were compared according to the groups. In the ROC analysis performed to evaluate the power of laboratory parameters in predicting the diagnosis of CVD, the AUC value of phosphorus was obtained as 0.935, lactate as 0.620 and urea as 0.596. The optimum cut-off value for phosphorus was calculated as 3.47 (mg/dl) and the sensitivity of this cut-off value was found to be 89%, specifically 86.9%, positive predictive value (ppv) as 77.4% and negative predictive value (npv) as 94%. Lactate, urea and phosphorus values were found to be significantly higher in the CVD group compared to the control group. With this study, we found that serum phosphorus levels were higher than our cut-off value in patients with acute ischemic CVD. We believe that serum phosphorus level will be useful in excluding acute cerebrovascular disease due to its high negative predictive value when evaluated according to the cut-off value of 3.47 (mg/dl).

The denitrosylase SCoR2 controls cardioprotective metabolic reprogramming

Acute myocardial infarction (MI) is a leading cause of morbidity and mortality, and therapeutic options remain limited. Endogenously generated nitric oxide (NO) is highly cardioprotective, but protection is not replicated by nitroso-vasodilators (e.g., nitrates, nitroprusside) used in clinical practice, highlighting specificity in NO-based signaling and untapped therapeutic potential. Signaling by NO is mediated largely by S-nitrosylation, entailing specific enzymes that form and degrade S-nitrosothiols in proteins (SNO-proteins), termed nitrosylases and denitrosylases, respectively. SNO-CoA Reductase 2 (SCoR2; product of the Akr1a1 gene) is a recently discovered protein denitrosylase. Genetic variants in SCoR2 have been associated with cardiovascular disease, but its function is unknown. Here we show that mice lacking SCoR2 exhibit robust protection in an animal model of MI. SCoR2 regulates ketolytic energy availability, antioxidant levels and polyol homeostasis via S-nitrosylation of key metabolic effectors. Human cardiomyopathy shows reduced SCoR2 expression and an S-nitrosylation signature of metabolic reprogramming, mirroring SCoR2-/- mice. Deletion of SCoR2 thus coordinately reprograms multiple metabolic pathways-ketone body utilization, glycolysis, pentose phosphate shunt and polyol metabolism-to limit infarct size, establishing SCoR2 as a novel regulator in the injured myocardium and a potential drug target.

Impact statement

Mice lacking the denitrosylase enzyme SCoR2/AKR1A1 demonstrate robust cardioprotection resulting from reprogramming of multiple metabolic pathways, revealing widespread, coordinated metabolic regulation by SCoR2.

A wearable platform for biochemical sweat analysis using photonic crystal hydrogel

Wearable systems for health monitoring are highly desired in personal diagnostics and precision medicine while challenges remain in constructing such wearable systems with reliability and high performance. Herein, we report a wearable platform for non-invasive monitoring biomarkers in sweat. The device is composed of a butterfly-shaped like microfluidic platform in which responsive photonic crystal hydrogels are embedded in each butterfly wing as sensors. Sweat lactate concentration and pH can be obtained via the color variation of the sensor with naked eyes. Accurate quantitative analysis of the two target analytes can be obtained via the image analysis on a mobile phone by integrating the linear range response to analytes within the physiological range. Moreover, the sensor exhibits good reproducibility, excellent selectivity and long-term stability. On-body trials have been conducted by attaching the device on volunteers' body, and the obtained results are consistent with those analyzed through standardized methods, demonstrating its potentiality in real-time and continuous monitoring sweat biomarkers. This non-invasive wearable sensor provides a new strategy for personal health monitoring and sports performance assessment.

CNDP2: An Enzyme Linking Metabolism and Cardiovascular Diseases?

The heart requires a substantial amount of energy to function, utilising various substrates including lipids, glucose and lactate as energy sources. In times of increased stress, lactate becomes the primary energy source of the heart, but persistently elevated lactate levels are linked to poor patient outcomes and increased mortality. Recently, carnosine dipeptidase II (CNDP2) was discovered to catalyse the formation of Lac-Phe, an exercise-induced metabolite derived from lactate, which has been shown to suppress appetite in mice and reduce adipose tissue in humans. This review discusses CNDP2, including its role in lactate clearance, carnosine hydrolysis, oxidative stress regulation, and involvement in metabolite regulation. The association between CNDP2 and cardiometabolic and renal diseases is also explored, and knowledge gaps are highlighted. CNDP2 appears to be a complex participant in human physiological processes and disease, necessitating additional research to unveil its functions and potential therapeutic applications.

Preadmission metformin use increased the incidence of hyperlactatemia at admission and 30-day in-hospital mortality among T2D patients with heart disease at high risk of hypoxia

BACKGROUND

Surprisingly, despite the high prevalence of metformin use in type 2 diabetes (T2D) patients with heart disease, limited safety data is available regarding metformin use in patients with acute and critical heart disease.

METHODS

In this single-center retrospective study, patients admitted to the cardiology department for heart failure (HF) or acute coronary syndrome (ACS) between December 2013 and December 2021 and who underwent arterial blood gas analysis at admission with an estimated glomerular clearance rate of ≥45 ml/min/1.73 m2 were identified. The incidences of hyperlactatemia, acidosis, and 30-day in-hospital mortality were compared between preadmission metformin users and nonusers.

RESULTS

Of 526 admissions, 193/193 metformin users/nonusers were selected in a propensity score-matched model. Metformin users had greater lactate levels (2.55 ± 2.07 mmol/l vs. 2.00 ± 1.80 mmol/l P < 0.01), a greater incidence of hyperlactatemia [odds ratio (OR) = 2.55; 95% confidence interval (CI), 1.63-3.98; P < 0.01] and acidosis (OR = 1.78; 95% CI, 1.00-3.16; P < 0.05) at admission and a greater incidence of in-hospital mortality (OR = 3.83; 95% CI, 1.05-13.94; P < 0.05), especially those with HF/acute myocardial infarction, elderly age, or without preadmission insulin use.

CONCLUSIONS

Our results suggest that, compared to metformin nonusers, preadmission use of metformin may be associated with a greater incidence of hyperlactatemia and acidosis at admission and greater 30-day in-hospital mortality among T2D patients with HF or ACS at high risk of hypoxia, particularly those without preadmission insulin use. The safety of metformin in this population needs to be confirmed in prospective controlled trials.

A novel echocardiographic parameter considering left ventricular afterload during V-A ECMO support

BACKGROUND

Left ventricular stroke work index (LVSWI) and cardiac power index (CPI) account for the haemodynamic load of the left ventricle and are promising prognostic values in cardiogenic shock. However, accurately and non-invasively measuring these parameters during veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is challenging and potentially biased by the extracorporeal circulation. This study aimed to investigate, in an ovine model of cardiogenic shock, whether Pressure-Strain Product (PSP), a novel speckle-tracking echocardiography parameter, (1) can correlate with pressure-volume catheter-based LVSWI and CPI, and (2) can be load-independent during the flow modification of V-A ECMO.

METHODS

Nine Dorset-cross ewes (51 ± 4 kg) were included. After cardiogenic shock was induced, full support V-A ECMO (X L/min based on 60 mL/kg/min) commenced. At seven time points during 24-h observation, echocardiographic parameters as well as pressure-volume catheter-based LVSWI and CPI were simultaneously measured with X and following X-1 L/min of ECMO flow. PSP was calculated by multiplying global circumferential strain or global radial strain, and mean arterial pressure, for PSPcirc or PSPrad, respectively.

RESULTS

PSPcirc showed a stronger correlation with LVSWI (correlation coefficient, CC = .360, p < .001) and CPI (CC = .283, p < .001) than other echocardiographic parameters. The predictability of PSPcirc for pressure-volume catheter-based LVSWI (AUC .82) and CPI (AUC .80) was also higher than other echocardiographic parameters. No statistically significant differences were identified between the two ECMO flow variations in PSPcirc (p = .558).

CONCLUSIONS

A novel echocardiographic parameter, PSP, may non-invasively predict pressure-volume catheter-based LVSWI and CPI in a load-independent manner in a cardiogenic shock supported by V-A ECMO.

Smart solutions in hypertension diagnosis and management: a deep dive into artificial intelligence and modern wearables for blood pressure monitoring

Hypertension, a widespread cardiovascular issue, presents a major global health challenge. Traditional diagnosis and treatment methods involve periodic blood pressure monitoring and prescribing antihypertensive drugs. Smart technology integration in healthcare offers promising results in optimizing the diagnosis and treatment of various conditions. We investigate its role in improving hypertension diagnosis and treatment effectiveness using machine learning algorithms for early and accurate detection. Intelligent models trained on diverse datasets (encompassing physiological parameters, lifestyle factors, and genetic information) to detect subtle hypertension risk patterns. Adaptive algorithms analyze patient-specific data, optimizing treatment plans based on medication responses and lifestyle habits. This personalized approach ensures effective, minimally invasive interventions tailored to each patient. Wearables and smart sensors provide real-time health insights for proactive treatment adjustments and early complication detection.

