Identification of common mechanisms and biomarkers of atrial fibrillation and heart failure based on machine learning.

AIMS: Atrial fibrillation (AF) is the most common arrhythmia. Heart failure (HF) is a disease caused by heart dysfunction. The prevalence of AF and HF were progressively increasing over time. The co-existence of AF and HF presents a significant therapeutic challenge. In order to provide new ideas for the diagnosis of AF and HF, it is necessary to carry out biomarker related studies. METHODS AND RESULTS: The training set and validation set data of AF and HF patient samples were downloaded from the GEO database, 'limma' was used to compare the differences in gene expression levels between the disease group and the normal group to screen for differentially expressed genes (DEGs). Weighted correlation network analysis (WGCNA) identified the modules with the highest positive correlation with AF and HF. Functional enrichment and PPI network construction of key genes were carried out. Biomarkers were screened by machine learning. The infiltration of immune cells in AF and HF groups was evaluated by R-packet 'CIBERSORT'. The miRNA network was constructed and potential therapeutic agents for biomarker genes were predicted through the drugbank database. Through WGCNA analysis, it was found that the modules most positively correlated with AF and HF were MEturquoise (r = 0.21, P value = 0.09) and MEbrown (r = 0.62, P value = 8e-12), respectively. We screened 25 genes that were highly correlated with both AF and HF. Lasso regression analysis results showed 7 and 20 core genes in AF and HF groups, respectively. The top 20 important genes in AF and HF groups were obtained as core genes by RF model analysis. Four biomarkers were obtained after the intersection of core genes in four groups, namely, GLUL, NCF2, S100A12, and SRGN. The diagnostic efficacy of four genes in AF validation sets was good (AUC: GLUL 0.76, NCF2 0.64, S100A12 0.68, and SRGN 0.76), as well as in the HF validation set (AUC: GLUL 0.76, NCF2 0.84, S100A12 0.92, and SRGN 0.68). The highest correlation with neutrophils was observed for GLUL, NCF2, and S100A12, while SRGN exhibited the strongest correlation with T cells CD4 memory resting in the AF group. GLUL, NCF2, S100A12, and SRGN were most associated with neutrophils in the HF group. A total of 101 miRNAs were predicted by four genes, and GLUL, NCF2, and S100A12 predicted a total of 10 potential therapeutic agents. CONCLUSIONS: We identified four biological markers that are highly correlated with AF and HF, namely, GLUL, NCF2, S100A12, and SRGN. Our findings provide theoretical basis for the clinical diagnosis and treatment of AF and HF.

Cardioprotective effects of Schisantherin A against isoproterenol-induced acute myocardial infarction through amelioration of oxidative stress and inflammation via modulation of PI3K-AKT/Nrf2/ARE and TLR4/MAPK/NF-κB pathways in rats.

BACKGROUND AND AIMS: The scientific community is concerned about cardiovascular disease mortality and morbidity, especially myocardial infarction (MI). Schisantherin A (SCA), a dibenzocyclooctadiene lignan monomer found in S. chinensis fruits has cardiovascular advantages such as increasing NO production in isolated rat thoracic aorta and reducing heart damage caused by ischemia-reperfusion (I/R) through decreasing apoptosis. The present study was undertaken to explore the potential effects of SCA on ISO-induced myocardial infarction in rats. METHODS: Rats were randomly allocated to four groups: control; ISO-treated, and two additional groups of ISO + SCA (5 or 10 mg/kg body weight). All SCA-treated groups were administered with SCA for 20 days and all ISO groups were challenged with ISO on days 19 and 20. RESULTS: SCA significantly attenuated ISO-induced rise in heart/body weight ratio, myocardial infarct size, and cardiac functional biomarkers (CK-MB, cTnI and BNP). SCA pre- and co-treatment resulted in a significant reduction in oxidative stress (via MDA, NO and GSH and increased activities of SOD, CAT and GPx) and inflammation (via decreased levels of TNF-α, IL-6 and IL-1ß) markers when compared to the same levels in cardiac tissue of ISO-treated rats. This study also showed that SCA protects ISO-induced oxidative stress and inflammation by activating the PI3K-AKT/Nrf2/ARE pathway and suppressing TLR4/MAPK/NF-κB pathways. Furthermore, SCA treatment protected histopathological alterations observed in only ISO-treated cardiac transverse sections of rats. CONCLUSION: In conclusion, the findings of this study suggest that SCA protects against cardiac injury in the ISO-induced MI model of rats.

Prognostic value of circulating microRNA-21-5p and microRNA-126 in patients with acute myocardial infarction and infarct-related artery total occlusion.

