Preoperative plasma biomarkers associated with atrial fibrillation after coronary artery bypass surgery

Lipid metabolism-associated metabolites on cardiovascular diseases: a two-sample Mendelian randomized study

Background

There is a growing body of evidence indicating that metabolites are associated with an increased risk of cardiovascular diseases (CVDs), the underlying causality of these associations remains largely unchallenged. Given the inherent difficulty in establishing causality using epidemiological data, we employed the technique of Mendelian randomization to investigate the potential role of plasma metabolite factors in influencing the risk of CVDs.

Methods

The exposure was based on 1,400 plasma metabolites, and outcomes involved four CVD datasets from public databases. Initial causality was assessed by inverse variance weighting (IVW), followed by sensitivity analyses using MR-Egger regression, weighted median, and Multiple Effectiveness Residual Sums and Outliers (MR-PRESSO) method. Potential heterogeneity and multivalence were assessed using the MR-Egger intercept and Cochran's Q statistic. After Bonferroni correction, causal associations were found to be significant with p-values less than 0.05. All statistical analyses were rigorously executed in R software.

Results

Our findings identified causal relationships between 15 metabolites and cardiovascular disease. Of these, 4 were associated with AA (aortic aneurysm), 7 with atrial fibrillation and flutter, 2 with HF (heart failure), and 3 with stroke.

Conclusion

This is the first systematic mendelian randomization analysis using genome-wide data to assess the causal relationship between serum metabolites and different cardiovascular diseases, providing preliminary evidence for the impact of lipid metabolism disorders on cardiovascular disease risk.

A Review on the Etiologies of the Development of Atrial Fibrillation After Cardiac Surgery

Postoperative atrial fibrillation (POAF) is the most common arrhythmia following cardiac surgery. This review critically explores the interplay between cardiopulmonary bypass (CPB) and aortic cross-clamping (ACC) times in POAF development. CPB disrupts systemic homeostasis by inducing inflammatory cascades, oxidative stress, and ischemia-reperfusion injury. Prolonged ACC times further exacerbate myocardial ischemia and structural remodeling, with durations exceeding 60-75 min consistently linked to an increased POAF risk. However, variability in outcomes across studies reveals the complex, multifactorial nature of POAF pathogenesis. Patient-specific variables, such as baseline comorbidities and myocardial protection strategies, modulate these risks, emphasizing the need for personalized surgical approaches. Despite advancements in myocardial protection techniques and anti-inflammatory strategies, the incidence of POAF remains persistently high, indicating a gap in translating mechanistic insights into effective interventions. Emerging biomarkers, including microRNAs (e.g., miR-21, miR-483-5p, etc.) and markers of myocardial injury like troponin I, offer potential for enhanced risk stratification and targeted prevention. However, their clinical applicability requires further validation in diverse patient populations. This review underscores the critical need for integrative research that combines clinical, molecular, and procedural variables to elucidate the nuanced interplay of factors driving POAF. Future directions include leveraging advanced intraoperative monitoring tools, refining thresholds for CPB and ACC times, and developing individualized perioperative protocols.

Lysine 2-hydroxyisobutyrylation of HXK1 alters energy metabolism and KATP channel function in the atrium from patients with atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) is the most common form of arrhythmia and is a growing clinical problem. Post-translational modifications (PTMs) constitute crucial epigenetic mechanisms but modification of lysine 2-hydroxyisobutyrylation (Khib) in AF is still unknown. This study aimed to investigate the role and mechanism of Khib in AF.

METHODS

PTM proteomics was applied in the human atrial tissue from AF and sinus rhythm patients with heart valve disease during cardiac surgery to identify the Khib sites. The functional changes of differential modification sites were further validated at the cellular level. Cellular electrophysiology was performed to record the ion channel current and action potential duration (APD).

RESULTS

The modification of 124 Khib sites in 35 proteins and 67 sites in 48 proteins exhibited significant increase or decrease in AF compared to sinus rhythm. Ten Khib sites were included in energy metabolism-related signaling pathways (HXK1, TPIS, PGM1, and ODPX in glycolysis; MDHC and IDH3A in tricarboxylic acid cycle; NDUS2, ETFB, ADT3, and ATPB in oxidative respiratory chain). Importantly, decreased HXK1 K418hib regulated by HDAC2 attenuated the original chemical binding domain between HXK1 and glucose, inhibited the binding ability between HXK1 and glucose, and reduced catalytic ability of the enzyme, resulting in low production of glucose-6-phosphate and ATP. Further, it also increased Kir6.2 protein and the current of KATP channel, and decreased APD.

