Associations of 50 modifiable risk factors with atrial fibrillation using Mendelian randomization analysis.

BACKGROUND: Substantial focus has been placed on atrial fibrillation (AF) treatment and associated stroke prevention rather than preventing AF itself. We employed Mendelian randomization (MR) approach to examine the causal relationships between 50 modifiable risk factors (RFs) and AF. METHODS: Instrumental variables for genetically predicted exposures were derived from corresponding genome-wide association studies (GWASs). Summary-level statistical data for AF were obtained from a GWAS meta-analysis (discovery dataset, N = 1,030,836) and FinnGen (validation dataset, N = 208,594). Univariable and multivariable MR analyses were performed, primarily using inverse variance weighted method with a series of robust sensitivity analyses. RESULTS: Genetic predisposition to insomnia, daytime naps, apnea, smoking initiation, moderate to vigorous physical activity and obesity traits, including body mass index, waist-hip ratio, central and peripheral fat/fat-free mass, exhibited significant associations with an increased risk of AF. Coffee consumption and ApoB had suggestive increased risks. Hypertension (odds ratio (OR) 95% confidence interval (CI): 5.26 (4.42, 6.24)), heart failure (HF) (OR 95% CI, 4.77 (2.43, 9.37)) and coronary artery disease (CAD) (OR 95% CI: 1.20 (1.16, 1.24)) were strongly associated with AF, while college degree, higher education attachment and HDL levels were associated with a decreased AF risk. Reverse MR found a bidirectional relationship between genetically predicted AF and CAD, HF and ischemic stroke. Multivariable analysis further indicated that obesity-related traits, systolic blood pressure and lower HDL levels independently contributed to the development of AF. CONCLUSIONS: This study identified several lifestyles and cardiometabolic factors that might be causally related to AF, underscoring the importance of a holistic approach to AF management and prevention.

Association between Hematocrit and Acute Kidney Injury in Patients with Acute Myocardial Infarction.

Backgrounds: Hematocrit is found an independent risk factor for acute kidney injury (AKI) in certain patients, but this effect in patients with acute myocardial infarction (AMI) is unclear. We aim to identify the relationship between hematocrit and AKI in patients with AMI. Methods: The patient data for the discovery and validation cohorts were extracted from the electronic Intensive Care Unit database and the Medical Information Mart for Intensive Care III database, respectively, to identify the relationship between hematocrit and AKI. With normal hematocrit as the reference, patients were divided into five groups based on the initial hematocrit value. The primary outcome was AKI during hospitalization. A multivariable logistic regression and a marginal effect analysis were used to evaluate the relationship between hematocrit and AKI. Results: In this study, a total of 9692 patients diagnosed with AMI were included, with 7712 patients in the discovery cohort and 1980 patients in the validation cohort. In the discovery cohort, hematocrit in 30-33%, 27-30% or < 27% were independent risk factors for AKI in the multivariate logistic analysis, with odds ratio (OR) of 1.774 (95% confidence interval [CI]: 1.203-2.617, p = 0.004), 1.834 (95% CI: 1.136-2.961, p = 0.013) and 2.577 (95% CI: 1.510-4.397, p < 0.001), respectively. Additionally, in the validation cohort, low hematocrit levels independently contributed to an increased risk of AKI among patients with AMI. During the analysis of marginal effects, a significant negative linear relationship between hematocrit levels and AKI was observed. Conclusions: Decreased hematocrit was an independent risk factor for AKI in patients with AMI. The relationship between hematocrit and AKI was negative linear.

Sex Differences in the Epidemiology, Risk Factors, and Prognosis of Malignant Ventricular Arrhythmias in Sepsis Patients.

