Daytime variation of perioperative myocardial injury in cardiac surgery and its prevention by Rev-Erbα antagonism: a single-centre propensity-matched cohort study and a randomised study

The integration of scRNA-seq with microarray and in-vivo experiments facilitates a comprehensive elucidation of the molecular mechanisms underlying endothelial cell involvement in myocardial infarction

Myocardial infarction (MI) remains a major global health challenge, with endothelial cell function playing a crucial role in its progression. Advances in single-cell RNA sequencing (scRNA-seq) have enhanced our understanding of MI pathogenesis. This study aims to identify key genes within endothelial cells using scRNA-seq data and validate them through microarray data and in vivo models elucidate their role in the progression of MI. ScRNA-seq and microarray datasets relevant to MI were obtained from the GEO database. The Seurat package was used for data pre-processing and marker gene identification. Endothelial cell subpopulations were characterised using the hdWGCNA package, while intercellular interactions with fibroblasts were assessed using CellChat. Key genes were identified using comprehensive bioinformatics techniques such as scCODE, FindMarkers and protein-protein interaction (PPI) analysis, with validation from microarray data and in vivo experiments (WB, qPCR, immunofluorescence) in the model of MI. The analysis via scRNA-seq revealed 16 distinct cell clusters encompassing 7 unique cell types. Endothelial cells were categorized into 8 subpopulations by hdWGCNA; notably, Endothelial Cells-2 exhibited significant interactions with fibroblasts mediated by PDGF, PROS, and GAS signaling pathways. Integration of hdWGCNA, scCODE and FindMarkers, 10 key genes were identified, which were subsequently refined to DBP, NR1D1, and TEF following PPI analysis. These genes demonstrated marked downregulation the progression of MI, as confirmed by subsequent in vivo experiments. This study highlights the crucial roles of DBP, NR1D1, and TEF in MI development, providing a basis for future research on endothelial cell function in cardiovascular disease.

RPS27A as a potential clock-related diagnostic biomarker for myocardial infarction: Comprehensive bioinformatics analysis and experimental validation

BACKGROUND

The circadian system plays a crucial role in managing cardiovascular functions, with disturbances in this system associated with Myocardial Infarction (MI). Despite this connection, the exact mechanisms by which clock genes influence MI occurrence are not well-defined. This research focused on investigating the link between clock genes and MI.

METHODS

The authors examined MI microarray datasets (GSE151412 and GSE60993) from the GEO database, concentrating on Differentially Expressed Genes (DEGs) associated with the circadian system. To clarify critical biological functions and pathways, the authors performed enrichment analyses using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG). Through Lasso regression, the authors pinpointed hub genes and confirmed their relevance using both the GSE66360 dataset and quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). Furthermore, the authors conducted single-Gene Set Enrichment Analysis (GSEA) to reveal pathways linked to the hub gene. The analysis extended to exploring drug interactions and networks involving competing endogenous RNA (ceRNA).

RESULTS

The present analysis identified ten clock genes associated with circadian rhythms that showed differential expression between MI patients and healthy controls. Enrichment analysis suggested these genes' roles in pathways like the Gap junction and circadian rhythm pathways. Following Lasso regression and validation, RPS27A was identified as the main hub gene. GSEA further highlighted enriched pathways, such as mismatch repair. Additionally, immune infiltration analysis revealed notable differences in B-cell and CD4+ T-cell populations between the MI group and the control group.

CONCLUSION

The present findings suggest that the clock-related gene RPS27A is associated with MI, potentially influencing its development through circadian rhythm regulation. These results enhance the understanding of MI pathogenesis and may offer new avenues for therapeutic intervention.

Exploring the Role of Circadian Rhythm-Related Genes in the Identification of Sepsis Subtypes and the Construction of Diagnostic Models Based on RNA-seq and scRNA-seq

Sepsis is a severe systemic response to infection that may lead to the dysfunction of multiple organ systems and may even be life-threatening. Circadian rhythm-related genes (CRDRGs) regulate the circadian clock and affect many physiological processes, including immune responses. In patients with sepsis, circadian rhythms may be disrupted, thus leading to problems such as immune responses. RNA-seq datasets of sepsis and control groups were downloaded from the Gene Expression Omnibus (GEO) database, and two sepsis subtypes were identified based on differentially expressed CRDRGs. Two gene modules related to sepsis diagnosis and subtypes were obtained using the weighted co-expression network (WGCNA) algorithm. Subsequently, using four machine learning algorithms (random forest, support vector machine, a generalized linear model, and xgboost), genes related to sepsis diagnosis were identified from the intersection genes of the two modules, and a diagnostic model was constructed. Single-cell sequencing (scRNA-seq) data were obtained from the GEO database to explore the expression landscape of diagnostic-related genes in different cell types. Finally, an RT-qPCR analysis of diagnosis-related genes confirmed the differences in expression trends between the two groups. Multiple differentially expressed CRDRGs were observed in the sepsis and control groups, and two subtypes were identified based on their expression levels. There were apparent differences in the distribution of samples of the two subtypes in two-dimensional space and the pathways involved. Using multiple machine learning algorithms, the intersection genes in the two most relevant modules of the WGCNA were identified, and a robust diagnostic model was constructed with five genes (ARHGEF18, CHD3, PHC1, SFI1, and SPOCK2). The AUC of this model reached 0.987 on the validation set, showing an excellent prediction performance. In this study, two sepsis subtypes were identified, and a sepsis diagnostic model was constructed via consensus clustering and machine learning algorithms. Five genes were identified as diagnostic markers for sepsis and can thus assist in clinical diagnosis and guide personalized treatment.

Association between Induction Start Time and Labor Duration in Nulliparous Women Undergoing Elective Induction of Labor

This study aimed to examine the association between elective induction of labor (EIOL) start time and labor duration among nulliparous women.The ARRIVE trial was a multicenter randomized controlled trial of induction of labor at 390/7 to 394/7 weeks versus expectant management in low-risk nulliparous women. In this secondary analysis, we included participants randomized to the induction group who had an EIOL without spontaneous labor or rupture of membranes prior to the induction start. The start time of EIOL was categorized as: early a.m. (midnight to 5:59 a.m.), late AM (6 AM-11:59 a.m.), early p.m. (noon-5:59 p.m.), or late p.m. (6 p.m.-11:59 p.m.). The primary outcome was labor duration. Cesarean delivery rates by induction start time were also examined. Multivariable analysis was conducted controlling for age, body mass index, insurance status, and modified Bishop score on admission (<5 or ≥5).Of 3,062 women randomized to EIOL, 2,197 were included in this analysis. EIOL occurred in the early a.m. in 13%, in late a.m. in 28%, in early p.m. in 13%, and in late p.m. in 45%. Participants induced in the late a.m. had the shortest mean labor durations (21.5 ± 11.3 hours) and the highest frequency of delivery at < 24 hours (68%). In adjusted analyses, induction in the late a.m. (vs. grouped other time periods) remained significantly associated with shorter labor duration (-1.5 hours; confidence interval: -2.5 and -0.4; p = 0.006), and there was no interaction between Bishop score and time of EIOL. Cesarean delivery rates did not differ by start time.Induction of labor starting between 6 a.m. and 11:59 a.m. was associated with shorter labor durations, independent of baseline maternal characteristics including cervical status on admission. · Women were associated with shorter labor durations. · Cesarean delivery rates did not differ by EIOL start time.. · Differences in labor management by time of day may in part explain these findings..

Impact of the Circadian Rhythm and Seasonal Changes on the Outcome of Cardiovascular Interventions

The activities of living beings fluctuate according to seasonal changes and circadian rhythms. The interaction of organisms with their environment, notably weather conditions and night-day cycles, modulate homeostatic mechanisms and influence physiological responses in stressful situations. In humans, it is well established that cardiovascular events such as myocardial infarction, stroke and acute heart failure more frequently occur in winter than in summer season (non-tropical regions) and in the morning than in the evening. While the effects of cardiovascular medications vary during the day, the influence of circadian rhythms on the outcomes of invasive interventions is the subject of conflicting debates. This paper analyzes the impact of seasonal variability and circadian rhythms on physiological responses and the occurrence of complications in cardiac surgery and interventional cardiology.

Circadian immune system in solid organ transplantation: a review article

The innate and adaptive immune systems are intricately regulated by the circadian clock machinery. Recent clinical investigations have shed light on the influence of timing in organ procurement and transplantation on graft survival. In this review, we explore various mechanisms of immunological functions associated with the steps involved in organ transplantation, spanning from surgical harvesting to reperfusion and linking to the circadian rhythm. A deeper understanding of these processes has the potential to extend the principles of chrono-immunotherapy to the realm of organ transplantation, with the aim of enhancing graft durability and improving patient outcomes. This review concludes with some perspectives on future directions in this exciting and still evolving field of research.

Novel assessment of CPAP adherence data reveals distinct diurnal patterns

STUDY OBJECTIVES

Obstructive sleep apnea is a prevalent condition effectively treated by continuous positive airway pressure (CPAP) therapy. CPAP adherence data, routinely gathered in clinical practice, include detailed information regarding both duration and timing of use. The purpose of the present study was to develop a systematic way to measure the diurnal pattern of CPAP adherence data and to see if distinct patterns exist in a clinical cohort.