CONCLUSIONS

This study demonstrates the importance of Khib to catalysis of HXK1 and reveals molecular mechanisms of HXK1 K418hib in AF, providing new insight into strategies of AF.

Pericardial Fluid Biomarkers as Early Predictors for Postoperative Atrial Fibrillation-A Systematic Review

(1) Background: Postoperative atrial fibrillation (POAF) is one of the most common complications of cardiac surgery, frequently occurring in the first 2-4 days after surgery. With a variable incidence depending on the type of surgery, research in recent years has focused on identifying predisposing factors with the aim of correcting them and thus decreasing the risk of cardiovascular and total morbidity and mortality. The analysis of pericardial fluid allowed the identification of biomarkers (interleukin-6, mitochondrial DNA, myeloperoxidase or natriuretic peptides) whose presence postoperatively was associated with increased risk of POAF. (2) Materials and Methods: We conducted a search on EMBASE and PubMed and identified 75 articles, of which 10 entered the final analysis. (3) Results: Patients who develop POAF accumulate large amounts of interleukin 6, mitochondrial DNA, myeloperoxidase, or secondary atrial natriuretic peptide as a consequence of the associated inflammatory status, atrial remodeling, or disturbance of homeostasis of various ions. There are also observations that their levels in the pericardium correlate with blood levels, but further studies on larger cohorts of patients are needed to provide new evidence in this regard. (4) Conclusions: Early recognition of patients at risk of developing POAF based on easy-to-dose and easy-to-use biochemical biomarkers, whose association with POAF has been demonstrated so far in small cohorts of patients, has both therapeutic and prognostic implications, which justifies further research on large cohorts of patients.

Metabolomics in Atrial Fibrillation: Unlocking Novel Biomarkers and Pathways for Diagnosis, Prognosis, and Personalized Treatment

BACKGROUND/OBJECTIVES

Atrial fibrillation (AF) is the most frequent arrhythmia in the adult population associated with a high rate of severe consequences leading to significant morbidity and mortality worldwide. Therefore, its prompt recognition is of high clinical importance. AF detection often remains challenging due to unspecific symptoms and a lack of reliable biomarkers for its prediction. Herein, novel bioanalytical methodologies, such as metabolomics, offer new opportunities for a better understanding of the underlying pathological mechanisms of cardiovascular diseases, including AF. The metabolome, considered a complete set of small molecules present in the organism, directly reflects the current phenotype of the studied system and is highly sensitive to any changes, including arrhythmia's onset. A growing body of evidence suggests that metabolite profiling has prognostic value in AF prediction, highlighting its potential role not only in early diagnosis but also in guiding therapeutic interventions. By identifying specific metabolites as a disease biomarker or recognising particular metabolomic pathways involved in the AF pathomechanisms, metabolomics could be of great clinical value for further clinical decision-making, risk stratification, and an individual personalised approach. The presented narrative review aims to summarise the current state of knowledge on metabolomics in AF with a special emphasis on its implications for clinical practice and personalised medicine.

Metabolomics in atrial fibrillation - A review and meta-analysis of blood, tissue and animal models

BACKGROUND

Atrial fibrillation (AF) is a highly prevalent cardiac arrhythmia associated with severe cardiovascular complications. AF presents a growing global challenge, however, current treatment strategies for AF do not address the underlying pathophysiology. To advance diagnosis and treatment of AF, a deeper understanding of AF root causes is needed. Metabolomics is a fast approach to identify, quantify and analyze metabolites in a given sample, such as human serum or atrial tissue. In the past two decades, metabolomics have enabled research on metabolite biomarkers to predict AF, metabolic features of AF, and testing metabolic mechanisms of AF in animal models. Due to the field's rapid evolution, the methods of AF metabolomics studies have not always been optimal. Metabolomics research has lacked standardization and requires expertise to face methodological challenges.

PURPOSE OF THE REVIEW

We summarize and meta-analyze metabolomics research on AF in human plasma and serum, atrial tissue, and animal models. We present the current progress on metabolic biomarkers candidates, metabolic features of clinical AF, and the translation of metabolomics findings from animal to human. We additionally discuss strengths and weaknesses of the metabolomics method and highlight opportunities for future AF metabolomics research.