Background: Cardiovascular disease, including acute myocardial infarction (AMI), is a major global cause of mortality and morbidity. Specificity and sensitivity limit the utility of classic diagnostic biomarkers for AMI. Therefore, it is critical to identify novel biomarkers for its accurate diagnosis. Cumulative studies have demonstrated that circulating microRNAs (miRs) participate in the pathophysiological processes of AMI and are promising diagnostic biomarkers for the condition. This study aimed to ascertain the diagnostic accuracy of circulating miR-21-5p and miR-126 used as biomarkers in patients with AMI and infarct-related artery total occlusion (IR-ATO) or infarct-related blood-vessel recanalization (IR-BVR). Methods: The expression of miR-21-5p and miR-126 was examined separately in 50 healthy subjects, 51 patients with IR-ATO AMI, and 49 patients with IR-BVR AMI using quantitative real-time polymerase chain reaction. Results: When compared with the control group, the IR-ATO AMI group exhibited increased miR-21-5p (p < 0.0001) and miR-126 (p < 0.0001), and the IR-BVR AMI group exhibited increased miR-21-5p (p < 0.0001). However, there was no significant difference in miR-126 between the IR-BVR AMI and the control groups. A Spearman's correlation coefficient showed a strong correlation was found between miR-21-5p, miR-126, cardiac troponin-I, and creatine kinase isoenzyme in all three groups, while a receiver operating characteristic analysis revealed that miR-21-5p and miR-126 exhibited considerable diagnostic accuracy for IR-ATO AMI. Conclusion: Circulating miR-21-5p and miR-126 may be promising prognostic biomarkers for patients with AMI and IR-ATO.

Direct oral anticoagulants versus vitamin K antagonists for patients with left ventricular thrombus.

BACKGROUND: A retrospective cohort study was conducted to compare the efficacy and safety of direct oral anticoagulants (DOACs) and vitamin K antagonists (VKAs) in the treatment of patients with left ventricular thrombus (LVT). METHODS: Consecutive patients admitted to our institution with LVT between February 2009 and December 2020 and treated with either DOACs or VKAs were considered for inclusion in this study. The outcomes included stroke or systemic embolism (SSE), thrombus resolution, and bleeding events. RESULTS: Eighty-seven patients with LVT were identified. Of these, 25 patients were treated with DOACs and 62 patients were treated with VKA. The average follow-up period was 2.37±2.1 years. DOACs were associated with similar incidences of stroke (4.0% vs. 4.8%; P=0.158), systemic embolism (0% vs. 1.6%; P=0.906), SSE (4.0% vs. 6.5%; P=0.657), thrombus resolution (76.0% vs. 74.2%; P=0.057), and blooding events (4.0% vs. 3.2%; P=0.858) as compared to VKAs. In the univariate logistic regression analysis, there was a significant difference between the DOAC and VKA groups in the incidence of SSE when antiplatelets were controlled [odds ratio (OR) =0.34, 95% confidence interval (CI): 0.21, 0.98; P=0.027]. However, in the multivariate analysis, antiplatelets had no significant effect on the outcome (OR =0.41, 95% CI: 0.36, 1.54; P=0.366). CONCLUSIONS: DOACs had similar efficacy and safety to VKAs in the treatment of patients with LVT. Randomized controlled trials should be conducted to verify our findings.

Dioscin attenuates lipopolysaccharide-induced inflammatory myocardial injury through oxidative stress-related pathway.

BACKGROUND: Lipopolysaccharide (LPS) is one of the main causes of myocardial injury. Dioscin has a protective effect on myocardial injury induced by LPS; however, the biological function and mechanism remain unclear. The purpose of this study was to investigate the effect of dioscin on myocardial injury induced by LPS. METHODS: The myocardial injury model was constructed through LPS treatment of primary rat cardiomyocytes. Cardiomyocytes were treated with different concentrations of dioscin (50, 100, and 200 ng/mL). MTT was used to detect the activity of cardiomyocytes; flow cytometry and TUNEL assay were used to detect apoptosis; and enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of inflammatory cytokines, tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6). The release of superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH) was detected according to the kit instructions. The levels of apoptosis-related proteins (Bax, caspase-3, and Bcl 2) and the Nrf2-Keap1 pathway proteins were detected by western blot. RESULTS: Dioscin significantly reduced LPS-induced cardiomyocyte injury in neonatal rats in a concentration- and time-dependent manner. Dioscin also significantly inhibited cardiomyocyte inflammation and apoptosis induced by LPS. With the increase of dioscin concentration, reactive oxygen species (ROS) and MDA were downregulated, and SOD and GSH were upregulated. Moreover, dioscin inhibited LPS-induced myocardial injury by inhibiting the Nrf2-Keap1 pathway. CONCLUSIONS: Our study suggests that dioscin attenuates LPS-induced myocardial injury through oxidative stress-related pathways.