METHODS

Machine learning techniques were employed to analyze CPAP adherence data. A cohort of 200 unselected patients was assessed and a cluster analysis was subsequently performed. Application of this methodology to 17 patients with different visually noted patterns was carried out to further assess performance.

RESULTS

Each 30-day period of CPAP use for each patient was characterized by 4 variables describing the time of day of initiation and discontinuation of CPAP use, as well as the consistency of use during those times. Further analysis identified 6 distinct clusters, reflecting different timing and adherence patterns. Specifically, clusters with relatively normal timing vs delayed timing were identified. Finally, application of this methodology showed generally good performance with limitations in the ability to characterize shift worker and non-24 rhythms.

CONCLUSIONS

This study demonstrates a methodology for analysis of diurnal patterns from CPAP adherence data. Furthermore, distinct timing and adherence patterns are demonstrated. The potential impact of these patterns on the beneficial effects of CPAP requires elucidation.

CITATION

Scharf MT, Androulakis IP. Novel assessment of CPAP adherence data reveals distinct diurnal patterns. J Clin Sleep Med. 2025;21(3):493-502.

Implications of circadian disruption on intervertebral disc degeneration: The mediating role of sympathetic nervous system

The circadian clock orchestrates a broad spectrum of physiological processes, crucially modulating human biology across an approximate 24-hour cycle. The circadian disturbances precipitated by modern lifestyle contribute to the occurrence of low back pain (LBP), mainly ascribed to intervertebral disc degeneration (IVDD). The intervertebral disc (IVD) exhibits rhythmic physiological behaviors, with fluctuations in osmotic pressure and hydration levels that synchronized with the diurnal cycle of activity and rest. Over recent decades, advanced molecular biology techniques have shed light on the association between circadian molecules and IVD homeostasis. The complex interplay between circadian rhythm disruption and IVDD is becoming increasingly evident, with the sympathetic nervous system (SNS) emerging as a potential mediator. Synchronized with circadian rhythm through suprachiasmatic nucleus, the SNS regulates diverse physiological functions and metabolic processes, profoundly influences the structural and functional integrity of the IVD. This review synthesizes the current understanding of circadian regulation and sympathetic innervation of the IVD, highlighting advancements in the comprehension of their interactions. We elucidate the impact of circadian system on the physiological functions of IVD through the SNS, advocating for the adoption of chronotherapy as a brand-new and effective strategy to ameliorate IVDD and alleviate LBP.

Mild therapeutic hypothermic protection activates the PI3K/AKT signaling pathway to inhibit TRPM7 and suppress ferroptosis induced by myocardial ischemia‑reperfusion injury

The present study aimed to investigate the role of PI3K‑mediated ferroptosis signaling induced by mild therapeutic hypothermia (MTH), which was defined as a temperature of 34˚C, in protecting against myocardial ischemia-reperfusion (I/R) injury (MIRI). To meet this aim, H9C2 cells underwent hypoxia‑reperfusion (H/R) and/or MTH. The MTT assay was used to assess cell viability, cytotoxicity was measured using a lactate dehydrogenase cytotoxicity assay, and Annexin V‑FITC/PI flow cytometric analysis was used to analyze early and late cell apoptosis. In addition, 84 healthy adult male Sprague‑Dawley rats were randomly divided into seven groups (n=12), and underwent I/R and various treatments. Hemodynamics were monitored, and the levels of myocardial injury marker enzymes and oxidative stress markers in myocardial tissue were measured using ELISA. The expression levels of PI3K, AKT, transient receptor potential cation channel subfamily M member 7 (TRPM7), glutathione peroxidase 4 (GPX4) and acyl‑CoA synthetase long chain family member 4 (ACSL4) in animals and cells were measured using western blot analysis. These experiments revealed that MTH could effectively reduce myocardial infarct size, improve hemodynamic performance following MIRI and suppress myocardial apoptosis, thereby contributing to the recovery from H/R injury. Mechanistically, MTH was revealed to be able to activate the PI3K/AKT signaling pathway in cells, upregulating GPX4, and downregulating the expression levels of TRPM7 and ACSL4. Treatment with 2‑aminoethoxydiphenyl borate (an inhibitor of TRPM7) could further strengthen the myocardial protective effects of MTH, whereas treatment with erastin (promoter of ferroptosis) and wortmannin (inhibitor of PI3K) led to the effective elimination of the myocardial protective effects of MTH. Compared with in the I/R group, the PI3K/AKT activation level and the expression levels of GPX4 were both significantly increased, whereas the expression levels of TRPM7 and ACSL4 were significantly decreased in the I/R + MTH group. Taken together, the results of the present study indicated that MTH may activate the PI3K/AKT signaling pathway to inhibit TRPM7 and suppress ferroptosis induced by MIRI.

Daytime variation of in-hospital mortality and low cardiac output syndrome after pediatric cardiac surgery-a retrospective cohort study

OBJECTIVE

Recent studies suggest that adult cardiac surgery performed in the morning increases the risk of major adverse cardiac events, but it is unclear whether this association exists in pediatric cardiac surgery. This study aimed to determine whether the composite outcome of in-hospital mortality and low cardiac output syndrome (LCOS) differs between morning and afternoon pediatric cardiac surgeries.

METHODS

This retrospective cohort study enrolled 23,433 consecutive pediatric patients who underwent cardiac surgery between August 2014 and December 2021. Pediatric patients who had surgery start time between 8 AM and 11 AM (morning surgery) versus between 2 PM and 5 PM (afternoon surgery) were compared in the risk of the composite outcome. The Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery (STAT) score was used to indicate the surgical complexity. The adjusted odds radio (aOR) for the composite outcome was calculated using multivariate logistic regression. The restricted cubic spline (RCS) was performed to characterize the continuous relationship between the surgery start time and risk of the composite outcome.

RESULTS

Of 16,534 included pediatric patients, 1.2% died after morning surgery and 0.6% died after afternoon surgery. The composite outcome of in-hospital mortality and LCOS occurred in 14.2% (1,507 of 10,591) of morning surgeries and 8.6% (514 of 5,943) of afternoon surgeries: morning versus afternoon aOR, 1.186 (95% CI, 1.046 to 1.344; p = 0.008). The association was also determined in children aged 3 to 18 years (aOR = 1.598, p = 0.003), weighted between 6.1 to 8.7 kg (aOR = 1.453, p = 0.006), or more than 13 kg (aOR = 1.488, p = 0.019), and with STAT category 4-5 (aOR = 1.367, p = 0.014) subgroups. The RCS plot showed that the aOR of the composite outcome decreased with a delay in the start time of surgery.

CONCLUSION

Our study supports the selective afternoon scheduling of specific pediatric cardiac surgeries, but further investigation is needed in a multicenter cohort.KEY MESSAGESThis study reviewed 23,433 consecutive pediatric patients who underwent cardiac surgery between August 2014 and December 2021.This study suggested that afternoon surgery was associated with a lower risk of the composite outcomes of in-hospital mortality and low cardiac output syndrome.The above association was also determined in children aged 3 to 18 years, weighted between 6.1 and 8.7 kg, or more than 13 kg, and with STAT category 4-5 subgroups.The restricted cubic spline plot showed that the adjusted risk of the composite outcome decreased with a delay in the start time of surgery.Our findings support selective afternoon scheduling for specific pediatric cardiac surgery.

Circadian de(regulation) in physiology: implications for disease and treatment

Time plays a crucial role in the regulation of physiological processes. Without a temporal control system, animals would be unprepared for cyclic environmental changes, negatively impacting their survival. Experimental studies have demonstrated the essential role of the circadian system in the temporal coordination of physiological processes. Translating these findings to humans has been challenging. Increasing evidence suggests that modern lifestyle factors such as diet, sedentarism, light exposure, and social jet lag can stress the human circadian system, contributing to misalignment; i.e., loss of phase coherence across tissues. An increasing body of evidence supports the negative impact of circadian disruption on several human health parameters. This review aims to provide a comprehensive overview of how circadian disruption influences various physiological processes, its long-term health consequences, and its association with various diseases. To illustrate the relevant consequences of circadian disruption, we focused on describing the many physiological consequences faced by shift workers, a population known to experience high levels of circadian disruption. We also discuss the emerging field of circadian medicine, its founding principles, and its potential impact on human health.

Circadian rhythm and daytime variation do not affect intraoperative bacterial sternal contamination and postoperative wound infections following cardiac surgery

Studies have documented various effects of circadian rhythm and daytime variations on the cardiovascular and immune system as well as wound healing. From June to December 2016, n = 367 cardiac surgery patients were enrolled. Microbiological swabs from the mediastinum and subcutaneous wound were taken before sternal closure. Patients were assigned to groups based on operation start: morning (n = 219) or afternoon (n = 135). Bacterial contamination and wound infections were studied in relation to circadian rhythm and daytime variation. We did not observe any difference in mortality (morning: 3.7%, afternoon: 3.0%, p > 0.99) and major adverse events (morning: 8.2%, afternoon: 5.9%, p = 0.53). In 27.7% of the morning group, at least one positive intraoperative swab was observed, similar to the afternoon group (25.6%, p = 0.71). The incidence of positive presternal swabs was 15.6% in the morning compared to 9.1% in the afternoon (p = 0.18). About 90% of the germs detected were part of the natural skin flora (e.g., Cutibacterium acnes and Staphylococcus epidermidis). The incidence of sternal wound infections was 7.3% (morning) and 3.0% (afternoon) (p = 0.18). We did not find differences in the incidence of intraoperative bacterial sternal contamination, nor postoperative infections, between patients who underwent cardiac surgery in the morning or afternoon.