Relationship between lactate and thiamine-responsive disorders in hospitalised infants and children in Lao PDR: secondary analysis of a prospective cohort study

BACKGROUND

Lactate is a by-product of thiamine-deficient cellular metabolism, and hyperlactataemia can indicate severe illness. However, little is known about the clinical significance of hyperlactataemia in thiamine deficiency disorders.

AIM

To describe the relationship between whole-blood lactate level and thiamine-responsive disorders (TRDs) in children with signs/symptoms of thiamine deficiency in a high-risk region.

METHODS

This is a secondary analysis of data from the Lao Thiamine study, a prospective cohort study which enrolled hospitalised infants and children (aged 21 days to <18 months) who had at least one sign or symptom suggestive of thiamine deficiency in Lao PDR. Therapeutic thiamine was administered, and clinical evaluations were completed at several time-points over the next 72 h. Three paediatricians reviewed individual case reports to evaluate clinical response to thiamine and assigned TRD status. Data from 402 children were analysed by logistic regression and predictive modelling to examine the relationship between hyperlactataemia and TRDs.

RESULTS

Baseline hyperlactataemia (lactate >4.0 mmol/L) was associated with an increased odds of clinical improvement after thiamine administration [OR (95% CI) 2.32 (1.28-4.45), p = 0.007]. Baseline hyperlactataemia was a significant predictor of thiamine deficiency (thiamine diphosphate <40 nmol/L) [area under the receiver operating curve (95% CI) 0.76 (0.67-0.84), p < 0.001], and increased odds of mortality [OR (95% CI) 3.51 (1.38-8.94), p = 0.009].

CONCLUSIONS

In children with signs/symptoms of thiamine deficiency, hyperlactataemia is associated with a favourable clinical response to thiamine, biochemical thiamine deficiency, and increased odds of mortality. Lactate may be useful in identifying children who might benefit from therapeutic thiamine.

An Integrated Approach Based on Clinical Data Combined with Metabolites and Biomarkers for the Assessment of Post-Operative Complications after Cardiac Surgery

Background: Early diagnosis of post-operative complications is an urgent task, allowing timely prescribing of appropriate therapy and reducing the cost of patient treatment. The purpose of this study was to determine whether an integrated approach based on clinical data, along with metabolites and biomarkers, had greater predictive value than the models built on fewer data in the early diagnosis of post-operative complications after cardiac surgery. Methods: The study included patients (n = 62) admitted for planned cardiac surgery (coronary artery bypass grafting with cardiopulmonary bypass) with (n = 26) or without (n = 36) post-operative complications. Clinical and laboratory data on the first day after surgery were analyzed. Additionally, patients' blood samples were collected before and on the first day after surgery to determine biomarkers and metabolites. Results: Multivariate PLS-DA models, predicting the presence or absence of post-operative complications, were built using clinical data, concentrations of metabolites and biomarkers, and the entire data set (ROC-AUC = 0.80, 0.71, and 0.85, respectively). For comparison, we built univariate models using the EuroScore2 and SOFA scales, concentrations of lactate, the dynamic changes of 4-hydroxyphenyllactic acid, and the sum of three sepsis-associated metabolites (ROC-AUC = 0.54, 0.79, 0.62, 0.58, and 0.70, respectively). Conclusions: The proposed complex model using the entire dataset had the best characteristics, which confirms the expediency of searching for new predictive models based on a variety of factors.

Blood glucose and lactate levels as early predictive markers in patients presenting with cardiogenic shock: A retrospective cohort study

Lactate and glucose are widely used biochemical parameters in current predictive risk scores for cardiogenic shock. Data regarding the relationship between lactate and glucose levels in cardiogenic shock are limited. Thus, we aimed to analyze glucose and lactate as early markers for in-hospital mortality in cardiogenic shock. In this retrospective cohort study, 312 patients presenting with cardiogenic shock to a tertiary-care hospital between 2016 and 2018 were included. Apparent cardiogenic shock was defined as hypoperfusion with hemodynamic compromise and biochemical marker increase due to diminished tissue perfusion, corresponding to SCAI shock stages. In-hospital mortality was assessed as the primary endpoint. The median age of the study population was 71 (60-79) years and the etiology of cardiogenic shock was acute myocardial infarction in 45.8%. Overall in-hospital mortality was 67.6%. In the receiver operating curve analysis, the area under the receiver-operating curve (AUC) for prediction of in-hospital mortality was higher for lactate (AUC: 0.757) than for glucose (AUC: 0.652). Both values were significantly associated with outcome (groups created with best cutoff values obtained from the Youden index). Correlation analysis showed a significant non-linear association of both values. In a multivariable stepwise Cox regression analysis, lactate remained an independent predictor for in-hospital mortality, whilst glucose, despite being implicated in energy metabolism, was not independently predictive for mortality. Together, these data suggest that lactate at admission is superior for mortality prediction in patients with apparent cardiogenic shock. Glucose was not independently predictive for mortality.

Hypothermic and cryogenic preservation of cardiac tissue-engineered constructs

Cardiac tissue engineering (cTE) has already advanced towards the first clinical trials, investigating safety and feasibility of cTE construct transplantation in failing hearts. However, the lack of well-established preservation methods poses a hindrance to further scalability, commercialization, and transportation, thereby reducing their clinical implementation. In this study, hypothermic preservation (4 °C) and two methods for cryopreservation (i.e., a slow and fast cooling approach to -196 °C and -150 °C, respectively) were investigated as potential solutions to extend the cTE construct implantation window. The cTE model used consisted of human induced pluripotent stem cell-derived cardiomyocytes and human cardiac fibroblasts embedded in a natural-derived hydrogel and supported by a polymeric melt electrowritten hexagonal scaffold. Constructs, composed of cardiomyocytes of different maturity, were preserved for three days, using several commercially available preservation protocols and solutions. Cardiomyocyte viability, function (beat rate and calcium handling), and metabolic activity were investigated after rewarming. Our observations show that cardiomyocytes' age did not influence post-rewarming viability, however, it influenced construct function. Hypothermic preservation with HypoThermosol® ensured cardiomyocyte viability and function. Furthermore, fast freezing outperformed slow freezing, but both viability and function were severely reduced after rewarming. In conclusion, whereas long-term preservation remains a challenge, hypothermic preservation with HypoThermosol® represents a promising solution for cTE construct short-term preservation and potential transportation, aiding in off-the-shelf availability, ultimately increasing their clinical applicability.

Non-invasive pulse arrival time is associated with cardiac index in pediatric heart transplant patients with normal ejection fraction

Objective.Cardiac Index (CI) is a key physiologic parameter to ensure end organ perfusion in the pediatric intensive care unit (PICU). Determination of CI requires invasive cardiac measurements and is not routinely done at the PICU bedside. To date, there is no gold standard non-invasive means to determine CI. This study aims to use a novel non-invasive methodology, based on routine continuous physiologic data, called Pulse Arrival Time (PAT) as a surrogate for CI in patients with normal Ejection Fraction (EF).Approach.Electrocardiogram (ECG) and photoplethysmogram (PPG) signals were collected from beside monitors at a sampling frequency of 250 samples per second. Continuous PAT, derived from the ECG and PPG waveforms was averaged per patient. Pearson's correlation coefficient was calculated between PAT and CI, PAT and heart rate (HR), and PAT and EF.Main Results.Twenty patients underwent right heart cardiac catheterization. The mean age of patients was 11.7 ± 5.4 years old, ranging from 11 months old to 19 years old, the median age was 13.4 years old. HR in this cohort was 93.8 ± 17.0 beats per minute. The average EF was 54.4 ± 9.6%. The average CI was 3.51 ± 0.72 l min-1m-2, with ranging from 2.6 to 4.77 l min-1m-2. The average PAT was 0.31 ± 0.12 s. Pearson correlation analysis showed a positive correlation between PAT and CI (0.57,p< 0.01). Pearson correlation between HR and CI, and correlation between EF and CI was 0.22 (p= 0.35) and 0.03 (p= 0.23) respectively. The correlation between PAT, when indexed by HR (i.e. PAT × HR), and CI minimally improved to 0.58 (p< 0.01).Significance.This pilot study demonstrates that PAT may serve as a valuable surrogate marker for CI at the bedside, as a non-invasive and continuous modality in the PICU. The use of PAT in clinical practice remains to be thoroughly investigated.

Normalized lactate load as an independent prognostic indicator in patients with cardiogenic shock

BACKGROUND

Early prognosis evaluation is crucial for decision-making in cardiogenic shock (CS) patients. Dynamic lactate assessment, for example, normalized lactate load, has been a better prognosis predictor than single lactate value in septic shock. Our objective was to investigate the correlation between normalized lactate load and in-hospital mortality in patients with CS.