Risk Factors of Postoperative Atrial Fibrillation After Isolated Coronary Artery Bypass Grafting Surgery in the Recent 10 Years: Clinical Analysis of 6229 Patients

BACKGROUND

Postoperative atrial fibrillation (POAF) is a common complication after coronary artery bypass grafting (CABG) that prolongs hospitalization and increases expenses.

HYPOTHESIS

Perioperative risk factors may predict POAF.

METHODS

From March 2015 to January 2023, 6229 patients who underwent isolated CABG and were in sinus rhythm before CABG were included in this retrospective study. The preoperative and postoperative variants of patients were collected and analyzed by univariate analyses between the patients with and without POAF. Multivariate logistic regression analysis was then used to study the independent risk factors for POAF.

RESULTS

The incidence of POAF in this group of patients was 30.94%. Univariate analyses demonstrated that age (p < 0.001), hypertension (p < 0.001), smoking (p < 0.05), cardiopulmonary bypass (CPB) time (p < 0.01), and ejection fraction (EF, p < 0.01) were the risk factors for POAF. Multivariate logistic regression analysis determined the independent risk factors associated with POAF were old age (odds ratio [OR] = 1.062, p = 0.000) and low EF (OR = 0.980; p = 0.008).

CONCLUSIONS

In the current era, after isolated CABG surgery, there is still a quite high incidence of POAF (30.94% in this group of CABG patients). The main risk factors correlating to POAF include age, hypertension, smoking, CPB time, and EF. Among these factors, multivariate analysis identified old age and low EF as the independent risk factors associated with POAF. Particular care should be taken in the perioperative period for these patients in the prevention of POAF.

Differential Expression of mRNA in Peripheral Blood Mononuclear Cells May Predict Postoperative Atrial Fibrillation in Coronary Artery Bypass Surgery Patients

Postoperative Atrial Fibrillation (POAF) frequently follows Coronary Artery Bypass Grafting (CABG) surgery. This prospective study investigates genes linked to POAF in CABG patients, aiming to create a predictive model. Employing differential gene and methylation analyses, the study identified four genes (WARS2, CKAP2, CHI3L1, HSD17B6) associated with POAF. Preoperative plasma samples and clinical data were collected from 139 CABG patients, categorized into POAF (+) (43) and POAF (-) (96). Real-time quantitative PCR assessed gene expression, and a predictive model using the LASSO method demonstrated robust performance, with AUC values of 0.8895 in the training set and 0.7840 in the test set. This pioneering study integrates genomics and clinical data, suggesting WARS2, CKAP2, and CHI3L1 as potential indicators for POAF prediction.

Postoperative QRS duration to left ventricular end-diastolic diameter ratio as a predictor for the risk of postoperative atrial fibrillation in cardiac surgery: A single-center prospective study

BACKGROUND AND AIMS

Postoperative atrial fibrillation (POAF) is a frequent complication following cardiac surgery and is associated with adverse clinical outcomes. Our study aimed at determining the clinical and echocardiographic predictors of POAF in patients with cardiac surgery and management of this group of patients may improve their outcome.

METHODS

We prospectively enrolled patients from the department of cardiovascular surgery in the Second Hospital of Tianjin Medical University from October 23, 2020 to October 30, 2022, without a history of atrial fibrillation. Cox regression was used to identify significant predictors of POAF.

RESULTS

A total of 217 patients (79 [36.41 %] were female, 63.96 ± 12.32 years) were included. 88 (40.55 %) patients met the criteria for POAF. Cox regression showed that preoperative left atrial diameter (LAD) (HR: 1.040, 95 % CI 1.008-1.073, p = 0.013) and postoperative QRS/LVEDD (HR: 0.398, 95 % CI 0.193-0.824, p = 0.013) and E/e' (HR: 1.029, 95 % CI 1.002-1.057，p = 0.033) were predictors of POAF.

CONCLUSION

Preoperative LAD and postoperative QRS/LVEDD and E/e' were predictors of POAF in patients undergoing cardiac surgery.

TRIAL REGISTRATION SITE

http://www.chictr.org.cn.

REGISTRATION NUMBER

ChiCTR2200063344.