Integration of circadian rhythms and immunotherapy for enhanced precision in brain cancer treatment

Circadian rhythms significantly impact (patho)physiological processes, with disruptions linked to neurodegenerative diseases and heightened cancer vulnerability. While immunotherapy has shown promise in treating various cancers, its efficacy in brain malignancies remains limited. This review explores the nexus of circadian rhythms and immunotherapy in brain cancer treatment, emphasising precision through alignment with the body's internal clock. We evaluate circadian regulation of immune responses, including cell localisation and functional phenotype, and discuss how circadian dysregulation affects anti-cancer immunity. Additionally, we analyse and assess the effectiveness of current immunotherapeutic approaches for brain cancer including immune checkpoint blockades, adoptive cellular therapies, and other novel strategies. Future directions, such as chronotherapy and personalised treatment schedules, are proposed to optimise immunotherapy precision against brain cancers. Overall, this review provides an understanding of the often-overlooked role of circadian rhythms in brain cancer and suggests avenues for improving immunotherapeutic outcomes.

CYP3A4 gene expression discloses individual differences in postoperative pain susceptibility and drug treatment response in patients with lung cancer

This study investigates the influence of CYP3A4 gene polymorphisms on postoperative pain sensitivity and analgesic response in lung cancer patients undergoing intercostal nerve block with local anesthetics. Sixty patients (ages 31-74) undergoing thoracoscopic lung cancer surgery were enrolled and divided into two groups based on CYP3A4 gene expression level: Group I (high CYP3A4) and Group II (low CYP3A4). Postoperative pain was assessed using the Visual Analogue Scale (VAS), and patient-controlled intravenous analgesia (PCIA) pump usage, ECG ST-T segment changes, complications, hospital stay, and costs were recorded. Results showed significantly higher VAS scores, PCIA usage, ST-T depression, complications, longer hospital stay, and higher costs in Group I compared to Group II (P < 0.05). These findings suggest that higher CYP3A4 expression is associated with increased postoperative pain, complications, and healthcare cost. According to CYP3A4 gene expression activity, which was determined before surgery, patients with low enzyme activity metabolized local anesthetics slowly, which resulted in better analgesic effect and a longer duration of intercostal nerve block anesthesia. Owing to the impact of CYP3A4 gene expression on local anesthetic metabolism, precise intercostal nerve block anesthesia and individualized pain treatment plans could be formulated for patients undergoing radical thoracoscopic surgery for lung cancer. This may accelerate postoperative recovery from lung cancer and reduce both the length of hospital stay and hospitalization costs.

Clonal Hematopoiesis Is Associated With Long-Term Adverse Outcomes Following Cardiac Surgery

BACKGROUND

Cardiac surgery triggers sterile innate immune responses leading to postoperative complications. Clonal hematopoiesis (CH) is associated with short-term inflammation-mediated outcomes after cardiac surgery. The impact of CH on long-term postoperative outcomes remains unknown.

METHODS AND RESULTS

In this cohort study, patients undergoing elective cardiac surgery were included from January 2017 to September 2019. Patients were screened for CH using a predefined gene panel of 19 genes. Recorded clinical events were all-cause death, major adverse cardiac and cerebral events including cardiovascular death, myocardial infarction or nonscheduled coronary revascularization, stroke, and hospitalization for acute heart failure. The primary study outcome was time to a composite criterion including all-cause mortality and major adverse cardiac and cerebral events. Among 314 genotyped patients (median age: 67 years; interquartile range 59-74 years), 139 (44%) presented with CH, based on a variant allelic frequency ≥1%. Carriers of CH had a higher proportion of patients with a history of atrial fibrillation (26% for CH versus 17% for non-CH carriers, P=0.022). The most frequently mutated genes were DNMT3A, TET2, and ASXL1. After a median follow-up of 1203 [813-1435] days, the primary outcome occurred in 50 patients. After multivariable adjustment, CH was independently associated with a higher risk for the primary outcome (hazard ratio, 1.88 [95% CI, 1.05-3.41], P=0.035). Most adverse events occurred in patients carrying TET2 variants.

CONCLUSIONS

In patients undergoing cardiac surgery, CH is frequent and associated with a 2-fold increased long-term risk for major adverse clinical outcomes. CH is a novel risk factor for long-term postcardiac surgery complications and might be useful to personalize management decisions.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03376165.

Diurnal variation of postoperative delirium in elderly patients undergoing esketamine anesthesia for elective noncardiac surgery: a randomized clinical trial

BACKGROUND

Postoperative delirium (POD) is a serious and common complication. The aim of present study is to investigate the diurnal variation of POD and the effects of esketamine in elderly patients.

METHODS

A randomized, double-blind, placebo-controlled clinical trial with factorial design was conducted. Patients (aged 65 to 85 years) with normal Mini-Mental State Examination (MMSE) score were stratified by age (≤70 vs. >70) and American Society of Anesthesiologists physical status classification (Ⅱ vs. Ⅲ), then randomly assigned to either morning (08:00-12:00) or afternoon (14:00-18:00) noncardiac operation under general anesthesia with or without esketamine administration (0.2 mg/kg). The primary outcome was the incidence of POD (3-Minute Diagnostic Interview for Confusion Assessment Method-defined Delirium, 3D-CAM) on postoperative days 1, 3, and 7. The secondary outcomes were the scores of MMSE and Hospital Anxiety and Depression Scale. The intention-to-treat analysis of the outcomes were performed by generalized estimating equation.

RESULTS

Six patients who did not receive an intervention because of canceled operation were excluded after randomization. The datasets containing 426 cases were analyzed following the intention-to-treat principle after handling missing data via multiple imputation method. The incidence of POD declined from about 55% on postoperative day 1 to 31 and 18% on postoperative days 3 and 7, respectively. Afternoon operation [B=-0.583, OR (95% CI) 0.558 (0.319-0.976); P=0.041], but not esketamine, significantly decreased the incidence of POD. Both esketamine and operation time failed to significantly affect MMSE, HAD, and NRS score. There was no interaction among operation time, esketamine, and follow up time.

CONCLUSION

Elderly patients undergoing elective noncardiac surgery in the afternoon displayed lower POD incidence than those operated in the morning. A single low-dose of esketamine before general anesthesia induction failed to significantly decrease the risk of POD but decrease the risk of intraoperative hypotension and emergence agitation.

Chronotoxici-Plate Containing Droplet-Engineered Rhythmic Liver Organoids for Drug Toxicity Evaluation

The circadian clock coordinates the daily rhythmicity of biological processes, and its dysregulation is associated with various human diseases. Despite the direct targeting of rhythmic genes by many prevalent and World Health Organization (WHO) essential drugs, traditional approaches can't satisfy the need of explore multi-timepoint drug administration strategies across a wide range of drugs. Here, droplet-engineered primary liver organoids (DPLOs) are generated with rhythmic characteristics in 4 days, and developed Chronotoxici-plate as an in vitro high-throughput automated rhythmic tool for chronotherapy assessment within 7 days. Cryptochrome 1 (Cry1) is identified as a rhythmic marker in DPLOs, providing insights for rapid assessment of organoid rhythmicity. Using oxaliplatin as a representative drug, time-dependent variations are demonstrated in toxicity on the Chronotoxici-plate, highlighting the importance of considering time-dependent effects. Additionally, the role of chronobiology is underscored in primary organoid modeling. This study may provide tools for both precision chronotherapy and chronotoxicity in drug development by optimizing administration timing.

The timing of the mouse hind paw incision does not influence postsurgical pain

Chronobiological approaches have emerged as tools to study pain and inflammation. Although time-of-day effects on the expression of pain after injury have been studied, it remains unaddressed whether the timing of the injury itself can alter subsequent pain behaviors. The aim of this study was to assess postsurgical pain behaviors in a mouse hind paw incision assay in a circadian-dependent manner. Incisions were made at one of four equally spaced time points over a 24-hour period, with evoked and spontaneous pain behaviors measured using the von Frey mechanical sensitivity test, Hargreaves' radiant heat paw-withdrawal test, and the Mouse Grimace Scale. Algesiometric testing was performed in C57BL/6 mice prior to and at multiple time points after incision injury, at the same time of day, until pain resolution. No statistically significant differences were observed between groups. This study adds to the literature on circadian rhythms and their influence on pain in the pursuit of more biologically informed pre- and postoperative care.

Development and validation of a machine learning predictive model for perioperative myocardial injury in cardiac surgery with cardiopulmonary bypass

BACKGROUND

Perioperative myocardial injury (PMI) with different cut-off values has showed to be associated with different prognostic effect after cardiac surgery. Machine learning (ML) method has been widely used in perioperative risk predictions during cardiac surgery. However, the utilization of ML in PMI has not been studied yet. Therefore, we sought to develop and validate the performances of ML for PMI with different cut-off values in cardiac surgery with cardiopulmonary bypass (CPB).