METHODS

Data were extracted from the Medical Information Mart for Intensive Care (MIMIC)-IV database. The calculation of lactate load involved the determination of the cumulative area under the lactate curve, while normalized lactate load was computed by dividing the lactate load by the corresponding period. Receiver Operating Characteristic (ROC) curves were constructed, and the evaluation of areas under the curves (AUC) for various parameters was performed using the DeLong test.

RESULTS

Our study involved a cohort of 1932 CS patients, with 687 individuals (36.1%) experiencing mortality during their hospitalization. The AUC for normalized lactate load demonstrated significant superiority compared to the first lactate (0.675 vs. 0.646, P < 0.001), maximum lactate (0.675 vs. 0.651, P < 0.001), and mean lactate (0.675 vs. 0.669, P = 0.003). Notably, the AUC for normalized lactate load showed comparability to that of the Sequential Organ Failure Assessment (SOFA) score (0.675 vs. 0.695, P = 0.175).

CONCLUSION

The normalized lactate load was an independently associated with the in-hospital mortality among CS patients.

Hyperlactatemia and poor outcome After postcardiotomy veno-arterial extracorporeal membrane oxygenation: An individual patient data meta-Analysis

INTRODUCTION

Postcardiotomy veno-arterial extracorporeal membrane oxygenation (V-A-ECMO) is associated with significant mortality. Identification of patients at very high risk for death is elusive and the decision to initiate V-A-ECMO is based on clinical judgment. The prognostic impact of pre-V-A-ECMO arterial lactate level in these critically ill patients has been herein evaluated.

METHODS

A systematic review was conducted to identify studies on postcardiotomy VA-ECMO for the present individual patient data meta-analysis.

RESULTS

Overall, 1269 patients selected from 10 studies were included in this analysis. Arterial lactate level at V-A-ECMO initiation was increased in patients who died during the index hospitalization compared to those who survived (9.3 vs 6.6 mmol/L, p < 0.0001). Accordingly, in hospital mortality increased along quintiles of pre-V-A-ECMO arterial lactate level (quintiles: 1, 54.9%; 2, 54.9%; 3, 67.3%; 4, 74.2%; 5, 82.2%, p < 0.0001). The best cut-off for arterial lactate was 6.8 mmol/L (in-hospital mortality, 76.7% vs. 55.7%, p < 0.0001). Multivariable multilevel mixed-effect logistic regression model including arterial lactate level significantly increased the area under the receiver operating characteristics curve (0.731, 95% CI 0.702-0.760 vs 0.679, 95% CI 0.648-0.711, DeLong test p < 0.0001). Classification and regression tree analysis showed the in-hospital mortality was 85.2% in patients aged more than 70 years with pre-V-A-ECMO arterial lactate level ≥6.8 mmol/L.

CONCLUSIONS

Among patients requiring postcardiotomy V-A-ECMO, hyperlactatemia was associated with a marked increase of in-hospital mortality. Arterial lactate may be useful in guiding the decision-making process and the timing of initiation of postcardiotomy V-A-ECMO.

Cardiac lipotoxicity and fibrosis underlie impaired contractility in a mouse model of metabolic dysfunction-associated steatotic liver disease

The leading cause of death among patients with metabolic dysfunction-associated steatotic liver disease (MASLD) is cardiovascular disease. A significant percentage of MASLD patients develop heart failure driven by functional and structural alterations in the heart. Previously, we observed cardiac dysfunction in hepatocyte-specific peroxisome proliferator-activated receptor alpha knockout (Ppara HepKO), a mouse model that exhibits hepatic steatosis independent of obesity and insulin resistance. The goal of the present study was to determine mechanisms that underlie hepatic steatosis-induced cardiac dysfunction in Ppara HepKO mice. Experiments were performed in 30-week-old Ppara HepKO and littermate control mice fed regular chow. We observed decreased cardiomyocyte contractility (0.17 ± 0.02 vs. 0.24 ± 0.02 μm, p < 0.05), increased cardiac triglyceride content (0.96 ± 0.13 vs. 0.68 ± 0.06 mM, p < 0.05), collagen type 1 (4.65 ± 0.25 vs. 0.31 ± 0.01 AU, p < 0.001), and collagen type 3 deposition (1.32 ± 0.46 vs. 0.05 ± 0.03 AU, p < 0.05). These changes were associated with increased apoptosis as indicated by terminal deoxynucleotidyl transferase dUTP nick end labeling staining (30.9 ± 4.7 vs. 13.1 ± 0.8%, p < 0.006) and western blots showing increased cleaved caspase-3 (0.27 ± 0.006 vs. 0.08 ± 0.01 AU, p < 0.003) and pro-caspase-3 (5.4 ± 1.5 vs. 0.5 ± 0.3 AU, p < 0.02), B-cell lymphoma protein 2-associated X (0.68 ± 0.07 vs. 0.04 ± 0.04 AU, p < 0.001), and reduced B-cell lymphoma protein 2 (0.29 ± 0.01 vs. 1.47 ± 0.54 AU, p < 0.05). We further observed elevated circulating natriuretic peptides and exercise intolerance in Ppara HepKO mice when compared to controls. Our data demonstrated that lipotoxicity, and fibrosis underlie cardiac dysfunction in MASLD.

Dynamics of serum anion gaps with in-hospital mortality: Analysis of the multi-open databases

BACKGROUND

Few studies have investigated the relationship between the anion gap, including the corrected anion gap, and patient mortality in intensive care units (ICUs) without restricting the analysis to specific diseases or medical specialties. Our primary objective was to investigate the association between the anion gap and ICU mortality using multiple open-access databases.

METHODS

We identified 4229 subjects from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database, whose entries were from between 2008 and 2019. For each patient, the anion gap and corrected anion gap were calculated, and the study sample was divided into tertile groups (T) according to these levels. The association between the anion gap and in-hospital mortality was assessed using hazard ratios (HRs) and 95% confidence intervals (CIs) derived from a multivariable-adjusted Cox proportional hazards model. Besides MIMIC-IV, we also incorporated study samples from two other databases (MIMIC-III and electronic ICU) to calculate summary HRs using a random-effects meta-analysis.

RESULTS

Within MIMIC-IV, 1015 patients (24%) died during an average follow-up period of 15.5 days. The fully adjusted HRs and 95% CIs for T2 and T3, relative to T1, were 1.31 (95% CI 1.08-1.58) and 1.54 (95% CI 1.24-1.90), respectively. When grouped by corrected anion gap, the results remained statistically significant. In the meta-analysis, the summary HRs and 95% CIs for T2 and T3 were 1.24 (95% CI 1.08-1.43) and 1.55 (95% CI 1.33-1.82), respectively.

CONCLUSIONS

Both the anion gap and corrected anion gap were associated with in-hospital mortality regardless of specific diseases or medical specialties.

A miniaturized culture platform for control of the metabolic environment

The heart is a metabolic "omnivore" and adjusts its energy source depending on the circulating metabolites. Human cardiac organoids, a three-dimensional in vitro model of the heart wall, are a useful tool to study cardiac physiology and pathology. However, cardiac tissue naturally experiences shear stress and nutrient fluctuations via blood flow in vivo, whilst in vitro models are conventionally cultivated in a static medium. This necessitates the regular refreshing of culture media, which creates acute cellular disturbances and large metabolic fluxes. To culture human cardiac organoids in a more physiological manner, we have developed a perfused bioreactor for cultures in a 96-well plate format. The designed bioreactor is easy to fabricate using a common culture plate and a 3D printer. Its open system allows for the use of traditional molecular biology techniques, prevents flow blockage issues, and provides easy access for sampling and cell assays. We hypothesized that a perfused culture would create more stable environment improving cardiac function and maturation. We found that lactate is rapidly produced by human cardiac organoids, resulting in large fluctuations in this metabolite under static culture. Despite this, neither medium perfusion in bioreactor culture nor lactate supplementation improved cardiac function or maturation. In fact, RNA sequencing revealed little change across the transcriptome. This demonstrates that cardiac organoids are robust in response to fluctuating environmental conditions under normal physiological conditions. Together, we provide a framework for establishing an easily accessible perfusion system that can be adapted to a range of miniaturized cell culture systems.

Prognosis of patients with extreme acidosis on admission to the emergency department: A retrospective cohort study

AIM OF THE STUDY

The development of acidosis in critically ill patients is considered to be a negative prognostic factor, and when extreme, even incompatible with life. We aimed to test the prognosis of patients with a pH lower than 6.9 on emergency department admission.

METHODS

A retrospective cohort study in adult patients admitted to two emergency departments with a pH < 6.9 during the first 12 h of admission. Primary outcome was mortality within 24 h from emergency department admission. We performed a regression analysis of clinical and laboratory data in order to identify factors associated with mortality in this population.