Insights into the Role of Glutathione Peroxidase 3 in Non-Neoplastic Diseases

Reactive oxygen species (ROSs) are byproducts of normal cellular metabolism and play pivotal roles in various physiological processes. Disruptions in the balance between ROS levels and the body's antioxidant defenses can lead to the development of numerous diseases. Glutathione peroxidase 3 (GPX3), a key component of the body's antioxidant system, is an oxidoreductase enzyme. GPX3 mitigates oxidative damage by catalyzing the conversion of hydrogen peroxide into water. Beyond its antioxidant function, GPX3 is vital in regulating metabolism, modulating cell growth, inducing apoptosis and facilitating signal transduction. It also serves as a significant tumor suppressor in various cancers. Recent studies have revealed aberrant expression of GPX3 in several non-neoplastic diseases, associating it with multiple pathological processes. This review synthesizes the current understanding of GPX3 expression and regulation, highlighting its extensive roles in noncancerous diseases. Additionally, this paper evaluates the potential of GPX3 as a diagnostic biomarker and explores emerging therapeutic strategies targeting this enzyme, offering potential avenues for future clinical treatment of non-neoplastic conditions.

Metabolomics Analysis Identifies Differential Metabolites as Biomarkers for Acute Myocardial Infarction

Myocardial infarction (MI), including ST-segment elevation MI (STEMI) and non-ST-segment elevation MI (NSTEMI), is still a leading cause of death worldwide. Metabolomics technology was used to explore differential metabolites (DMs) as potential biomarkers for early diagnosis of STEMI and NSTEMI. In the study, 2531 metabolites, including 1925 DMs, were discovered. In the selected 27 DMs, 14 were successfully verified in a new cohort, and the AUC values were all above 0.8. There were 10 in STEMI group, namely L-aspartic acid, L-acetylcarnitine, acetylglycine, decanoylcarnitine, hydroxyphenyllactic acid, ferulic acid, itaconic acid, lauroylcarnitine, myristoylcarnitine, and cis-4-hydroxy-D-proline, and 5 in NSTEMI group, namely L-aspartic acid, arachidonic acid, palmitoleic acid, D-aspartic acid, and palmitelaidic acid. These 14 DMs may be developed as biomarkers for the early diagnosis of MI with high sensitivity and specificity. These findings have particularly important clinical significance for NSTEMI patients because these patients have no typical ECG changes.

Metabolomics and Biomarkers for Paroxysmal and Persistent Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF) is the most common type of arrhythmia worldwide and is associated with serious complications. This study investigated the metabolic biomarkers associated with AF and the differences in metabolomics and associated metabolic biomarkers between paroxysmal AF (AFPA) and persistent AF.

METHODS AND RESULTS

Plasma samples were prospectively collected from patients with AF and patients in sinus rhythm with negative coronary angiography. The patients were divided into 3 groups: AFPA, persistent AF, and sinus rhythm (N=54). Metabolomics (n=36) using ultra-high-performance liquid chromatography mass spectrometry was used to detect differential metabolites that were validated in a new cohort (n=18). The validated metabolites from the validation phase were further analyzed by receiver operating characteristic. Among the 36 differential metabolites detected by omics assay, 4 were successfully validated with area under the curve >0.8 (P<0.05). Bioinformatics analysis confirmed the enrichment pathways of unsaturated fatty acid biosynthesis, glyoxylate and dicarboxylate metabolism, and carbon metabolism. Arachidonic acid was a potential biomarker of AFPA, glycolic acid and L-serine were biomarkers of AFPA and persistent AF, and palmitelaidic acid was a biomarker of AFPA.

CONCLUSIONS

In this metabolomics study, we detected 36 differential metabolites in AF, and 4 were validated with high sensitivity and specificity. These differential metabolites are potential biomarkers for diagnosis and monitoring of disease course. This study therefore provides new insights into the precision diagnosis and management of AF.

Efficacy of electroacupuncture in improving postoperative ileus in patients receiving colorectal surgery: a systematic review and meta-analysis

BACKGROUND

This meta-analysis aimed to evaluate the efficacy and safety of electroacupuncture (EA) in improving postoperative ileus after colorectal surgery.