METHODS

This was a second analysis of a multicenter clinical trial (OPTIMAL) and requirement for written informed consent was waived due to the retrospective design. Patients aged 18-70 undergoing elective cardiac surgery with CPB from December 2018 to April 2021 were enrolled in China. The models were developed using the data from Fuwai Hospital and externally validated by the other three cardiac centres. Traditional logistic regression (LR) and eleven ML models were constructed. The primary outcome was PMI, defined as the postoperative maximum cardiac Troponin I beyond different times of upper reference limit (40x, 70x, 100x, 130x) We measured the model performance by examining the area under the receiver operating characteristic curve (AUROC), precision-recall curve (AUPRC), and calibration brier score.

RESULTS

A total of 2983 eligible patients eventually participated in both the model development (n = 2420) and external validation (n = 563). The CatboostClassifier and RandomForestClassifier emerged as potential alternatives to the LR model for predicting PMI. The AUROC demonstrated an increase with each of the four cutoffs, peaking at 100x URL in the testing dataset and at 70x URL in the external validation dataset. However, it's worth noting that the AUPRC decreased with each cutoff increment. Additionally, the Brier loss score decreased as the cutoffs increased, reaching its lowest point at 0.16 with a 130x URL cutoff. Moreover, extended CPB time, aortic duration, elevated preoperative N-terminal brain sodium peptide, reduced preoperative neutrophil count, higher body mass index, and increased high-sensitivity C-reactive protein levels were identified as risk factors for PMI across all four cutoff values.

CONCLUSIONS

The CatboostClassifier and RandomForestClassifer algorithms could be an alternative for LR in prediction of PMI. Furthermore, preoperative higher N-terminal brain sodium peptide and lower high-sensitivity C-reactive protein were strong risk factor for PMI, the underlying mechanism require further investigation.

Integrated analysis of single-cell RNA sequencing and bulk RNA data reveals gene regulatory networks and targets in dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is a common cause of heart failure, thromboembolism, arrhythmias, and sudden cardiac death. The quality of life and long-term survival rates of patients with dilated DCM have greatly improved in recent decades. Nevertheless, the clinical prognosis for DCM patients remains unfavorable. The primary driving factors underlying the pathogenesis of DCM remain incompletely understood. The present study aimed to identify driving factors underlying the pathogenesis of DCM from the perspective of gene regulatory networks. Single-cell RNA sequencing data and bulk RNA data were obtained from the Gene Expression Omnibus (GEO) database. Differential gene analysis, single-cell genomics analysis, and functional enrichment analysis were conducted using R software. The construction of Gene Regulatory Networks was performed using Python. We used the pySCENIC method to analyze the single-cell data and identified 401 regulons. Through variance decomposition, we selected 19 regulons that showed significant responsiveness to DCM. Next, we employed the ssGSEA method to assess regulons in two bulk RNA datasets. Significant statistical differences were observed in 9 and 13 regulons in each dataset. By intersecting these differentiated regulons and identifying shared targets that appeared at least twice, we successfully pinpointed three differentially expressed targets across both datasets. In this study, we assessed and identified 19 gene regulatory networks that were responsive to the disease. Furthermore, we validated these networks using two bulk RNA datasets of DCM. The elucidation of dysregulated regulons and targets (CDKN1A, SAT1, ZFP36) enhances the molecular understanding of DCM, aiding in the development of tailored therapies for patients.

Hybrid feature selection in a machine learning predictive model for perioperative myocardial injury in noncoronary cardiac surgery with cardiopulmonary bypass

BACKGROUND

Perioperative myocardial injury (PMI) is associated with increased mobility and mortality after noncoronary cardiac surgery. However, limited studies have developed a predictive model for PMI. Therefore, we used hybrid feature selection (FS) methods to establish a predictive model for PMI in noncoronary cardiac surgery with cardiopulmonary bypass (CPB).

METHODS

This was a single-center retrospective study conducted at the Fuwai Hospital in China. Patients aged 18-70 years who underwent elective noncoronary surgery with CPB at our institution from December 2018 to April 2021 were enrolled. The primary outcome was PMI, defined as the postoperative cardiac troponin I (cTnI) levels exceeding 220 times of upper reference limit (URL). Statistical analyses were conducted by Python (Python Software Foundation, version 3.9.7 and integrated development environment Jupyter Notebook 1.1.0) and SPSS software version 26.0 (IBM Corp., Armonk, New York, USA).

RESULTS

A total of 1130 patients were eventually eligible for this study. The incidence of PMI was 20.3% (229/1130) in the overall patients, 20.6% (163/791) in the training dataset, and 19.5% (66/339) in the testing dataset. The logistic regression model performed the best AUC of 0.6893 (95 CI%: 0.6371-0.7382) by the traditional selection method, and the random forest model performed the best AUC of 0.6937 (95 CI%: 0.6416-0.7423) by the union of Wrapper and Embedded method, and the CatBoost model performed the best AUC of 0.6828 (95 CI%: 0.6304-0.7320) by the union of Embedded and forward logistic regression technique, and the Naïve Bayes model achieved the best AUC with 0.7254 (95 CI%: 0.6746-0.7723) by forwarding logistic regression method. Moreover, the decision tree, KNeighborsClassifier, and support vector machine models performed the worse AUC in all selection forms. Furthermore, the SHapley Additive exPlanations plot showed that prolonged CPB, aortic clamp time, and preoperative low platelets count were strongly related to the PMI risk.

CONCLUSIONS

In total, four category feature selection methods were utilized, comprising five individual selection techniques and 15 combined methods. Notably, the combination of logistic regression and embedded methods demonstrated outstanding performance in predicting PMI risk. We also concluded that the machine learning model, including random forest, catboost, and Naive Bayes, were suitable candidates for establishing PMI predictive model. Nevertheless, additional investigation and validation are imperative for substantiating these finding.

tauFisher predicts circadian time from a single sample of bulk and single-cell pseudobulk transcriptomic data

As the circadian clock regulates fundamental biological processes, disrupted clocks are often observed in patients and diseased tissues. Determining the circadian time of the patient or the tissue of focus is essential in circadian medicine and research. Here we present tauFisher, a computational pipeline that accurately predicts circadian time from a single transcriptomic sample by finding correlations between rhythmic genes within the sample. We demonstrate tauFisher's performance in adding timestamps to both bulk and single-cell transcriptomic samples collected from multiple tissue types and experimental settings. Application of tauFisher at a cell-type level in a single-cell RNAseq dataset collected from mouse dermal skin implies that greater circadian phase heterogeneity may explain the dampened rhythm of collective core clock gene expression in dermal immune cells compared to dermal fibroblasts. Given its robustness and generalizability across assay platforms, experimental setups, and tissue types, as well as its potential application in single-cell RNAseq data analysis, tauFisher is a promising tool that facilitates circadian medicine and research.

Circadian rhythms in solid organ transplantation

Circadian rhythms are daily cycles in physiology that can affect medical interventions. This review considers how these rhythms may relate to solid organ transplantation. It begins by summarizing the mechanism for circadian rhythm generation known as the molecular clock, and basic research connecting the clock to biological activities germane to organ acceptance. Next follows a review of clinical evidence relating time of day to adverse transplantation outcomes. The concluding section discusses knowledge gaps and practical areas where applying circadian biology might improve transplantation success.

Graphene-based field-effect transistors for biosensing: where is the field heading to?

Two-dimensional (2D) materials hold great promise for future applications, notably their use as biosensing channels in the field-effect transistor (FET) configuration. On the road to implementing one of the most widely used 2D materials, graphene, in FETs for biosensing, key issues such as operation conditions, sensitivity, selectivity, reportability, and economic viability have to be considered and addressed correctly. As the detection of bioreceptor-analyte binding events using a graphene-based FET (gFET) biosensor transducer is due to either graphene doping and/or electrostatic gating effects with resulting modulation of the electrical transistor characteristics, the gFET configuration as well as the surface ligands to be used have an important influence on the sensor performance. While the use of back-gating still grabs attention among the sensor community, top-gated and liquid-gated versions have started to dominate this area. The latest efforts on gFET designs for the sensing of nucleic acids, proteins and virus particles in different biofluids are presented herewith, highlighting the strategies presently engaged around gFET design and choosing the right bioreceptor for relevant biomarkers.

The Effects of Daytime Variation on Short-term Outcomes of Patients Undergoing Off-Pump Coronary Artery Bypass Grafting

OBJECTIVE

To evaluate the effects of time of surgery on the short-term outcomes of patients undergoing off-pump coronary artery bypass grafting (OPCABG).

DESIGN

A retrospective cohort study.

SETTING

A single large-volume cardiovascular center.

PATIENTS

Patients undergoing elective OPCABG between September 2019 and July 2022.

INTERVENTIONS

Patients were divided into the following 2 groups according to the start time of surgery: morning (AM group, before 11 AM) and afternoon (PM group, after 11 AM). Propensity-score matching (PSM) with a 1:1 matching ratio was used to create comparable cohorts.