RESULTS

We analyzed data of 206 admissions to the emergency departments between 2008 and 2018 with extreme acidosis. pH Values ranged from 6.898 to 6.35 (mean 6.8 and median 6.83). 60 (29%) of the patients survived the first 24 h. 35 patients (58%) of those also survived to hospital discharge, and of them 80% have returned to their previous functional status. Patient's age, type of acidosis, cardio-pulmonary resuscitation on arrival, and diagnosis on admission were correlated with survival.

CONCLUSIONS

A small but significant portion of patients with extreme acidosis on emergency department admission survive at least to 24 h and until hospital discharge. The clinical decision making should be based on other prognostic factors rather than pH value by itself.

Fasting plasma lactate as a possible early clinical marker for metabolic disease risk

BACKGROUND AND AIM

Elevated fasting plasma lactate concentrations are evident in individuals with metabolic diseases. However, it has yet to be determined if these associations exist in a young, healthy population as a possible early marker for metabolic disease risk. The purpose of this study was to determine if indices of the metabolic syndrome are related to plasma lactate concentrations in this population.

METHODS

Fifty (29 ± 7 yr) men (n = 19) and women (n = 31) classified as overweight (26.4 ± 1.8 kg/m2) participated in this observational study. Blood pressure and blood metabolites were measured after an overnight fast. Lactate was also measured before and after a three-day eucaloric high-fat (70 %) diet. The homeostatic model assessment for insulin resistance (HOMA-IR) was calculated as a measure of insulin resistance. Visceral adipose tissue mass was determined via dual X-ray absorptiometry.

RESULTS

Triglycerides (r = 0.55, p=<0.0001), HOMA-IR (r = 0.53, p=<0.0001), and systolic and diastolic (both, r = 0.36, p = 0.01) blood pressures associated with fasting plasma lactate. No differences in visceral adipose tissue existed between the sexes (p = 0.41); however, the relationship between visceral adipose tissue and lactate existed only in females (r = 0.59, p = 0.02) but not in males (p = 0.53). Fasting lactate and HOMA-IR increased in males (p = 0.01 and p = 0.02, respectively), but not females, following a three-day high-fat diet.

CONCLUSION

Indices of the metabolic syndrome associated with fasting plasma lactates in young relatively healthy individuals. Fasting lactate also increased in a sex-specific manner after a three-day high fat diet. Thus, lactate could become a clinical marker for metabolic disease risk.

Biodegradable, Biocompatible, and Implantable Multifunctional Sensing Platform for Cardiac Monitoring

Cardiac monitoring after heart surgeries is crucial for health maintenance and detecting postoperative complications early. However, current methods like rigid implants have limitations, as they require performing second complex surgeries for removal, increasing infection and inflammation risks, thus prompting research for improved sensing monitoring technologies. Herein, we introduce a nanosensor platform that is biodegradable, biocompatible, and integrated with multifunctions, suitable for use as implants for cardiac monitoring. The device has two electrochemical biosensors for sensing lactic acid and pH as well as a pressure sensor and a chemiresistor array for detecting volatile organic compounds. Its biocompatibility with myocytes has been tested in vitro, and its biodegradability and sensing function have been proven with ex vivo experiments using a three-dimensional (3D)-printed heart model and 3D-printed cardiac tissue patches. Moreover, an artificial intelligence-based predictive model was designed to fuse sensor data for more precise health assessment, making it a suitable candidate for clinical use. This sensing platform promises impactful applications in the realm of cardiac patient care, laying the foundation for advanced life-saving developments.

Preoperative arterial lactate and outcome after surgery for type A aortic dissection: The ERTAAD multicenter study

Background

Acute type A aortic dissection (TAAD) is associated with significant mortality and morbidity. In this study we evaluated the prognostic significance of preoperative arterial lactate concentration on the outcome after surgery for TAAD.

Methods

The ERTAAD registry included consecutive patients who underwent surgery for acute type A aortic dissection (TAAD) at 18 European centers of cardiac surgery.

Results

Data on arterial lactate concentration immediately before surgery were available in 2798 (71.7 %) patients. Preoperative concentration of arterial lactate was an independent predictor of in-hospital mortality (mean, 3.5 ± 3.2 vs 2.1 ± 1.8 mmol/L, adjusted OR 1.181, 95%CI 1.129-1.235). The best cutoff value preoperative arterial lactate concentration was 1.8 mmol/L (in-hospital mortality, 12.0 %, vs. 26.6 %, p < 0.0001). The rates of in-hospital mortality increased along increasing quintiles of arterial lactate and it was 12.1 % in the lowest quintile and 33.6 % in the highest quintile (p < 0.0001). The difference between multivariable models with and without preoperative arterial lactate was statistically significant (p = 0.0002). The NRI was 0.296 (95%CI 0.200-0.391) (p < 0.0001) with -17 % of events correctly reclassified (p = 0.0002) and 46 % of non-events correctly reclassified (p < 0.0001). The IDI was 0.025 (95%CI 0.016-0.034) (p < 0.0001). Six studies from a systematic review plus the present one provided data for a pooled analysis which showed that the mean difference of preoperative arterial lactate between 30-day/in-hospital deaths and survivors was 1.85 mmol/L (95%CI 1.22-2.47, p < 0.0001, I2 64 %).

Conclusions

Hyperlactatemia significantly increased the risk of mortality after surgery for acute TAAD and should be considered in the clinical assessment of these critically ill patients.

HiSorb sorptive extraction for determining salivary short chain fatty acids and hydroxy acids in heart failure patients

Variations in salivary short-chain fatty acids and hydroxy acids (e.g., lactic acid, and 3-hydroxybutyric acid) levels have been suggested to reflect the dysbiosis of human gut microbiota, which represents an additional factor involved in the onset of heart failure (HF) disease. The physical-chemical properties of these metabolites combined with the complex composition of biological matrices mean that sample pre-treatment procedures are almost unavoidable. This work describes a reliable, simple, and organic solvent free protocol for determining short-chain fatty acids and hydroxy acids in stimulated saliva samples collected from heart failure, obese, and hypertensive patients. The procedure is based on in-situ pentafluorobenzyl bromide (PFB-Br) derivatization and HiSorb sorptive extraction coupled to thermal desorption and gas chromatography-tandem mass spectrometry. The HiSorb extraction device is completely compatible with aqueous matrices, thus saving on time and materials associated with organic solvent-extraction methods. A Central Composite Face-Centred experimental design was used for the optimization of the molar ratio between PFB-Br and target analytes, the derivatization temperature, and the reaction time which were 100, 60 °C, and 180 min, respectively. Detection limits in the range 0.1-100 µM were reached using a small amount of saliva (20 µL). The use of sodium acetate-1-13C as an internal standard improved the intra- and inter-day precision of the method which ranged from 10 to 23%. The optimized protocol was successfully applied for what we believe is the first time to evaluate the salivary levels of short chain fatty acids and hydroxy acids in saliva samples of four groups of patients: i) patients admitted to hospital with acute HF symptoms, ii) patients with chronic HF symptoms, iii) patients without HF symptoms but with obesity, and iv) patients without HF symptoms but with hypertension. The first group of patients showed significantly higher levels of salivary acetic acid and lactic acid at hospital admission as well as the lowest values of hexanoic acid and heptanoic acid. Moreover, the significant high levels of acetic acid, propionic acid, and butyric acid observed in HF respect to the other patients suggest the potential link between oral bacteria and gut dysbiosis.

Early Recognition and Risk Stratification in Cardiogenic Shock: Well Begun Is Half Done

Cardiogenic shock is a complex syndrome manifesting with distinct phenotypes depending on the severity of the primary cardiac insult and the underlying status. As long as therapeutic interventions fail to divert its unopposed rapid evolution, poor outcomes will continue challenging health care systems. Thus, early recognition in the emergency setting is a priority, in order to avoid delays in appropriate management and to ensure immediate initial stabilization. Since advanced therapeutic strategies and specialized shock centers may provide beneficial support, it seems that directing patients towards the recently described shock network may improve survival rates. A multidisciplinary approach strategy commands the interconnections between the strategic role of the ED in affiliation with cardiac shock centers. This review outlines critical features of early recognition and initial therapeutic management, as well as the utility of diagnostic tools and risk stratification models regarding the facilitation of patient trajectories through the shock network. Further, it proposes the implementation of precise criteria for shock team activation and the establishment of definite exclusion criteria for streaming the right patient to the right place at the right time.

Mortality and prognostic factors in connective tissue disease-associated pulmonary arterial hypertension patients complicated with right heart failure

OBJECTIVE

To identify predictive factors associated with mortality in connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH) patients who were complicated with right heart failure (RHF).