Background: Women are frequently underrepresented in clinical trials and databases focusing on ventricular arrhythmias (VAs). However, understanding sex-based differences in risk factors and the prognosis of VAs is essential for tailoring personalized prevention and treatment strategies. This study aimed to investigate sex differences in the epidemiology, risk factors, and prognosis of VAs in patients with sepsis. Methods: We conducted a comprehensive analysis of 27,139 sepsis patients (mean [SD] age, 66.6 [16.2] years; 15,626 [57.6%] male), among whom 1136 (4.2%) developed VAs during their hospitalization. We evaluated VAs incidence and potential risk elements in both male and female patients, along with in-hospital mortality. Results: Men had a significantly higher likelihood of developing VAs compared to women (odds ratio [OR]: 1.70, 95% confidence interval [CI]: 1.50-1.94, p < 0.001). In the case of non-ischemic cardiomyopathy (NICM), the association with VAs was stronger in men than in women (relative risk ratio [RRR] = 1.63, 95% CI: 1.10-2.40, interaction p = 0.014). Furthermore, we observed significant sex-specific interactions in the relationship between incident VAs, congestive heart failure (CHF) (RRR = 1.35, 95% CI: 1.03-1.76, interaction p = 0.031), and pneumonia (RRR = 1.33, 95% CI: 1.02-1.74, interaction p = 0.036) when considering the adjusted model. The presence of VAs was associated with a nearly twofold increase in the risk of in-hospital mortality, a result that was observed in both sexes. Conclusions: In sepsis patients, the emergence of VAs independently escalates the risk of in-hospital mortality, with a notable correlation between male sex and an increased VAs risk. The impacts of CHF, NICM and pneumonia on incident VAs were significantly influenced by sex.

Association of stress hyperglycemia ratio and mortality in patients with sepsis: results from 13,199 patients.

BACKGROUND: The stress hyperglycemia ratio (SHR), adjusted for average glycemic status, is suggested for assessing actual blood glucose levels. Its link with adverse outcomes is known in certain populations, yet its impact on sepsis patients' prognosis is unclear. This study explores the association between SHR and mortality in sepsis. METHODS: We included 13,199 sepsis patients in this study and categorized SHR into distinct groups. Additionally, we utilized restricted cubic spline analysis to evaluate the correlation between SHR as a continuous variable and mortality. The primary outcome was 1-year all-cause mortality. Logistic regression and Cox proportional hazards models were employed to assess the associations between the SHR and both in-hospital mortality and 1-year mortality, respectively. RESULTS: Among the study participants, 4,690 (35.5%) patients died during the 1-year follow-up. After adjusting for confounding variables, we identified a U-shaped correlation between SHR and 1-year mortality. Using an SHR of 0.99 as the reference point, the hazard ratio for predicted 1-year mortality increased by 1.17 (95% CI 1.08 to 1.27) per standard deviation above 0.99, whereas each standard deviation increase predicted the hazard ratio of 0.52 (95% CI 0.39 to 0.69) below 0.99. Furthermore, we found that SHR could enhance the predictive performance of conventional severity scores. CONCLUSION: There exists a U shaped association between SHR and mortality in sepsis patients, where both low and high SHR values are associated with an increased risk of poor outcomes.

Catheter ablation of ventricular tachycardia in patients with arrhythmogenic right ventricular cardiomyopathy and biventricular involvement.

AIMS: Catheter ablation of ventricular tachycardia (VT) improves VT-free survival in 'classic' arrhythmogenic right ventricular cardiomyopathy (ARVC). This study aims to investigate electrophysiological features and ablation outcomes in patients with ARVC and biventricular (BiV) involvement. METHODS AND RESULTS: We assembled a retrospective cohort of definite ARVC cases with sustained VTs. Patients were divided into the BiV (BiV involvement) group and the right ventricular (RV) (isolated RV involvement) group based on the left ventricular systolic function detected by cardiac magnetic resonance. All patients underwent electrophysiological mapping and VT ablation. Acute complete success was non-inducibility of any sustained VT, and the primary endpoint was VT recurrence. Ninety-eight patients (36 ± 14 years; 87% male) were enrolled, including 50 in the BiV group and 48 in the RV group. Biventricular involvement was associated with faster clinical VTs, a higher VT inducibility, and more extensive arrhythmogenic substrates (all P < 0.05). Left-sided VTs were observed in 20% of the BiV group cases and correlated with significantly reduced left ventricular systolic function. Catheter ablation achieved similar acute efficacy between these two groups, whereas the presence of left-sided VTs increased acute ablation failure (40 vs. 5%, P = 0.012). Over 51 ± 34 months [median, 48 (22-83) months] of follow-up, cumulative VT-free survival was 52% in the BiV group and 58% in the RV group (P = 0.353). A multivariate analysis showed that younger age, lower RV ejection fraction (RVEF), and non-acute complete ablation success were associated with VT recurrence in the BiV group. CONCLUSION: Biventricular involvement implied a worse arrhythmic phenotype and increased the risk of left-sided VTs, while catheter ablation maintained its efficacy for VT control in this population. Younger age, lower RVEF, and non-acute complete success predicted VT recurrence after ablation.