MEASUREMENTS AND MAIN RESULTS

The primary endpoint was the composite incidence of mortality and morbidities during hospitalization. Secondary endpoints included postoperative bleeding and transfusion, mechanical ventilation duration (MVD), and lengths of stay (LOS) in the intensive care unit (ICU) and hospital. From a consecutive series of 1,039 patients, PSM yielded 317 well-matched pairs. There was no difference in the composite incidence of in-hospital mortality and morbidities between the AM and PM groups (16.4% v 17.4%, p = 0.832). However, patients in the PM group were associated with less postoperative blood loss over the first 24 hours (470 v 540 mL, p = 0.002), decreased MVD (14 v 16 hours, p < 0.001), and shorter LOS in ICU (46 v 68 hours, p = 0.002) compared to patients in AM group.

CONCLUSIONS

The current study suggested a lack of relevance regarding the time of surgery with in-hospital mortality and morbidities in patients undergoing OPCABG.

Morning or Afternoon Scheduling for Elective Coronary Artery Bypass Surgery: Influence of Longer Fasting Periods from Metabolic and Hemodynamic Perspectives

BACKGROUND

Prolonged preoperative fasting may worsen postoperative outcomes. Cardiac surgery has higher perioperative risk, and longer fasting periods may be not well-tolerated. We analysed the postoperative metabolic and hemodynamic variables in patients undergoing elective coronary artery bypass grafting (CABG) according to their morning or afternoon schedule.

METHODS

Single-centre retrospective study at University teaching hospital (1-year data collection from electronic medical records). Using a mixed-effects linear regression model adjusted for several covariates, we compared metabolic (lactatemia, pH, and base deficit [BD]) and haemodynamic values (patients on vasoactive support, and vasoactive inotropic score [VIS]) at 7 prespecified time-points (admission to intensive care, and 1st, 3rd, 6th, 12th, 18th, and 24th postoperative hours).

RESULTS

339 patients (n = 176 morning, n = 163 afternoon) were included. Arterial lactatemia and BD were similar (overall P = 0.11 and P = 0.84, respectively), while pH was significantly lower in the morning group (overall P < 0.05; mean difference -0.01). Postoperative urine output, fluid balance, mean arterial pressure, and central venous pressure were similar (P = 0.59, P = 0.96, P = 0.58 and P = 0.53, respectively). A subgroup analysis of patients with diabetes (n = 54 morning, n = 45 afternoon) confirmed the same findings. The VIS values and the proportion of patients on vasoactive support was higher in the morning cases at the 18th (P = 0.002 and p=0.04, respectively) and 24th postoperative hours (P = 0.003 and P = 0.04, respectively). Mean intensive care length of stay was 1.94 ± 1.36 days versus 2.48 ± 2.72 days for the afternoon and morning cases, respectively (P = 0.02).

CONCLUSIONS

Patients undergoing elective CABG showed similar or better metabolic and hemodynamic profiles when scheduled for afternoon surgery.

Circadian Influences on Myocardial Ischemia-Reperfusion Injury and Heart Failure

The impact of circadian rhythms on cardiovascular function and disease development is well established, with numerous studies in genetically modified animals emphasizing the circadian molecular clock's significance in the pathogenesis and pathophysiology of myocardial ischemia and heart failure progression. However, translational preclinical studies targeting the heart's circadian biology are just now emerging and are leading to the development of a novel field of medicine termed circadian medicine. In this review, we explore circadian molecular mechanisms and novel therapies, including (1) intense light, (2) small molecules modulating the circadian mechanism, and (3) chronotherapies such as cardiovascular drugs and meal timings. These promise significant clinical translation in circadian medicine for cardiovascular disease. (4) Additionally, we address the differential functioning of the circadian mechanism in males versus females, emphasizing the consideration of biological sex, gender, and aging in circadian therapies for cardiovascular disease.

The effect of surgery started at different time point during the day on the clinical outcomes of mitral valve surgery

Background

The clinical prognosis of mitral valve surgery at morning, afternoon, and evening is not yet clear. The aim of the study is to investigate the impact of different time periods of surgery in the morning, afternoon and evening on the short-term and long-term results of mitral valve surgery.

Methods

From January 2018 to December 2020, 947 patients with mitral valve surgery in our department were selected. These patients were divided into 3 groups according to the starting time of surgery. Morning group (operation start time 8:00-10:30, n = 231), afternoon group (operation start time 12:00-14:30, n = 543), and evening group (operation start time 17:30-20:00, n = 173). The short-term and long-term results of the three groups were compared.

Results

There were no significant difference in the long-term mortality, long-term risk of stroke and reoperation. And there were no significant difference in in-hospital outcomes, including mortality, stroke, cardiopulmonary bypass time, aortic cross clamp time, mitral valve repair convert to mitral valve replacement, number of aortic cross clamp ≥2 times, unplanned secondary surgery during hospitalization (including thoracotomy hemostasis, thoracotomy exploration, redo mitral valve surgery, and debridement), intra-aortic balloon pump, extracorporeal membrane oxygenation, continuous renal replacement therapy, mechanical ventilation time, and intensive care unit length of stay.

Conclusion

There is no significant difference in the risk of short-term and long-term survival and adverse events after mitral valve surgery at different time periods in the morning, afternoon, and evening. Mitral valve surgery at night is safe.

Analysis and identification of oxidative stress-ferroptosis related biomarkers in ischemic stroke

Studies have shown that a series of molecular events caused by oxidative stress is associated with ferroptosis and oxidation after ischemic stroke (IS). Differential analysis was performed to identify differentially expressed mRNA (DEmRNAs) between IS and control groups. Critical module genes were identified using weighted gene co-expression network analysis (WGCNA). DEmRNAs, critical module genes, oxidative stress-related genes (ORGs), and ferroptosis-related genes (FRGs) were crossed to screen for intersection mRNAs. Candidate mRNAs were screened based on the protein-protein interaction (PPI) network and the MCODE plug-in. Biomarkers were identified based on two types of machine learning algorithms, and the intersection was obtained. Functional items and related pathways of the biomarkers were identified using gene set enrichment analysis (GSEA). Finally, single-sample GSEA (ssGSEA) and Wilcoxon tests were used to identify differential immune cells. An miRNA-mRNA-TF network was created. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to verify the expression levels of biomarkers in the IS and control groups. There were 8287 DE mRNAs between the IS and control groups. The genes in the turquoise module were selected as critical module genes for IS. Thirty intersecting mRNAs were screened for overlaps. Seventeen candidate mRNAs were also identified. Four biomarkers (CDKN1A, GPX4, PRDX1, and PRDX6) were identified using two types of machine-learning algorithms. GSEA results indicated that the biomarkers were associated with steroid biosynthesis. Nine types of immune cells (activated B cells and neutrophils) were markedly different between the IS and control groups. We identified 3747 miRNA-mRNA-TF regulatory pairs in the miRNA-mRNA-TF regulatory network, including hsa-miR-4469-CDKN1A-BACH2 and hsa-miR-188-3p-GPX4-ATF2. CDKN1A, PRDX1, and PRDX6 were upregulated in IS samples compared with control samples. This study suggests that four biomarkers (CDKN1A, GPX4, PRDX1, and PRDX6) are significantly associated with IS. This study provides a new reference for the diagnosis and treatment of IS.

Effects of volatile anesthetics on circadian rhythm in mice: a comparative study of sevoflurane, desflurane, and isoflurane

PURPOSE

Volatile anesthetics affect the circadian rhythm of mammals, although the effects of different types of anesthetics are unclear. Here, we anesthetized mice using several volatile anesthetics at two different times during the day. Our objective was to compare the effects of these anesthetics on circadian rhythm.

METHODS

Male adult C57BL/6 J mice were divided into eight groups (n = 8 each) based on the anesthetic (sevoflurane, desflurane, isoflurane, or no anesthesia) and anesthesia time (Zeitgeber time [ZT] 6-12 or ZT18-24). Mice were anesthetized for 6 h using a 0.5 minimum alveolar concentration (MAC) dose under constant dark conditions. The difference between the start of the active phase before and after anesthesia was measured as a phase shift. Clock genes were measured by polymerase chain reaction in suprachiasmatic nucleus (SCN) samples removed from mouse brain after anesthesia (n = 8-9 each).

RESULTS

Phase shift after anesthesia at ZT6-12 using sevoflurane (- 0.49 h) was smaller compared with desflurane (- 1.1 h) and isoflurane (- 1.4 h) (p < 0.05). Clock mRNA (ZT6-12, p < 0.05) and Per2 mRNA (ZT18-24, p < 0.05) expression were different between the groups after anesthesia.

CONCLUSION

0.5 MAC sevoflurane anesthesia administered during the late inactive to early active phase has less impact on the phase shift of circadian rhythm than desflurane and isoflurane. This may be due to differences in the effects of volatile anesthetics on the expression of clock genes in the SCN, the master clock of the circadian rhythm.