METHODS

In this single-center retrospective study, baseline demographics, clinical features, laboratory results, and hemodynamic assessments were collected. Kaplan-Meier analysis was applied to analyze all-cause mortality. Univariate and forward stepwise multivariate Cox proportional regression analyses were performed to identify independent predictors of mortality.

RESULTS

A total of 51 right heart catheterization-confirmed CTD-PAH patients complicated with RHF were consecutively enrolled in this study from 2012 to 2022. Forty-eight (94%) enrolled patients were female and the mean age was 36.0 ± 11.8 years. Thirty-two (61.5%) were systemic lupus erythematosus-PAH and 33%/67% showed World Health Organization functional class III/IV, respectively. Twenty-five (49%) of those patients died and Kaplan-Meier analysis showed the overall 1-, 3-, and 5-week survival rates from the time of hospitalization as 86.28%, 60.78%, and 56.86%, respectively. RHF in CTD-PAH patients mainly resulted from progression of PAH (n = 19) and infection (n = 5), which also contributed to the leading causes of death. Statistical analysis between survivors and non-survivors showed that death from RHF was associated with higher levels of urea (9.66 vs 6.34 mmol/L, P = 0.002), lactate (cLac: 2.65 vs 1.9 mmol/L, P = 0.006), total bilirubin (23.1 vs 16.9 μmol/L, P = 0.018) and direct bilirubin (10.5 vs 6.5 μmol/L, P = 0.004), but with lower levels of hematocrit (33.7 vs 39, P = 0.004), cNa+ (131 vs 136 mmol/L, P = 0.003). Univariate and forward stepwise multivariate Cox proportional regression analyses indicated that the level of cLac (hazards ratio:1.297; 95% CI: 1.076-1.564; P = 0.006) was an independent risk factor for mortality.

CONCLUSION

The short-term prognosis of CTD-PAH complicated with RHF was very poor, and hyperlactic acidemia (cLac > 2.85 mmoL/L) was an independent predicting factor for mortality of CTD-PAH patients complicated with RHF.

Early Changes in Acute Myocardial Infarction in Pigs: Achieving Early Detection with Wearable Devices

We examined the changes in variables that could be recorded on wearable devices during the early stages of acute myocardial infarction (AMI) in an animal model. Early diagnosis of AMI is important for prognosis; however, delayed diagnosis is common because of patient hesitation and lack of timely evaluations. Wearable devices are becoming increasingly sophisticated in the ability to track indicators. In this study, we retrospectively reviewed the changes in four variables during AMI in a pig model to assess their ability to help predict AMI onset. AMI was created in 33 pigs by 90-min balloon occlusion of the left anterior descending artery. Blood pressure, EKG, and lactate and cardiac troponin I levels were recorded during the occlusion period. Blood pressure declined significantly within 15 min after balloon inflation (mean arterial pressure, from 61 ± 8 to 50 ± 8 mmHg) and remained at this low level. Within 5 min of balloon inflation, the EKG showed ST-elevation in precordial leads V1–V3. Blood lactate levels increased gradually after occlusion and peaked at 60 min (from 1.48 to 2.53 mmol/L). The continuous transdermal troponin sensor demonstrated a gradual increase in troponin levels over time. Our data suggest that significant changes in key indicators (blood pressure, EKG leads V1–V3, and lactate and troponin levels) occurred at the onset of AMI. Monitoring of these variables could be used to develop an algorithm and alert patients early at the onset of AMI with the help of a wearable device.

Arterial lactate as a risk factor for death in respiratory failure related to coronavirus disease 2019: an observational study

BACKGROUND

Arterial lactate is a recognized biomarker associated with death in critically ill patients. The prognostic role of arterial lactate in acute respiratory failure due to the novel coronavirus disease 2019 (COVID-19) is unclear.

OBJECTIVES

We aimed to investigate the prognostic role of arterial lactate levels at admission in patients with COVID-19-related acute respiratory failure.

DESIGN AND METHODS

Cohorts of consecutive patients admitted to nonintensive care units (ICU) at study centers for COVID-19-related respiratory failure were merged into a collaborative database. The prognostic role of lactate levels at admission was assessed for continuous values and values ⩾2.0 mmol/l, and lactate clearance at 24 h through delta-lactate (ΔLac). The study outcome was 30-day in-hospital death. Cox proportional regression model was used to assess independent predictors of the study outcome.

RESULTS

At admission, 14.6% of patients had lactate levels ⩾2 mmol/l. In-hospital death at 30 days occurred in 57 out of 206 patients; 22.3% and 56.7% with normal or ⩾ 2 mmol/l lactate at admission, respectively. The median lactate level was 1.0 [interquartile range (IQR) 0.8-1.3] mmol/l and 1.3 (IQR 1.0-2.1) mmol/l in survivors and nonsurvivors, respectively (p-value < 0.001). After adjusting for age, relevant comorbidities, acidemia, and the severity of respiratory failure, lactate ⩾2.0 mmol/l was associated with in-hospital death (HR 2.53, 95% CI 1.29-4.95, p-value 0.0066), while Δ Lac ⩾0 was not (HR 1.37, 95% CI 0.42-4.49). These results were confirmed in patients with a pO2/FiO2-ratio (P/F ratio) ⩽300 mmHg.

CONCLUSIONS

In our study, increased arterial lactate at admission was independently associated with in-hospital death at 30 days in non-ICU patients with acute respiratory failure related to COVID-19.

Preoperative albumin corrected anion gap is associated with in-hospital and long-term mortality in patients undergoing coronary artery bypass grafting in a retrospective cohort study

Background

Coronary artery disease remains a global health concern and the leading cause of death. Till today, coronary artery bypass grafting (CABG) is one of the main treatment strategies for coronary artery disease, especially for Multivessel coronary disease or complex coronary lesions. The present study aimed to explore the relationship of preoperative albumin corrected anion gap (ACAG) with mortality in all those patients who undergoing CABG.

Methods

All the patients undergoing CABG were included in the study. All clinical data were collected from CareVue and MetaVision system. The predictive value of ACAG for mortality was determined by receiver operating characteristic (ROC) curves survival curves were estimated using the Kaplan-Meier method. Multivariate regression models were constructed to determine the association of ACAG with mortality.

Results

A total of 2,180 patients were identified and divided into a high ACAG group (ACAG ≥16.0 mmol/L) and low ACAG group (ACAG <16.0 mmol/L) according to the ROC analysis. Patients in the high ACAG group were older and presented with more comorbidities and concomitant valvular surgeries. Further more, in the high ACAG group, we observed a higher length of stay in the intensive care unit [3.88 (2.15, 7.09) vs. 2.29 (1.29, 3.94), P<0.001]. Both the in-hospital mortality [28 (4.5%) vs. 11 (0.7%), P<0.001], and the 4-year mortality [125 (27.1%) vs. 111 (12.7%), P<0.001] were also rised in those patients. And it was also showed in the survival curves, patients with ACAG ≥16.0 mmol/L had a significant lower 4-year survival (P<0.001). While in the multivariate regression model, we found ACAG was act as an independent risk factor for both the in-hospital mortality [odds ratio (OR): 1.248 (1.060, 1.470), P=0.008] and the 4-year mortality [hazard ratio (HR): 1.134 (1.063, 1.210), P<0.001]. An ACAG ≥16.0 mmol/L was significantly associated with a 2.7-fold risk of in-hospital mortality [OR: 2.732 (1.129, 6.610), P=0.026].

Conclusions

Preoperative ACAG is an independent risk factor for in-hospital and long-term mortality in CABG patients. A higher ACAG may relate to severe coronary artery stenosis and cardiac dysfunction, which is more likely to lead to a postoperative systemic inflammatory response, microcirculation disorder, and subsequent complications.

A simple APACHE IV risk dynamic nomogram that incorporates early admitted lactate for the initial assessment of 28-day mortality in critically ill patients with acute myocardial infarction

BACKGROUND

Early risk stratification is important for patients with acute myocardial infarction (AMI). We aimed to develop a simple APACHE IV dynamic nomogram, combined with easily available clinical parameters within 24 h of admission, thus improving its predictive power to assess the risk of mortality at 28 days.

METHODS

Clinical information on AMI patients was extracted from the eICU database v2.0. A preliminary XGBoost examination of the degree of association between all variables in the database and 28-day mortality was conducted. Univariate and multivariate logistic regression analysis were used to perform screening of variables. Based on the multifactorial analysis, a dynamic nomogram predicting 28-day mortality in these patients was developed. To cope with missing data in records with missing variables, we applied the multiple imputation method. Predictive models are evaluated in three main areas, namely discrimination, calibration, and clinical validity. The discrimination is mainly represented by the area under the receiver operating characteristic curve (AUC), net reclassification improvement (NRI) and integrated discrimination improvement (IDI). Calibration is represented by the calibration plot. Clinical validity is represented by the decision curve analysis (DCA) curve.