METHODS

Electronic databases (e.g. Medline) were screened to identify randomized controlled trials that focused on the association between EA and postoperative ileus. Time to first flatus served as the primary outcome, while the secondary outcomes included time required for the recovery of other gastrointestinal functions (e.g. bowel sound recovery), time to tolerability of liquid/solid food, postoperative pain scores, risk of overall complications, and hospital length of stay.

RESULTS

Our meta-analysis focusing on 16 studies with a total of 1562 patients demonstrated positive associations of EA with shorter times to the first flatus [mean difference (MD): -10.1 h, P <0.00001, n =1562], first defecation (MD: -11.77 h, P <0.00001, n =1231), bowel sound recovery (MD: -10.76 h, P <0.00001, n =670), tolerability of liquid (MD: -16.44 h, P =0.0002, n =243), and solid food (MD: -17.21 h, P =0.005, n =582) than those who received standard care. The use of EA was also correlated with a lower risk of overall complications (risk ratio:0.71, P =0.04, n =1011), shorter hospital length of stay (MD: -1.22 days, P =0.0001, n =988), and a lower pain score on postoperative days two (standardized MD: -0.87, P =0.009, n =665) and three (standardized MD: -0.45, P <0.00001, n =795), without a difference in time to first ambulation.

CONCLUSION

Our findings showed an association between EA and enhanced gastrointestinal functional recovery and reduced pain severity following colorectal surgery, highlighting the potential benefits of incorporating EA into perioperative care to enhance recovery outcomes in this setting.

Soluble TREM-1 plasma levels are associated with acute kidney injury, acute atrial fibrillation and prolonged ICU stay after cardiac surgery- a proof-concept study

Background

Cardiopulmonary bypass (CPB) during cardiac surgery leads to deleterious systemic inflammation. We hypothesized that TREM-1, a myeloid receptor shed after activation, drives systemic inflammation during CPB.

Methods

Prospective observational bi-centric study. Blood analysis (flow cytometry and ELISA) before and at H2 and H24 after CPB. Inclusion of adult patients who underwent elective cardiac surgery with CPB.

Results

TREM-1 expression on neutrophils decreased between H0 and H2 while soluble (s)TREM-1 plasma levels increased. sTREM-1 levels increased at H2 and at H24 (p < 0.001). IL-6, IL-8, G-CSF and TNF-α, but not IL-1β, significantly increased at H2 compared to H0 (p < 0.001), but dropped at H24. Principal component analysis showed a close relationship between sTREM-1 and IL-8. Three patterns of patients were identified: Profile 1 with high baseline sTREM-1 levels and high increase and profile 2/3 with low/moderate baseline sTREM-1 levels and no/moderate increase overtime. Profile 1 patients developed more severe organ failure after CPB, with higher norepinephrine dose, higher SOFA score and more frequently acute kidney injury at both H24 and H48. Acute atrial fibrillation was also more frequent in profile 1 patients at H24 (80% vs. 19.4%, p = 0.001). After adjustment on age and duration of CPB, H0, H2 and H24 sTREM-1 levels remained associated with prolonged ICU and hospital length of stay.

Conclusions

Baseline sTREM-1 levels as well as early kinetics after cardiac surgery identified patients at high risk of post-operative complications and prolonged length of stay.

Metabolic signatures in pericardial fluid and serum are associated with new-onset atrial fibrillation after isolated coronary artery bypass grafting

Postoperative atrial fibrillation (POAF) is a common complication of coronary artery bypass grafting (CABG) procedures. However, the molecular mechanism of POAF remains poorly understood, hence the absence of effective prevention strategies. Here we used targeted metabolomics on pericardial fluid and serum samples from CABG patients to investigate POAF-associated metabolic alterations and related risk prediction of new-onset AF. Nine differential metabolites in various metabolic pathways were found in both pericardial fluid and serum samples from patients with POAF and without POAF. By using machine learning algorithms and regression models, a 4-metabolite (aceglutamide, ornithine, methionine, and arginine) risk prediction model was constructed and showed accurate performance in predicting POAF in both discovery and validation sets. This work extends the metabolic insights of the cardiac microenvironment and blood in patients with POAF and paves the way for the use of targeted metabolomics for predicting POAF in patients with CABG surgery.