The Molecular Circadian Clock Is a Target of Anti-cancer Translation Inhibitors

Circadian-paced biological processes are key to physiology and required for metabolic, immunologic, and cardiovascular homeostasis. Core circadian clock components are transcription factors whose half-life is precisely regulated, thereby controlling the intrinsic cellular circadian clock. Genetic disruption of molecular clock components generally leads to marked pathological events phenotypically affecting behavior and multiple aspects of physiology. Using a transcriptional signature similarity approach, we identified anti-cancer protein synthesis inhibitors as potent modulators of the cardiomyocyte molecular clock. Eukaryotic protein translation inhibitors, ranging from translation initiation (rocaglates, 4-EGI1, etc.) to ribosomal elongation inhibitors (homoharringtonine, puromycin, etc.), were found to potently ablate protein abundance of REV-ERBα, a repressive nuclear receptor and component of the molecular clock. These inhibitory effects were observed both in vitro and in vivo and could be extended to PER2, another component of the molecular clock. Taken together, our observations suggest that the activity spectrum of protein synthesis inhibitors, whose clinical use is contemplated not only in cancers but also in viral infections, must be extended to circadian rhythm disruption, with potential beneficial or iatrogenic effects upon acute or prolonged administration.

Time-of-day-dependent variation of the human liver transcriptome and metabolome is disrupted in MASLD

Background & Aims

Liver homeostasis is ensured in part by time-of-day-dependent processes, many of them being paced by the molecular circadian clock. Liver functions are compromised in metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH), and clock disruption increases susceptibility to MASLD progression in rodent models. We therefore investigated whether the time-of-day-dependent transcriptome and metabolome are significantly altered in human steatotic and MASH livers.

Methods

Liver biopsies, collected within an 8 h-window from a carefully phenotyped cohort of 290 patients and histologically diagnosed to be either normal, steatotic or MASH hepatic tissues, were analyzed by RNA sequencing and unbiased metabolomic approaches. Time-of-day-dependent gene expression patterns and metabolomes were identified and compared between histologically normal, steatotic and MASH livers.

Results

Herein, we provide a first-of-its-kind report of a daytime-resolved human liver transcriptome-metabolome and associated alterations in MASLD. Transcriptomic analysis showed a robustness of core molecular clock components in steatotic and MASH livers. It also revealed stage-specific, time-of-day-dependent alterations of hundreds of transcripts involved in cell-to-cell communication, intracellular signaling and metabolism. Similarly, rhythmic amino acid and lipid metabolomes were affected in pathological livers. Both TNFα and PPARγ signaling were predicted as important contributors to altered rhythmicity.

Conclusion

MASLD progression to MASH perturbs time-of-day-dependent processes in human livers, while the differential expression of core molecular clock components is maintained.

Impact and implications

This work characterizes the rhythmic patterns of the transcriptome and metabolome in the human liver. Using a cohort of well-phenotyped patients (n = 290) for whom the time-of-day at biopsy collection was known, we show that time-of-day variations observed in histologically normal livers are gradually perturbed in liver steatosis and metabolic dysfunction-associated steatohepatitis. Importantly, these observations, albeit obtained across a restricted time window, provide further support for preclinical studies demonstrating alterations of rhythmic patterns in diseased livers. On a practical note, this study indicates the importance of considering time-of-day as a critical biological variable which may significantly affect data interpretation in animal and human studies of liver diseases.

The Cardiac Circadian Clock: Implications for Cardiovascular Disease and its Treatment

Virtually all aspects of physiology fluctuate with respect to the time of day. This is beautifully exemplified by cardiovascular physiology, for which blood pressure and electrophysiology exhibit robust diurnal oscillations. At molecular/biochemical levels (eg, transcription, translation, signaling, metabolism), cardiovascular-relevant tissues (such as the heart) are profoundly different during the day vs the night. Unfortunately, this in turn contributes toward 24-hour rhythms in both risk of adverse event onset (eg, arrhythmias, myocardial infarction) and pathogenesis severity (eg, extent of ischemic damage). Accumulating evidence indicates that cell-autonomous timekeeping mechanisms, termed circadian clocks, temporally govern biological processes known to play critical roles in cardiovascular function/dysfunction. In this paper, a comprehensive review of our current understanding of the cardiomyocyte circadian clock during both health and disease is detailed. Unprecedented basic, translational, and epidemiologic studies support a need to implement chronobiological considerations in strategies designed for both prevention and treatment of cardiovascular disease.

Daytime variation in non-cardiac surgery impacts the recovery after general anesthesia

BACKGROUND

Circadian rhythm involved with physiology has been reported to affect pharmacokinetics or pharmacodynamics. We hypothesized that circadian variations in physiology disturb anesthesia and eventually affect recovery after anesthesia.

METHODS

A retrospective cohort study initially included 107,406 patients (1 June 2016-6 June 2021). Patients were classified into morning or afternoon surgery groups. The primary outcome was daytime variation in PACU (post-anesthesia care unit) recovery time and Steward score. Inverse probability weighting (IPW) approach based on propensity score and univariable/multivariable linear regression were used to estimate this outcome.

RESULTS

Of 28,074 patients, 13,418 (48%) patients underwent morning surgeries, and 14,656 (52%) patients underwent afternoon surgeries. LOWESS curves and IPW illustrated daytime variation in PACU recovery time and Steward score. Before adjustment, compared to morning surgery group, afternoon surgery group had less PACU recovery time (median [interquartile range], 57 [46, 70] vs. 54 [43, 66], p < 0.001) and a higher Steward score (5.62 [5.61, 5.63] vs. 5.66 [5.65, 5.67], p < 0.001). After adjustment, compared to morning surgery group, afternoon surgery group had less PACU recovery time (58 [46, 70] vs. 54 [43, 66], p < 0.001). In multivariable linear regression, morning surgery is statistically associated with an increased PACU recovery time (coefficient, -3.20; 95% confidence interval, -3.55 to -2.86).

Among non-cardiac surgeries, daytime variation might affect recovery after general anesthesia. These findings indicate that the timing of surgery improves recovery after general anesthesia, with afternoon surgery providing protection.KEY MESSAGESIn this retrospective cohort study of 28,074 participants, the afternoon surgery group has a higher Steward score than the morning surgery group.In multivariable linear regression, morning surgery is statistically associated with an increased PACU recovery time.Among non-cardiac surgeries, daytime variation affects the recovery after general anesthesia, with afternoon surgery providing protection.

Circadian Disruption and the Molecular Clock in Atherosclerosis and Hypertension

Circadian rhythms are crucial for maintaining vascular function and disruption of these rhythms are associated with negative health outcomes including cardiovascular disease and hypertension. Circadian rhythms are regulated by the central clock within the suprachiasmatic nucleus of the hypothalamus and peripheral clocks located in nearly every cell type in the body, including cells within the heart and vasculature. In this review, we summarize the most recent preclinical and clinical research linking circadian disruption, with a focus on molecular circadian clock mechanisms, in atherosclerosis and hypertension. Furthermore, we provide insight into potential future chronotherapeutics for hypertension and vascular disease. A better understanding of the influence of daily rhythms in behaviour, such as sleep/wake cycles, feeding, and physical activity, as well as the endogenous circadian system on cardiovascular risk will help pave the way for targeted approaches in atherosclerosis and hypertension treatment/prevention.

Hypoxia-induced signaling in the cardiovascular system: pathogenesis and therapeutic targets

Hypoxia, characterized by reduced oxygen concentration, is a significant stressor that affects the survival of aerobic species and plays a prominent role in cardiovascular diseases. From the research history and milestone events related to hypoxia in cardiovascular development and diseases, The "hypoxia-inducible factors (HIFs) switch" can be observed from both temporal and spatial perspectives, encompassing the occurrence and progression of hypoxia (gradual decline in oxygen concentration), the acute and chronic manifestations of hypoxia, and the geographical characteristics of hypoxia (natural selection at high altitudes). Furthermore, hypoxia signaling pathways are associated with natural rhythms, such as diurnal and hibernation processes. In addition to innate factors and natural selection, it has been found that epigenetics, as a postnatal factor, profoundly influences the hypoxic response and progression within the cardiovascular system. Within this intricate process, interactions between different tissues and organs within the cardiovascular system and other systems in the context of hypoxia signaling pathways have been established. Thus, it is the time to summarize and to construct a multi-level regulatory framework of hypoxia signaling and mechanisms in cardiovascular diseases for developing more therapeutic targets and make reasonable advancements in clinical research, including FDA-approved drugs and ongoing clinical trials, to guide future clinical practice in the field of hypoxia signaling in cardiovascular diseases.