RESULTS

A total of 504 people were included in the study. All 504 people were used to build the predictive model, and the internal validation model used a 500-bootstrap method. Multivariate analysis showed that four variables, APACHE IV, the first sample of admission lactate, prior atrial fibrillation (AF), and gender, were included in the nomogram as independent predictors of 28-day mortality in AMI. The prediction model had an AUC of 0.819 (95%CI 0.770-0.868) whereas the internal validation model had an AUC of 0.814 (95%CI 0.765-0.860). Calibration and DCA curves indicated that the dynamic nomogram in this study were reflective of real-world conditions and could be applied clinically. The predictive model composed of these four variables outperformed a single APACHE IV in terms of NRI and IDI. The NRI was 16.4% (95% CI: 6.1-26.8%; p = 0.0019) and the IDI was 16.4% (95% CI: 6.0-26.8%; p = 0.0020). Lactate accounted for nearly half of the total NRI, which showed that lactate was the most important of the other three variables.

CONCLUSION

The prediction model constructed by APACHE IV in combination with the first sample of admission lactate, prior AF, and gender outperformed the APACHE IV scoring system alone in predicting 28-day mortality in AMI. The prediction dynamic nomogram model was published via a website app, allowing clinicians to improve the predictive efficacy of the APACHE IV score by 16.4% in less than 1 min.

Construction of a lactate-related prognostic signature for predicting prognosis after surgical repair for acute type a aortic dissection

Background: Serum lactate is commonly measured in the perioperative period in patients who have undergone surgery for an acute type A aortic dissection (ATAAD). However, conflicting data has been reported as to whether lactate elevation is associated with short-term prognosis. The aim of the current study was to determine the association between perioperative arterial lactate levels and postoperative 30-day mortality. Methods: Patients who underwent repair of a ATAAD at our institution were retrospectively screened and those with comprehensive measurements of serum lactate before surgery and at 0, 1, 3, 6, 12, and 24 h after surgery in the intensive care unit (ICU) were selected for the analysis. Patients' demographic features and outcomes were reviewed to determine risk factors associated with 30-day mortality using logistic regression modeling. The association between serum lactate levels at different time points and 30-day mortality were analyzed by receiver-operating characteristic curves. Results: 513 patients were identified and retrospectively analyzed for this study including 66 patients (12.9%) who died within 30 days after surgery. Patients who died within 30 days after surgery had elevated lactate levels measured before surgery and at 0, 1, 3, 6, 12, and 24 h after their ICU stay. Lactate measured at 24 h post ICU admission (odds ratio, 2.131; 95% confidence interval, 1.346-3.374; p = 0.001) was a predictor of 30-day mortality. The area under the curve (AUC) for 30-day mortality with lactate levels at 12 h and 24 h post ICU stay were 0.820 and 0.805, respectively. Conclusion: Early elevation of lactate level is correlated with increased 30-day mortality in patients who received ATAAD surgical repair.

Admission lactate level and the GRACE 2.0 score are independent and additive predictors of 30-day mortality of STEMI patients treated with primary PCI-Results of a real-world registry

BACKGROUND

In many of the risk estimation algorithms for patients with ST-elevation myocardial infarction (STEMI), heart rate and systolic blood pressure are key predictors. Yet, these parameters may also be altered by the applied medical treatment / circulatory support without concomitant improvement in microcirculation. Therefore, we aimed to investigate whether venous lactate level, a well-known marker of microcirculatory failure, may have an added prognostic value on top of the conventional variables of the "Global Registry of Acute Coronary Events" (GRACE) 2.0 model for predicting 30-day all-cause mortality of STEMI patients treated with primary percutaneous coronary intervention (PCI).

METHODS

In a prospective single-center registry study conducted from May 2020 through April 2021, we analyzed data of 323 cases. Venous blood gas analysis was performed in all patients at admission. Nested logistic regression models were built using the GRACE 2.0 score alone (base model) and with the addition of venous lactate level (expanded model) with 30-day all-cause mortality as primary outcome measure. Difference in model performance was analyzed by the likelihood ratio (LR) test and the integrated discrimination improvement (IDI). Independence of the predictors was evaluated by the variance inflation factor (VIF). Discrimination and calibration was characterized by the c-statistic and calibration intercept / slope, respectively.

RESULTS

Addition of lactate level to the GRACE 2.0 score improved the predictions of 30-day mortality significantly as assessed by both LR test (LR Chi-square = 8.7967, p = 0.0030) and IDI (IDI = 0.0685, p = 0.0402), suggesting that the expanded model may have better predictive ability than the GRACE 2.0 score. Furthermore, the VIF was 1.1203, indicating that the measured lactate values were independent of the calculated GRACE 2.0 scores.

CONCLUSIONS

Our results suggest that admission venous lactate level and the GRACE 2.0 score may be independent and additive predictors of 30-day all-cause mortality of STEMI patients treated with primary PCI.

The Relationship between Training Cycle-Dependent Fluctuations in Resting Blood Lactate Levels and Exercise Performance in College-Aged Rugby Players

An increase in resting blood lactate (La^-) concentration due to metabolic conditions has been reported. However, it is not clear whether resting La^- changes with training cycles in athletes. The purpose of this study was to test the hypotheses that (1) the morning resting La^- levels are lower in periods of high training compared to periods of low training and (2) these changes in La^- concentration are related to athletes' metabolic capacity during exercise in male college-aged rugby players. Resting La^- and blood glucose concentrations were measured in the morning in eight league rugby players during the summer pre-season period (Pre-period), the training and competition season period (TC-period), and the winter post-season period (Post-period). In each period, anaerobic power, La^- concentration, and respiratory responses were measured during the 40 s maximal Wingate anaerobic test (WT). The resting La^- concentration in the morning was significantly lower in the TC-Period (1.9 ± 0.6 mmol/L) than in the Post-Period (2.3 ± 0.9 mmol/L). The rate of decrease in La^- level immediately after the 40 s WT was significantly higher in the TC-Period than in the Post-Period. The resting La^- concentration was significantly correlated with the peak oxygen uptake and the carbon dioxide output during the WT. These results support the hypothesis that an athlete's training cycle (i.e., in season and off season) influences the resting La^- levels as well as the metabolic capacity during high-intensity exercise. The monitoring of resting La^- fluctuations may provide a convenient indication of the training cycle-dependent metabolic capacity in athletes.

The value of anion gap for predicting the short-term all-cause mortality of critically ill patients with cardiac diseases, based on MIMIC-III database

BACKGROUND

The association of anion gap (AG) with short-term mortality in the critically ill patients with cardiac diseases is still not well understood.

OBJECTIVE

To evaluate the association of AG with short-term mortality, and the predictive ability of AG for short-term mortality in critically ill patients with cardiac diseases.

METHODS

This retrospective cohort study enrolled 9104 critically ill patients with cardiac diseases from the Medical Information Mart for Intensive Care III (MIMIC III) database. The restricted cubic spline models were used to evaluate the nonlinear relationship between AG and short-term mortality. Cox proportional hazards regression models and subgroup analysis were applied to assess the association of AG with short-term mortality.

RESULTS

The data were divided into three groups by AG tertiles: tertile I (AG <12, n = 2095), tertile II (12 ≤ AG < 15, n = 3195), and tertile III (15 ≤ AG, n = 3814). The restricted cubic spline models revealed continuous AG was non-linearly related to short-term mortality. The elevated AG tertiles were strongly associated with higher in-hospital, 30-day and 90-day mortality (all P for trend < 0.001). After adding AG to traditional severity scores, the area under curves (AUCs) elevated significantly compared to severity scores alone (all DeLong's test: P < 0.001). Subgroup analysis did not indicate significant interaction in most diverse subgroups.

CONCLUSION

AG was an independent risk factor for short-term all-cause mortality in critically ill patients with cardiac diseases. AG improved significantly the mortality predictive abilities of traditional severity scores when AG was added to these scores.

Early dynamic behavior of lactate in predicting continuous renal replacement therapy after surgery for acute type A aortic dissection

Background

It has been well known that hyperlactatemia is an independent risk factor for postoperative mortality in patients who received acute type A aortic dissection (ATAAD) surgery. Some patients may require the assistance of continuous renal replacement therapy (CRRT) for acute postoperative renal deficiency and often associate with increased mortality rate. This study aimed to examine the association between the early dynamic change of lactate levels and postoperative CRRT in ATAAD patients who received surgical repairment.

Methods

This retrospective study included 503 patients who received ATAAD surgeries. Serum lactate levels were measured before operation and at 0, 1, 3, 6, 12, 24 h post intensive care unit (ICU) admission. We examined the association between dynamic changes of lactate and CRRT.