Prognostic significance of the stress hyperglycemia ratio in critically ill patients.

BACKGROUND: The stress hyperglycemia ratio (SHR) has demonstrated a noteworthy association with unfavorable cardiovascular clinical outcomes and heightened in-hospital mortality. Nonetheless, this relationship in critically ill patients remains uncertain. This study aims to elucidate the correlation between SHR and patient prognosis within the critical care setting. METHODS: A total of 8978 patients admitted in intensive care unit (ICU) were included in this study. We categorized SHR into uniform groups and assessed its relationship with mortality using logistic or Cox regression analysis. Additionally, we employed the restricted cubic spline (RCS) analysis method to further evaluate the correlation between SHR as a continuous variable and mortality. The outcomes of interest in this study were in-hospital and 1-year all-cause mortality. RESULTS: In this investigation, a total of 825 (9.2%) patients experienced in-hospital mortality, while 3,130 (34.9%) individuals died within the 1-year follow-up period. After adjusting for confounding variables, we identified a U-shaped correlation between SHR and both in-hospital and 1-year mortality. Specifically, within the SHR range of 0.75-0.99, the incidence of adverse events was minimized. For each 0.25 increase in the SHR level within this range, the risk of in-hospital mortality rose by 1.34-fold (odds ratio [OR]: 1.34, 95% CI: 1.25-1.44), while a 0.25 decrease in SHR within 0.75-0.99 range increased risk by 1.38-fold (OR: 1.38, 95% CI: 1.10-1.75). CONCLUSION: There was a U-shaped association between SHR and short- and long-term mortality in critical ill patients, and the inflection point of SHR for poor prognosis was identified at an SHR value of 0.96.

Prognostic value of high-sensitivity C-reactive protein in patients undergoing percutaneous coronary intervention with different glycemic metabolism status.

BACKGROUND: High-sensitivity C-reaction protein (hsCRP), a biomarker of residual inflammatory risk, has been demonstrated with poor cardiovascular outcomes. We aimed to investigate the prognostic value of hsCRP in patients undergoing percutaneous coronary intervention (PCI) with or without diabetes mellitus (DM). METHODS: In this large-scale, prospective cohort study, we enrolled 8050 consecutive patients who underwent PCI for coronary artery stenosis. All subjects were stratified as high hsCRP (> 3 mg/L) and low hsCRP (≤ 3 mg/L) and were divided into four groups (hsCRP-L/non-DM, hsCRP-H/non-DM, hsCRP-L/DM, hsCRP-H/DM). The primary endpoint of the study was major adverse cardiovascular events (MACEs), including all-cause mortality, myocardial infarction, stroke, and unplanned vessel revascularization, evaluated at a 3 year follow-up. RESULTS: After 35.7 months (interquartile range: 33.2 to 36.0 months) of median follow-up time, 674 patients suffered from MACEs. We found elevated hsCRP was highly associated with an increased risk of MACEs in both diabetic (hazard ratio [HR] = 1.68, 95% confidence interval CI 1.29-2.19, P < 0.001) and non-diabetic patients (HR = 1.31, 95% CI: 1.05-1.62, P = 0.007) after adjustment for other confounding factors. Kaplan-Meier survival analysis showed the highest incidence of MACEs in hsCRP-H/DM (P < 0.001). In addition, the results of the restricted cubic spline analysis suggested a positive linear relationship between hsCRP and MACEs. CONCLUSION: Elevated hsCRP is an independent risk factors of MACEs in patients undergoing PCI irrespective of glycemic metabolism status.