Inhibiting Rev-erbα-mediated ferroptosis alleviates susceptibility to myocardial ischemia-reperfusion injury in type 2 diabetes

The complex progression of type-2 diabetes (T2DM) may result in increased susceptibility to myocardial ischemia-reperfusion (IR) injury. IR injuries in multiple organs involves ferroptosis. Recently, the clock gene Rev-erbα has aroused considerable interest as a novel therapeutic target for metabolic and ischemic heart diseases. Herein, we investigated the roles of Rev-erbα and ferroptosis in myocardial IR injury during T2DM and its potential mechanisms. A T2DM model, myocardial IR and a tissue-specific Rev-erbα-/- mouse in vivo were established, and a high-fat high glucose environment with hypoxia-reoxygenation (HFHG/HR) in H9c2 were also performed. After myocardial IR, glycolipid profiles, creatine kinase-MB, AI, and the expression of Rev-erbα and ferroptosis-related proteins were increased in diabetic rats with impaired cardiac function compared to non-diabetic rats, regardless of the time at which IR was induced. The ferroptosis inhibitor ferrostatin-1 decreased AI in diabetic rats given IR and LPO levels in cells treated with HFHG/HR, as well as the expression of Rev-erbα and ACSL4. The ferroptosis inducer erastin increased AI and LPO levels and ACSL4 expression. Treatment with the circadian regulator nobiletin and genetically targeting Rev-erbα via siRNA or CRISPR/Cas9 technology both protected against severe myocardial injury and decreased Rev-erbα and ACSL4 expression, compared to the respective controls. Taken together, these data suggest that ferroptosis is involved in the susceptibility to myocardial IR injury during T2DM, and that targeting Rev-erbα could alleviate myocardial IR injury by inhibiting ferroptosis.

tauFisher accurately predicts circadian time from a single sample of bulk and single-cell transcriptomic data

As the circadian clock regulates fundamental biological processes, disrupted clocks are often observed in patients and diseased tissues. Determining the circadian time of the patient or the tissue of focus is essential in circadian medicine and research. Here we present tau-Fisher, a computational pipeline that accurately predicts circadian time from a single transcriptomic sample by finding correlations between rhythmic genes within the sample. We demonstrate tauFisher's out-standing performance in both bulk and single-cell transcriptomic data collected from multiple tissue types and experimental settings. Application of tauFisher at a cell-type level in a single-cell RNA-seq dataset collected from mouse dermal skin implies that greater circadian phase heterogeneity may explain the dampened rhythm of collective core clock gene expression in dermal immune cells compared to dermal fibroblasts. Given its robustness and generalizability across assay platforms, experimental setups, and tissue types, as well as its potential application in single-cell RNA-seq data analysis, tauFisher is a promising tool that facilitates circadian medicine and research.

Predictive value of perioperative procalcitonin, C reactive protein and high-sensitivity C reactive protein for the risk of postoperative complications after non-cardiac surgery in elderly patients: a nested case-control study

OBJECTIVE

Little is known about the correlation between perioperative concentrations of inflammatory biomarkers and postoperative complications. This study explored whether the plasma concentrations and perioperative changes of procalcitonin (PCT), C reactive protein (CRP) and high-sensitivity CRP (hsCRP) could predict the risk of postoperative morbidity in elderly patients undergoing elective non-cardiac surgery.

DESIGN

A nested case-control study.

SETTING

A tertiary hospital in China.

PARTICIPANTS

A total of 498 patients aged ≥65 years from a prospective cohort who underwent elective non-cardiac surgery between June 2020 and April 2021.

PRIMARY OUTCOME MEASURES

The primary outcomes were the efficacy of plasma concentrations of PCT, CRP and hsCRP in predicting the risk of Clavien-Dindo Classification (CDC) ≥grade 3 and major complications. The major complications included mortality, an intensive care unit stay length >24 hour, cardiovascular events, acute kidney injury, postoperative cognitive dysfunction and infections.

RESULTS

For major complications, the area under the curve (AUC) (95% CI) of PCT-24 hours, PCT change and PCT change rate were 0.750 (0.698 to 0.803), 0.740 (0.686 to 0.795) and 0.711 (0.651 to 0.771), respectively. The AUC (95% CI) of CRP-24 hours, CRP change, CRP change rate and hsCRP baseline were 0.835 (0.789 to 0.881), 0.818 (0.770 to 0.867), 0.691 (0.625 to 0.756) and 0.616 (0.554 to 0.678), respectively. For complications ≥CDC grade 3, the AUC (95% CI) of PCT-24 hours, PCT change and PCT change rate were 0.662 (0.543 to 0.780), 0.643 (0.514 to 0.772) and 0.627 (0.494 to 0.761), respectively. The AUC (95% CI) of CRP-24 hours and hsCRP baseline were 0.649 (0.527 to 0.771) and 0.639 (0.530 to 0.748), respectively.

CONCLUSIONS

PCT-24 hours, CRP-24 hours, the change of perioperative PCT and CRP were valuable predictors of major complications occurring within 30 days after non-cardiac surgery in the elderly.

TRIAL REGISTRATION NUMBER

China Clinical Trial Registry: ChiCTR1900026223.

Time-related variations in viability of random pattern skin flaps: An experimental study in rats

Chronobiological variations are in the fabric of life. The first ideas regarding the possible effects of circadian rhythm on surgical outcomes were published in the early 2000s. Some studies support and oppose this idea. The lack of experimental evidence in a controlled setting has led to this study. This study aimed to explore the chronobiological implications of surgical outcomes. The rats were divided into four groups. A random pattern dorsal skin flaps were elevated in all groups at six h intervals. Flap necrosis rates and melatonin, oxidant, and antioxidant factors were studied. Flap survival was better in the 06:00 h group. The flap necrosis was higher in the 18:00 h group. Some of the biochemical parameters displayed circadian variations. As an independent variable, the time of surgical intervention changed the flap survival rates. It should be noted that the study was held in a nocturnal animal model thus the pattern of flap survival can be in reversed fashion in a clinical scenario. This study is the first experimental evidence for "Chronosurgery" in a controlled setting. Further studies in all aspects of surgical disciplines are required.

Targeting mitochondrial circadian rhythms: The potential intervention strategies of Traditional Chinese medicine for myocardial ischaemia‒reperfusion injury

Coronary artery disease has one of the highest mortality rates in the country, and methods such as thrombolysis and percutaneous coronary intervention (PCI) can effectively improve symptoms and reduce mortality, but most patients still experience symptoms such as chest pain after PCI, which seriously affects their quality of life and increases the incidence of adverse cardiovascular events (myocardial ischaemiareperfusion injury, MIRI). MIRI has been shown to be closely associated with circadian rhythm disorders and mitochondrial dysfunction. Mitochondria are a key component in the maintenance of normal cardiac function, and new research shows that mitochondria have circadian properties. Traditional Chinese medicine (TCM), as a traditional therapeutic approach characterised by a holistic concept and evidence-based treatment, has significant advantages in the treatment of MIRI, and there is an interaction between the yin-yang theory of TCM and the circadian rhythm of Western medicine at various levels. This paper reviews the clinical evidence for the treatment of MIRI in TCM, basic experimental studies on the alleviation of MIRI by TCM through the regulation of mitochondria, the important role of circadian rhythms in the pathophysiology of MIRI, and the potential mechanisms by which TCM regulates mitochondrial circadian rhythms to alleviate MIRI through the regulation of the biological clock transcription factor. It is hoped that this review will provide new insights into the clinical management, basic research and development of drugs to treat MIRI.

The Role of the Circadian Rhythm in Dyslipidaemia and Vascular Inflammation Leading to Atherosclerosis

Cardiovascular diseases (CVD) are among the leading causes of death worldwide. Many lines of evidence suggest that the disturbances in circadian rhythm are responsible for the development of CVDs; however, circadian misalignment is not yet a treatable trait in clinical practice. The circadian rhythm is controlled by the central clock located in the suprachiasmatic nucleus and clock genes (molecular clock) located in all cells. Dyslipidaemia and vascular inflammation are two hallmarks of atherosclerosis and numerous experimental studies conclude that they are under direct influence by both central and molecular clocks. This review will summarise the results of experimental studies on lipid metabolism, vascular inflammation and circadian rhythm, and translate them into the pathophysiology of atherosclerosis and cardiovascular disease. We discuss the effect of time-respected administration of medications in cardiovascular medicine. We review the evidence on the effect of bright light and melatonin on cardiovascular health, lipid metabolism and vascular inflammation. Finally, we suggest an agenda for future research and recommend on clinical practice.

Denervation aggravates renal ischemia reperfusion injury via BMAL1-mediated Nrf2/ARE pathway

AIM

To explore the change of clock gene rhythm under renal denervation (RDN) and its effect on renal function and oxidative stress during renal ischemia-reperfusion (IR) injury.

METHOD

C57/BL6 mice were randomly divided into 4 groups at daytime 7 A M (zeitgeber time [ZT] 0) or at nighttime 7 P M (ZT12) in respectively: Sham (S) group, RDN group, IR group and RDN + IR (DIR) group. Renal pathological and functional changes were assessed by H&E staining, and serum creatinine, urea nitrogen and neutrophil gelatinase-associated lipocalin levels. Renal oxidative stress was detected by SOD and MDA levels, and renal inflammation was measured by IL-6, IL-17 A F and TNF-ɑ levels. BMAL1, CLOCK, Nrf2 and HO-1 mRNA and protein expressions were tested by qPCR and Western Blot.

RESULT

Compared with S groups, the rhythm of BMAL1, CLOCK and Nrf2 genes in the kidney were disordered in RDN groups, while renal pathological and functional indexes did not change significantly. Compared with IR groups, renal pathological and functional indexes were significantly higher in the DIR groups, as well as oxidative stress and inflammation in renal tissues. The nocturnal IR injury in the RDN kidney was the worst while the BMAL1, Nrf2 and HO-1 expressions were the highest. In DIR groups, renal injury was aggravated after the Brusatol treatment, but there was no significant improvement after the t-BHQ treatment at night, which might be consistent with the changes of Nrf2 and HO-1 protein expressions.