Results

Among all patients, 19.9% (100 patients) required CRRT. Our data showed that the lactate levels were higher in the CRRT group at all timepoints compared to the non-CRRT group. In a multivariate model, lactate levels at 12 h post ICU admission [odds ratio (OR), 1.362; p = 0.007] was identified as an independent predictor for requiring CRRT. Unsurprisingly, 30-day mortality in the CRRT group (41%) was 8.2 times higher than in the non-CRRT group (5%). To better understand the associations between CRRT and lactate levels, patients in the CRRT group were further stratified into the non-survivor group (n = 41) and survivor group (n = 59) based on the 30-day mortality. Elevated lactate levels measured upon ICU admission (OR, 1.284; p = 0.001) and decreased 24 h lactate clearance (OR, 0.237; p = 0.039) were independent risk factors for 30-day mortality in patients who received CRRT. The area under the curve to predict requirement for CRRT at 6 and 12 h post CICU admission were 0.714 and 0.722, respectively, corresponding to lactate cut-off levels of 4.15 and 2.45 mmol/L.

Conclusion

The CRRT is commonly required in patients who received ATAAD surgery and often associated with worse mortality. Early dynamic changes of lactate levels can be used to predict the requirement of postoperative CRRT.

Cardiovascular Dysfunction in COVID-19: Association Between Endothelial Cell Injury and Lactate

Coronavirus disease 2019 (COVID-19), an infectious respiratory disease propagated by a new virus known as Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), has resulted in global healthcare crises. Emerging evidence from patients with COVID-19 suggests that endothelial cell damage plays a central role in COVID-19 pathogenesis and could be a major contributor to the severity and mortality of COVID-19. Like other infectious diseases, the pathogenesis of COVID-19 is closely associated with metabolic processes. Lactate, a potential biomarker in COVID-19, has recently been shown to mediate endothelial barrier dysfunction. In this review, we provide an overview of cardiovascular injuries and metabolic alterations caused by SARS-CoV-2 infection. We also propose that lactate plays a potential role in COVID-19-driven endothelial cell injury.

Association Between Anion Gap and Mortality in Critically Ill Patients with Cardiogenic Shock

Background

No epidemiological study has determined the association between the anion gap (AG) and all-cause mortality in critically ill patients with cardiogenic shock (CS). This study was conducted to clarify the relationship between the AG and mortality in CS.

Methods

We extracted clinical data from the public database, MIMIC-III V1.4, by using a generalized additive model to identify the nonlinear relationship between the AG and the 30-day mortality in 1248 intensive care unit patients. Cox proportional hazard models were used to assess the association between the AG and the 30-day, 90-day, and 365-day mortality in CS.

Results

The AG and 30-day all-cause mortality showed a nonlinear relationship, indicated by a J-shaped curve. In the multivariate analysis, after adjusting for potential confounders, a high AG was associated with an increased risk of 30-day, 90-day, and 365-day all-cause mortality in patients with CS compared with patients who had low AG (hazard ratio [95% confidence interval] 1.62 [1.14-2.30]; 1.35 [1.04-1.84]; and 1.38 [1.03-1.84], respectively). Similar results were shown in Model I (adjusted for age, sex and ethnicity) and in Model II (fully adjusting for age, ethnicity, sex, acute kidney injury stage, CHF, renal disease, stroke, malignancy, respiratory failure, pneumonia, sodium, potassium, chloride, BUN, PT, WBC, pH, creatinine, albumin, glucose, bicarbonate, vasopressor use, diastolic blood pressure, respiration rate, temperature, the Elixhauser Comorbidity Index, SOFA score and SAPSII score).

Conclusion

The relationship between the AG and 30-day all-cause mortality followed a J-shaped curve. Higher AG was associated with an increased risk of 30-day, 90-day, and 365-day all-cause mortality in critically ill patients with CS.

Arterial Lactate in Cardiogenic Shock: Prognostic Value of Clearance Versus Single Values

OBJECTIVES

This study sought to compare single lactate values at admission (L1) and after 8 h (L2) with lactate clearance (LC) for mortality prediction in cardiogenic shock (CS).

BACKGROUND

Early estimation of prognosis in CS complicating acute myocardial infarction is crucial for tailored treatment selection. Arterial lactate is the most widely used point-of-care parameter in CS. In septic shock, lactate reduction over time-LC-has been extensively investigated. However, in CS, only limited data exist, and the prognostic value of LC is unknown.

METHODS

This study is a subanalysis of the IABP-SHOCK II (Intraaortic Balloon Pump in Cardiogenic Shock II) trial and the corresponding registry. Lactate levels were prospectively collected. All-cause mortality at 30 days was assessed as primary endpoint.

RESULTS

For 671 of 783 (85.7%) patients, L1 and L2 values were available. The area under the receiver-operating characteristic curve (L1: 0.69; L2: 0.76; LC: 0.59) showed no difference between L1 and LC (p = 0.20). In contrast, L2 was a significantly better predictive parameter than L1 or LC (p < 0.001 for both). In multivariable stepwise Cox regression analysis, L2 ≥3.1 mmol/l (best cutoff value by Youden index) and LC <-3.45%/h remained independently predictive for time to death (p < 0.001 for both), with L2 showing the highest chi-square test score (42.1) and hazard ratio (2.89; 95% confidence interval: 2.10 to 3.97).

CONCLUSIONS

Arterial lactate after 8 h is superior in mortality prediction in comparison with baseline lactate and LC. A cutoff value of 3.1 mmol/l for lactate after 8 h showed the best discrimination for assessing early prognosis in CS and may serve as new treatment goal. (Intraaortic Balloon Pump in Cardiogenic Shock II [IABP-SHOCK II]; NCT00491036).

A Targeted Metabolomics-Based Assay Using Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes Identifies Structural and Functional Cardiotoxicity Potential

Implementing screening assays that identify functional and structural cardiotoxicity earlier in the drug development pipeline has the potential to improve safety and decrease the cost and time required to bring new drugs to market. In this study, a metabolic biomarker-based assay was developed that predicts the cardiotoxicity potential of a drug based on changes in the metabolism and viability of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). Assay development and testing was conducted in 2 phases: (1) biomarker identification and (2) targeted assay development. In the first phase, metabolomic data from hiPSC-CM spent media following exposure to 66 drugs were used to identify biomarkers that identified both functional and structural cardiotoxicants. Four metabolites that represent different metabolic pathways (arachidonic acid, lactic acid, 2'-deoxycytidine, and thymidine) were identified as indicators of cardiotoxicity. In phase 2, a targeted, exposure-based biomarker assay was developed that measured these metabolites and hiPSC-CM viability across an 8-point concentration curve. Metabolite-specific predictive thresholds for identifying the cardiotoxicity potential of a drug were established and optimized for balanced accuracy or sensitivity. When predictive thresholds were optimized for balanced accuracy, the assay predicted the cardiotoxicity potential of 81 drugs with 86% balanced accuracy, 83% sensitivity, and 90% specificity. Alternatively, optimizing the thresholds for sensitivity yields a balanced accuracy of 85%, 90% sensitivity, and 79% specificity. This new hiPSC-CM-based assay provides a paradigm that can identify structural and functional cardiotoxic drugs that could be used in conjunction with other endpoints to provide a more comprehensive evaluation of a drug's cardiotoxicity potential.

A prognostic nomogram for long-term major adverse cardiovascular events in patients with acute coronary syndrome after percutaneous coronary intervention

BACKGROUND

Accurate prediction of major adverse cardiovascular events (MACEs) is very important for the management of acute coronary syndrome (ACS) patients. We aimed to construct an effective prognostic nomogram for individualized risk estimates of MACEs for patients with ACS after percutaneous coronary intervention (PCI).

METHODS

This was a prospective study of patients with ACS after PCI from January 2013 to July 2019 (n = 2465). After removing patients with incomplete clinical information, a total of 1986 patients were randomly divided into evaluation (n = 1324) and validation (n = 662) groups. Predictors included in the nomogram were determined by a multivariate Cox proportional hazards regression model based on the training set. Receiver operating characteristic (ROC) curves and calibration curves were used to assess the discrimination and predictive accuracy of the nomogram, which were then compared with those of the classic models. The clinical utility of the nomogram was assessed by X-tile analysis and Kaplan-Meier curve analysis.

RESULTS

Independent prognostic factors, including lactate level, age, left anterior descending branch stenosis, right coronary artery stenosis, brain natriuretic peptide level, and left ventricular ejection fraction, were determined and contained in the nomogram. The nomogram achieved good areas under the ROC curve of 0.712-0.762 in the training set and 0.724-0.818 in the validation set and well-fitted calibration curves. In addition, participants could be divided into two risk groups (low and high) according to this model.

CONCLUSIONS

A simple-to-use nomogram incorporating lactate level effectively predicted 6-month, 1-year, and 4-year MACE incidence among patients with ACS after PCI.