Myeloperoxidase Levels in Pericardial Fluid Is Independently Associated with Postoperative Atrial Fibrillation after Isolated Coronary Artery Bypass Surgery

BACKGROUND

Postoperative atrial fibrillation (POAF) is the most common complication after surgery for atherosclerotic cardiovascular disease (ASCVD) and leads to extended hospital stays and increased mortality. Myeloperoxidase (MPO) in postoperative pericardial drainage fluid is associated with an increased risk of POAF; however, the correlations between MPO in intraoperative pericardial fluid and POAF remain largely unknown. The aim of the study was to evaluate whether MPO is associated with POAF.

METHODS

A total of 97 patients with no history of atrial arrhythmia who had undergone coronary artery bypass surgery (CABG) were identified. We prospectively measured the levels of MPO in intraoperative pericardial fluid and blood using the human magnetic Luminex assay. Then, the occurrence of atrial fibrillation was continuously observed by postoperative ECG and telemetry strips until discharge.

RESULTS

Our data showed that POAF occurred in 24 of 97 patients (24.74%). MPO levels in blood were higher in the POAF group than the SR group (p = 0.064). Patients with POAF had significantly higher intraoperative pericardial fluid MPO levels than patients who remained in SR (p = 0.021). There was no significant correlation between pericardial fluid MPO levels and blood MPO levels (r = -0.47, p = 0.770). In a multivariable logistic regression model, pericardial fluid MPO levels were significantly associated with a higher risk of POAF (odds ratio = 1.016, 95% confidence interval, 1.001-1.031; p = 0.031).

CONCLUSIONS

Higher intraoperative pericardial fluid MPO levels are linked with POAF in patients undergoing CABG. This finding provides insight into a possible mechanism of MPO in pericardial fluid increase susceptibility to developing POAF in patients undergoing CABG.

Predictive Capability of Metabolic Panels for Postoperative Atrial Fibrillation in Cardiac Surgery Patients

INTRODUCTION

Postoperative atrial fibrillation (POAF) occurs in up to 65% of cardiac surgery patients and is associated with an increased risk for stroke and mortality. Electrolyte disturbances in sodium (Na+), potassium (K+), total calcium (Ca2+), chloride (Cl-), and magnesium (Mg2+) are predisposing factors for POAF, but these imbalances are yet to be used to predict POAF. The purpose of this study is to determine whether the development of POAF can be predicted by blood plasma ionic composition.

METHODS

Metabolic panels of patients with no prior history of atrial fibrillation who did (n = 763) and did not develop POAF (n = 2144) after cardiac surgery were obtained from the Carilion Clinic electronic medical record system. We initially evaluated serum Na+, K+, Ca2+, Cl-, and Mg2+ in the two groups using descriptive statistics via scatter and spaghetti plots and then with predictive modeling via logistic regression and random forest models.

RESULTS

Neither scatter nor spaghetti plots of electrolyte data revealed a significant difference between those who did and did not develop POAF. Two logistic regression models and two random forest models with POAF status as the outcome were generated using the first observation for each electrolyte and the coefficient of the linear regression, which was obtained from a linear fit of the scatter plot. The random forest model using the first observation had a sensitivity of only 12.2%, but all four models had specificities more than 97%.

CONCLUSIONS

Neither of the two logistic regression nor two random forest models were able to effectively predict the development of POAF from plasma ionic concentrations, but the random forest models effectively classified patients who would not develop POAF.

Molecular Signatures of Human Chronic Atrial Fibrillation in Primary Mitral Regurgitation

Objectives

Transcriptomics of atrial fibrillation (AFib) in the setting of chronic primary mitral regurgitation (MR) remains to be characterized. We aimed to compare the gene expression profiles of patients with degenerative MR in AFib and sinus rhythm (SR) for a clearer picture of AFib pathophysiology.

Methods

After transcriptomic analysis and bioinformatics (n = 59), differentially expressed genes were defined using 1.5-fold change as the threshold. Additionally, independent datasets from GEO were included as meta-analyses.

Results

QRT-PCR analysis confirmed that AFib persistence was associated with increased expression molecular changes underlying a transition to heart failure (NPPB, P = 0.002; ANGPTL2, P = 0.002; IGFBP2, P = 0.010), structural remodeling including changes in the extracellular matrix and cellular stress response (COLQ, P = 0.003; COMP, P = 0.028; DHRS9, P = 0.038; CHGB, P = 0.038), and cellular stress response (DNAJA4, P = 0.038). Furthermore, AFib persistence was associated with decreased expression of the targets of structural remodeling (BMP7, P = 0.021) and electrical remodeling (CACNB2, P = 0.035; MCOLN3, P = 0.035) in both left and right atrial samples. The transmission electron microscopic analysis confirmed ultrastructural atrial remodeling and autophagy in human AFib atrial samples.