CONCLUSION

RDN lead to the disruption of BMAL1-mediated Nrf2 rhythm accumulation in the kidney, which reduced the renal ability to resist oxidative stress and inflammation, due to the impaired effect of activating Nrf2/ARE pathway in renal IR injury at nighttime.

Time-of-day discrepancy for the long-term surgical outcome of patients with aortic dissection

OBJECTIVES

It has been suggested that the time of day when cardiovascular surgery is performed may affect the surgery outcomes. This study investigated whether there was a difference in risk-adjusted mortality and morbidity outcomes between patients undergoing acute aortic dissection (AAD) during the day or the night.

METHODS

Consecutive patients who had undergone Stanford A AAD surgery were enrolled between 2016 and 2020. In the daytime group, surgery was performed between 08:00 and 20:00, and in the nighttime group between 20:00 and 8:00. The primary outcome was in-hospital overall mortality, and the secondary outcomes were overall mortality within a median follow-up time of 35.2 (17.0, 53.5) months and the occurrence of re-entry tears and major bleeding.

RESULTS

A total of 925 patients were enrolled. The primary outcome of in-hospital overall mortality did not differ significantly between patients who received daytime or nighttime surgery. Similarly, the secondary outcomes of overall mortality during the follow-up and incidence of re-entry tears and major bleeding did not differ significantly between the groups. Subgroup analysis was also performed according to the surgery type (modified triple-branched stent graft implantation or frozen elephant trunk implantation) and surgical approach (partial upper sternotomy or full median sternotomy) confirming that the time of surgery did not significantly influence the outcomes. Cox regression analysis showed that time from onset to admission (P = 0.036) and time from the onset to surgery (P = 0.045) were significant risk factors for increased mortality during follow-up.

CONCLUSIONS

The time of day when thoracotomy was performed did not significantly affect the clinical outcome and is therefore not a consideration for the improvement of outcome in Stanford A AAD patients.

Inhibition of mPGES-2 ameliorates NASH by activating NR1D1 via heme

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD), a complex metabolic syndrome, has limited therapeutic options. Microsomal prostaglandin E synthase-2 (mPGES-2) was originally discovered as a prostaglandin E 2 (PGE 2 ) synthase; however, it does not produce PGE 2 in the liver. Moreover, the role of mPGES-2 in NAFLD remains undefined. Herein, we aimed to determine the function and mechanism of mPGES-2 in liver steatosis and steatohepatitis.

APPROACH AND RESULTS

To evaluate the role of mPGES-2 in NAFLD, whole-body or hepatocyte-specific mPGES-2-deficient mice fed a high-fat or methionine-choline-deficient diet were used. Compared with control mice, mPGES-2-deficient mice showed reduced hepatic lipid accumulation, along with ameliorated liver injury, inflammation, and fibrosis. Furthermore, the protective effect of mPGES-2 deficiency against NAFLD was dependent on decreased cytochrome P450 4A14 and increased acyl-CoA thioesterase 4 levels regulated by the heme receptor nuclear receptor subfamily 1 group D member 1 (NR1D1), but not PGE 2 . Heme regulated the increased NR1D1 activity mediated by mPGES-2 deficiency. Further, we confirmed the protective role of the mPGES-2 inhibitor SZ0232 in NAFLD therapy.

CONCLUSION

Our study indicates the pathogenic role of mPGES-2 and outlines the mechanism in mediating NAFLD, thereby highlighting the therapeutic potential of mPGES-2 inhibition in liver steatosis and steatohepatitis.

Risk factors for postoperative myocardial injury-related cardiogenic shock in patients undergoing cardiac surgery

BACKGROUND

Myocardial injury-related cardiogenic shock (MICS) is significantly associated with poor outcomes in patients after cardiac surgery. Herein, we aimed to investigate the risk factor for postoperative MICS.

METHODS

We performed a case-control study on 792 patients undergoing cardiac surgery from 2016 to 2019, including 172 patients with postoperative MICS and 620 age- and sex-matched controls. MICS was defined as composite criteria: a cardiac index of < 2.2 L/m²/min, arterial lactate levels of > 5 mmol/L at the end of the surgery, a vasoactive-inotropic score of > 40 at the end of the surgery, and a cardiac troponin T (cTnT) level of > 0.8 µg/L on postoperative day 1 (POD1) with an increase of > 10% on POD 2.

RESULTS

A total of 4671 patients who underwent cardiac surgery in our hospital between 2016 and 2019 were included; of these, 172 (3.68%) had MICS and the remaining 4499 did not. For investigating the risk factors, we selected 620 age- and sex-matched controls. In the univariate analysis, MICS was significantly associated with death (P < 0.05), extracorporeal membrane oxygenation (P < 0.05), continuous renal replacement therapy (P < 0.01), and ventricular arrhythmias (P < 0.05). Multivariable logistic regression analysis revealed that diabetes mellitus (OR:8.11, 95% CI: 3.52-18.66, P < 0.05) and a cardiopulmonary bypass (CPB) time of > 2 h (OR: 3.16, 95% CI: 1.94-5.15, P < 0.05) were associated with postoperative MICS. Moreover, long-time administration of preoperative calcium channel blocker (CCB) was associated with a less incidence of MICS (OR: 0.11, 95% CI: 0.05-0.27, P < 0.05).

CONCLUSIONS

Postoperative MICS is significantly associated with poor outcomes. Diabetes mellitus and long CPB time are associated with MICS. Preoperative CCB administration is associated with less incidence of MICS.

The impact of time-of-day reperfusion on remote ischemic conditioning in ST-elevation myocardial infarction: a RIC-STEMI substudy

Daytime variation affects the tolerance of cardiomyocytes to ischemia-reperfusion injury (IRI). This study aims to evaluate the impact of time-of-day reperfusion on clinical outcomes of remote ischemic conditioning (RIC) as an adjuvant to primary percutaneous coronary intervention(PPCI) in ST-elevation myocardial infarction(STEMI) patients. A post-hoc analysis of a prospective, single-center parallel 1:1 randomized trial (RIC-STEMI) was performed. This analysis included 448 STEMI patients previously randomized to either PPCI alone (PPCI group) (n = 217) or RIC as an adjuvant to PPCI (RIC + PPCI group) (n = 231). Moreover, the sample was divided according to the time of PPCI: night-morning (22 h-11h59min) (n = 216) or afternoon (12 h-21h59min) (n = 232) groups. The primary follow-up endpoint was a composite of cardiac death and hospitalization due to heart failure. There were no significant differences in the clinical characteristics and the follow-up outcomes between groups. The afternoon period (HR = 0.474; 95% CI 0.230-0.977; p = 0.043) and RIC (HR = 0.423; 95% CI 0.195-0.917; p = 0.029) were independent predictors of the primary follow-up endpoint. An univariate analysis showed a lower frequency of primary follow-up endpoint, just in the afternoon period (10.3%vs0.9%; p = 0.002), in the RIC + PPCI group. A multivariate analysis revealed that RIC was an independent predictor of the primary follow-up endpoint in the afternoon group (HR = 0.098; 95% CI 0.012-0.785; p = 0.029), but not in the night-morning group. In addition, the afternoon period was not an independent predictor of the primary follow-up endpoint when the multivariate analysis was performed in the PPCI group. In conclusion, this study showed an important cardioprotective effect of RIC, namely in the afternoon period, suggesting that the afternoon period enhances the cardioprotection induced by RIC.

The effect of off-hours hip surgery on patients' outcomes: a RECORD-compliant retrospective, propensity score-matched cohort study

BACKGROUND

Off-hours working may have negative impacts on the performance of clinicians, leading to possible adverse outcomes of patients. We aimed to explore the impact of off-hours hip surgery on early postoperative outcomes.

METHODS

All patients who underwent hip surgery between January 2015, and December 2020 in our hospital were evaluated in this retrospective cohort study. We measured in-hospital mortality, some postoperative complications, and some intraoperative prognostic indicators. Propensity score matching (PSM) was used to adjust for confounding baseline factors.

RESULTS

We identified 143 patients in the original cohort. After PSM, 266 patients in the on-hours group were matched with 105 similar patients in the off-hours group. Compared with the on-hours group, the off-hours group had more general anesthesia (81.0% vs. 62.4%; RR, 1.30; 95% CI, 1.14 to 1.48; P=0.001), higher amount of intraoperative CRBC (0 U [0-2] vs. 0 U [0-0]; P=0.032) and FFP transfusion (0 mL [0-150] vs. 0 mL [0-0]; P=0.005), higher dosage of intraoperative sufentanil (24.5±14.5 μg vs. 20.7±13.9 μg; P=0.020), higher incidence of postoperative renal dysfunction (13.3% vs. 6.4%; RR, 2.09; 95% CI, 1.07 to 4.08; P=0.029), hypotension (2.9% vs. 0%; P=0.022), and hypoxemia (3.8% vs. 0.4%; RR, 10.13; 95% CI, 1.15 to 89.61; P=0.024), and higher in-hospital mortality (2.9% vs. 0%; P=0.022).

CONCLUSIONS

Off-hours hip surgery was associated with adverse early postoperative prognosis, suggesting that more attention should be paid to off-hours hip surgery.