Outcomes of catheter ablation in high-risk patients with Brugada syndrome refusing an implantable cardioverter defibrillator implantation.

AIMS: The aim of this study was to investigate the outcomes of catheter ablation (CA) in preventing arrhythmic events among patients with symptomatic Brugada syndrome (BrS) who declined implantable cardioverter defibrillator (ICD) implantation. METHODS AND RESULTS: A total of 40 patients with symptomatic BrS were included in the study, of which 18 refused ICD implantation and underwent CA, while 22 patients received ICD implantation. The study employed substrate modification (including endocardial and epicardial approaches) and ventricular fibrillation (VF)-triggering pre-mature ventricular contraction (PVC) ablation strategies. The primary outcomes were a composite endpoint consisting of episodes of VF and sudden cardiac death during the follow-up period. The study population had a mean age of 43.8 ± 9.6 years, with 36 (90.0%) of them being male. All patients exhibited the typical Type 1 BrS electrocardiogram pattern, and 16 (40.0%) were carriers of an SCN5A mutation. The Shanghai risk scores were comparable between the CA and the ICD groups (7.05 ± 0.80 vs. 6.71 ± 0.86, P = 0.351). Ventricular fibrillation-triggering PVCs were ablated in 3 patients (16.7%), while VF substrates were ablated in 15 patients (83.3%). Epicardial ablation was performed in 12 patients (66.7%). During a median follow-up of 46.2 (17.5-73.7) months, the primary outcomes occurred more frequently in the ICD group than in the CA group (5.6 vs. 54.5%, Log-rank P = 0.012). CONCLUSION: Catheter ablation is an effective alternative therapy for improving arrhythmic outcomes in patients with symptomatic BrS who decline ICD implantation. Our findings support the consideration of CA as an alternative treatment option in this population.

The causal associations of non-alcoholic fatty liver disease with blood pressure and the mediating effects of cardiometabolic risk factors: A Mendelian randomization study.

BACKGROUND AND AIMS: Non-alcoholic fatty liver disease (NAFLD) is prevalent in hypertensive people, but the causal effect remains unclear. We employed Mendelian randomization (MR) approach to assess the causality between NAFLD and different blood pressure (BP) parameters. METHOD AND RESULTS: Instrumental variables for genetically predicted NAFLD, including chronically elevated serum alanine aminotransferase levels (cALT) and imaging and biopsy-confirmed NAFLD, were obtained from a genome-wide association study (N = 164,197). Multiple MR methods were implemented, including Inverse variance weighted, MR-Egger, Maximum likelihood, Weighted median, Simple median, Penalised weighted median, MR-RAPS, and cML-MA. Outliers were detected using MR-PRESSO, and pleiotropy was assessed using MR-Egger intercept and Phenoscanner. Heterogeneity was quantified using Cochran's Q and Rucker's Q' tests. Potential shared risk factors were analyzed to reveal the mediating effect. A higher genetic predisposition to cALT was causally associated with an increased risk of elevated BP levels, resulting in 0.65 mmHg (95% CI, 0.42-0.87), 0.38 mmHg (95% CI, 0.25-0.50) and 0.33 mmHg (95% CI, 0.22-0.44) higher for systolic BP, diastolic BP and pulse pressure, respectively. When more stringent criteria were used, imaging and biopsy-confirmed NAFLD showed a 1.12 mmHg (95% CI, 0.94-1.30) increase in SBP and a 0.55 mmHg (95% CI, 0.39-0.70) increase in DBP. Risk factor and mediation analyses suggested type 2 diabetes and fasting insulin levels might mediate the causal relationship between NAFLD and BP. CONCLUSION: The two-sample MR analyses showed robust causal effects of genetically predicted NAFLD on 3 different BP indices. The shared genetic profile between NAFLD and BP may suggest important therapeutic targets and early interventions for cardiometabolic risk factors.