Ockham's razor and the metabolic syndrome

The broad effects of bariatric/metabolic surgery on virtually every tissue and organ system remain unexplained. Weight loss, although a major factor, does not fully account for the rapid, full, and durable remission of type 2 diabetes, return of islet function, reduction of the prevalence of cancers, increase in gray matter of the brain, and decrease in all-cause mortality. This review supports the thesis that the metabolic syndrome is not a group of separate diseases but rather multiple expressions of a shared defect in the utilization of carbohydrates and lipids. That error is probably caused by a dysmetabolic signal from the foregut, stimulated by food, that limits entry of 2-carbon fragments into the tricarboxylic acid cycle, the accumulation of lactate and, in turn, increases in glucose and insulin. Surgery limits that signal by reducing contact between food and foregut mucosa. Speciation of that signal(s) may offer a new pathway for drug development.

Quality of life following adult veno-venous extracorporeal membrane oxygenation for acute respiratory distress syndrome: a systematic review

BACKGROUND

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) has been used successfully for the past decade in adult patients with acute respiratory distress syndrome (ARDS) refractory to conventional ventilatory support. However, knowledge of the health-related quality of life (HRQoL) in VV-ECMO patients is still limited. Thus, this study aimed to provide a comprehensive overview of the HRQoL following VV-ECMO support in ARDS patients.

METHODS

A systematic search was performed on PubMed and Web of Science databases from January 1st, 2009 to October 19th, 2020. Studies reporting on HRQoL following VV-ECMO for ARDS in adults were included. Two authors independently selected studies, extracted data, and assessed methodological quality.

RESULTS

Eight studies were eligible for inclusion, consisting of seven observational studies and one randomized controlled trial (total N = 441). All eight studies had a quantitative design and reported 265 VV-ECMO survivors to have a reduced HRQoL compared to a generally healthy population. Follow-up time varied between six months to three years. Additionally, only four studies (total N = 335) compared the HRQoL of VV-ECMO (N = 159) to conventionally treated survivors (N = 176), with one study showing a significantly better HRQoL in VV-ECMO survivors, while three studies were stating comparable HRQoL across groups. Notably, most survivors in these studies appeared to experience varying degrees of anxiety, depression, and post-traumatic stress disorder (PTSD).

CONCLUSIONS

ARDS survivors supported by VV-ECMO have a decline in HRQoL and suffered from physical and psychological impairments. This HRQoL reduction is comparable or even better to the HRQoL in conventionally treated ARDS survivors.

Inhibiting the Pkm2/b-catenin axis drives in vivo replication of adult cardiomyocytes following experimental MI

Adult mammalian cardiomyocytes (CM) are postmitotic, differentiated cells that cannot re-enter the cell cycle after any appreciable injury. Therefore, understanding the factors required to induce CM proliferation for repair is of great clinical importance. While expression of muscle pyruvate kinase 2 (Pkm2), a cytosolic enzyme catalyzing the final step in glycolysis, is high in end-stage heart failure (HF), the loss of Pkm2 promotes proliferation in some cellular systems, in vivo. We hypothesized that in the adult heart CM proliferation may require low Pkm2 activity. Thus, we investigated the potential for Pkm2 to regulate CM proliferation in a mouse model of myocardial infarction (MI) employing inducible, cardiac-specific Pkm2 gene knockout (Pkm2KOi) mice. We found a lack of cardiac hypertrophy or expression of the fetal gene program in Pkm2KOi mice post MI, as compared to vehicle control animals (P < 0.01), correlating with smaller infarct size, improved mitochondrial (mt) function, enhanced angiogenesis, reduced degree of CM apoptosis, and reduced oxidative stress post MI. There was significantly higher numbers of dividing CM in the infarct zone between 3-9 days post MI (P < 0.001). Mechanistically, we determined that Pkm2 interacts with β-catenin (Ctnnb1) in the cytoplasm of CM, inhibiting Ctnnb1 phosphorylation at serine 552 and tyrosine 333, by Akt. In the absence of Pkm2, Ctnnb1 translocates to the nucleus leading to transcriptional activation of proliferation-associated target genes. All these effects are abrogated by genetic co-deletion of Pkm2 and Ctnnb1. Collectively, this work supports a novel antiproliferative function for Pkm2 in CM through the sequestration of Ctnnb1 in the cytoplasm of CM whereas loss of Pkm2 is essential for CM proliferation. Reducing cardiac Pkm2 expression may provide a useful strategy for cardiac repair after MI in patients.

Assessing lactate concentration as a predictor of 28-day in-hospital mortality in the presence of ethanol: A retrospective study of emergency department patients

BACKGROUND

Presence of ethanol (EtOH) may alter the relationship between blood lactate concentrations and mortality. This study compares lactate-associated mortality risk in the presence and absence of EtOH.

METHODS

We performed a retrospective cohort study including all patients, age >17 years, presenting from January 2012-December 2018, to an urban, academic emergency department, with a clinically measured lactate. Data were electronically abstracted from the medical record. The primary outcome was 28-day in-hospital mortality. Patients were grouped by EtOH test results as follows: 1) present (any EtOH detected), 2) absent (EtOH concentration measured and not detected), or 3) not ordered. Marginal analysis was used to calculated probability of mortality for fixed values of lactate and model covariates.

RESULTS

Of 40,956 adult emergency department patients with measured lactate, we excluded 768 (1.89%) for lactate >10.0 mmol/L, leaving 40,240 for analysis: 4,066 (10.1%) EtOH present, 10,819 (26.9%) EtOH absent, 25,355 (63%) EtOH not ordered. Of these, 1790 (4.4%) had 28-day in-hospital mortality. Marginal probability of mortality calculated for specific lactate values found less risk for EtOH Present patients versus EtOH absent patients at lactate 0.0 mmol/L (0.8% [95%CI: 0.5-1.2%] vs 3.2% [2.8-3.6%]), 2.0 mmol/L (1.5% [1.1-1.9%] vs 4.0% [3.7-4.3%]), 4.0 mmol/L (2.6% [2.2-3.1%] vs 5.0% [4.6-5.4%]), until 6.0 mmol/L (4.5% [3.7-5.4%] vs 6.2% [5.4-7.0%]).

CONCLUSION

EtOH presence significantly alters lactate-associated mortality risk when lactate <6.0 mmol/L. Emergency department clinicians should interpret these lactate values with caution and consider other data for risk stratification when EtOH is present.

Unusual aetiology of a type 2 myocardial infarction: a case-based review

Organophosphate pesticide (OP) poisoning is quite common and can cause cardiovascular complications and even direct myocardial injury. However, no guideline has included an acute poisoning as a potential cause for a type 2 myocardial infarction (MI) so far. Here we present a case of a 61-year-old woman brought by ambulance to emergency department one hour after accidental ingestion of an unknown quantity of a solution she used against flea infestation. The patient presented with dizziness, myosis, excessive sweating, hypersalivation, sphincteric incontinence, muscle fasciculation, tremor of the extremities, pale skin, alcoholic and pesticide breath odour. Even though we had no guidelines to fall back on, we successfully treated the patient with low-molecular-weight heparin, antiplatelets, statin, diltiazem, antidote therapy, and supportive care. Physicians should be aware that OP poisoning can induce type 2 MI as a complication within a few hours since exposure, and emergency management should always include close cardiac monitoring.

Serum Lactate and A Relative Change in Lactate as Predictors of Mortality in Patients With Cardiogenic Shock - Results from the Cardshock Study

INTRODUCTION

Cardiogenic shock complicating acute myocardial infarction has a very high mortality. Our present study focuses on serial measurement of lactate during admission due to cardiogenic shock and the prognostic effect of lactate and a relative change in lactate in patients after admission and the institution of intensive care treatment.

METHODS AND RESULTS

This is a secondary analysis of the CardShock study. Data on lactate at baseline were available on 217 of 219 patients.In the study population, the median baseline lactate was 2.8 mmol/L (min-max range, 0.5-23.1 mmol/L).At admission, lactate was predictive of 30-day mortality with an adjusted Hazard ratio (HR) of 1.20 mmol/L (95% confidence interval, CI 1.14-1.27). Within the first 24 h of admission, baseline lactate remained predictive of 30-day mortality. Lactate at 6 h had a HR of 1.14 (95% CI 1.06-1.24) and corresponding values at 12 and 24 h had a HR of 1.10 (1.04-1.17), and of HR 1.19 (95% CI 1.07-1.32), respectively. A 50% reduction in lactate within 6 h resulted in a HR of 0.82 (95% CI 0.72-0.94). Corresponding hazard ratios at 12 and 24 h, were 0.87 (95% CI 0.76-0.98) and 0.74 (95% CI 0.60-0.91), respectively.

CONCLUSION

The main findings of the present study are that baseline lactate is a powerful predictor of 30-day mortality, lactate at 6, 12, and 24 h after admission are predictors of 30-day mortality, and a relative change in lactate is a significant predictor of survival within the first 24 h after instituting intensive care treatment adding information beyond the information from baseline values.