Conclusions

Atrial cardiomyocyte remodeling in persistent AFib is closely linked to alterations in gene expression profiles compared to SR in patients with primary MR. Study findings may lead to novel therapeutic targets. This trial is registered with ClinicalTrials.gov identifier: NCT00970034.

Biochemical predictors of postoperative atrial fibrillation following cardiac surgery

Background

New-onset postoperative atrial fibrillation (POAF) is common after cardiac surgery. Early identification of its risk factors during the preoperative period would help in reducing the associated morbidity, mortality, and healthcare costs.

Aim of the study

This study aimed to identify the predictors of POAF following open cardiac surgery, with emphasis on biochemical parameters.

Methods

A total of 1191 patients with no preoperative atrial fibrillation (AF) and undergoing open cardiac surgery for any reason were included in this retrospective study. Data on clinical and biochemical parameters, the occurrence of new-onset AF, and its clinical course were retrieved from the hospital database.

Results

During the early postoperative period 330 patients (27.7%) developed atrial fibrillation, at median third postoperative day (range 1–6 days) and 217 (65.8%) responded to treatment. Multivariate analysis identified the following as the significant independent predictors of any POAF: EF < 60% (Odds ratio (OR), 2.6), valvular intervention (OR, 2.4), liver failure (OR, 2.4), diabetes (OR, 1.6), low hematocrit (OR, 2.1), low thrombocyte (OR, 5.6), low LDL (OR, 1.6), high direct bilirubin (OR, 2.0), low GFR (OR, 1.6), and high CRP (OR, 2.0). Following parameters emerged as significant independent predictors of persistent AF: EF < 60% (OR, 1.9), diabetes (OR, 2.1), COPD (OR, 1.8), previous cardiac surgery (OR, 3.1), valvular intervention (OR, 2.4), low hematocrit (OR, 1.9), low LDL (OR, 2.1), high HbA1c (OR, 2.0), and high CRP (OR, 2.7).

Conclusions

Certain parameters assessed during preoperative physical and laboratory examinations have the potential to be used as markers of POAF.

Biomarkers and key pathways in atrial fibrillation associated with mitral valve disease identified by multi-omics study

Background

Mitral valve disease (MVD)-associated atrial fibrillation (AF) is one of the most common arrhythmias with an increased risk of thromboembolic events. This study aimed to identify the molecular mechanisms and possible biomarkers for chronic AF in MVD by using multi-omics methods.

Methods

This prospective study enrolled patients with MVD (n=100) undergoing mitral valve replacement surgery. The patients were allocated into chronic AF and sinus rhythm (SR) groups. Plasma samples were collected preoperatively. Proteomics was performed with isobaric tags for relative and absolute quantitation (iTRAQ) to identify differential proteins (DPs) between the two groups. The selected DPs were then validated in a new cohort of patients by enzyme-linked immunosorbent assay (ELISA). A gas chromatography-mass spectrometer was used in the metabolomics study to identify differential metabolites (DMs). Bioinformatics analyses were performed to analyze the results.

Results

Among the 447 plasma proteins and 322 metabolites detected, 57 proteins and 55 metabolites, including apolipoprotein A-I (ApoA-I), apolipoprotein A-II (ApoA-II), LIM domain only protein 7 (LMO7), and vitronectin (VN) were differentially expressed between AF and SR patients. Bioinformatics analyses identified enriched pathways related to AF, including peroxisome proliferator-activated receptor alpha (PPARα), the renin angiotensin aldosterone system (RAAS), galactose, biosynthesis of unsaturated fatty acids, and linoleic acid metabolism.

Conclusions

Using integrated multi-omics technologies in MVD-associated AF patients, the present study, for the first time, revealed important signaling pathways, such as PPARα, as well as possible roles of other signaling pathways, including the RAAS and galactose metabolism to understand the molecular mechanism of MVD-associated AF. It also identified a large number of DPs and DMs. Some identified proteins and metabolites, such as ApoA-I, ApoA-II, LMO7, and VN, may be further developed as biomarkers for MVD-associated AF.