Development and Validation of Machine Learning-Based Models to Predict In-Hospital Mortality in Life-Threatening Ventricular Arrhythmias: Retrospective Cohort Study.

BACKGROUND: Life-threatening ventricular arrhythmias (LTVAs) are main causes of sudden cardiac arrest and are highly associated with an increased risk of mortality. A prediction model that enables early identification of the high-risk individuals is still lacking. OBJECTIVE: We aimed to build machine learning (ML)-based models to predict in-hospital mortality in patients with LTVA. METHODS: A total of 3140 patients with LTVA were randomly divided into training (n=2512, 80%) and internal validation (n=628, 20%) sets. Moreover, data of 2851 patients from another database were collected as the external validation set. The primary output was the probability of in-hospital mortality. The discriminatory ability was evaluated by the area under the receiver operating characteristic curve (AUC). The prediction performances of 5 ML algorithms were compared with 2 conventional scoring systems, namely, the simplified acute physiology score (SAPS-II) and the logistic organ dysfunction system (LODS). RESULTS: The prediction performance of the 5 ML algorithms significantly outperformed the traditional models in predicting in-hospital mortality. CatBoost showed the highest AUC of 90.5% (95% CI 87.5%-93.5%), followed by LightGBM with an AUC of 90.1% (95% CI 86.8%-93.4%). Conversely, the predictive values of SAPS-II and LODS were unsatisfactory, with AUCs of 78.0% (95% CI 71.7%-84.3%) and 74.9% (95% CI 67.2%-82.6%), respectively. The superiority of ML-based models was also shown in the external validation set. CONCLUSIONS: ML-based models could improve the predictive values of in-hospital mortality prediction for patients with LTVA compared with traditional scoring systems.

Deletion of BCG_2432c from the Bacillus Calmette-Guérin vaccine enhances autophagy-mediated immunity against tuberculosis.

BACKGROUND: Mycobacterium bovis bacillus Calmette-Guérin (BCG) is an attenuated live vaccine that provides insufficient protection against tuberculosis (TB), the underlying mechanisms for which remain unknown. Assuming that the BCG vaccine inherits immune evasive strategies from virulent parent M. bovis strains, we aimed to identify the associated genes and assess their effects on the vaccine efficacy. METHODS: Three genes, BCG_3174, BCG_1782, and BCG_2432c, associated with immune evasion were first identified via bioinformatics analysis and then confirmed in the genome of M. bovis and 12 commercial BCG vaccine substrains using Polymerase Chain Reaction (PCR) and DNA sequencing. These genes were disrupted to develop mutant strains, and their effects on autophagy and their protective efficacy were further compared with the BCG vaccine in vitro and in vivo. RESULTS: Of the three identified genes, only the disruption of BCG_2432c, namely ΔBCG_2432c, conferred stronger protection against intranasal TB in vaccinated mice, when compared with the BCG vaccine. ΔBCG_2432c showed a stronger ability to trigger intracellular ROS-mediated complete autophagic flux in infected THP-1 cells that resulted in higher antigen presentation. The improved protection could be attributed to early and increased IFN-γ+ CD4+ TEM and IL-2+ CD4+ TCM cells in the spleens and lungs of ΔBCG_2432c-vaccinated mice. CONCLUSIONS: The insufficient efficacy of the BCG vaccine is attributable to the important autophagy-inhibition gene BCG_2432c that blocks the autophagosome-lysosome pathway of antigen presentation. ΔBCG_2432c provides a promising platform to either replace the current BCG vaccine or develop vaccines that are more effective against TB.

Machine Learning-Based Model for Predicting Prolonged Mechanical Ventilation in Patients with Congestive Heart Failure.

BACKGROUND: Mechanical ventilation (MV) is widely used to relieve respiratory failure in patients with congestive heart failure (CHF). Prolonged MV (PMV) is associated with a poor prognosis. We aimed to establish a prediction model based on machine learning (ML) algorithms for the early identification of patients with CHF requiring PMV. METHODS: Twelve commonly used ML algorithms were used to build the prediction model. The least absolute shrinkage and selection operator (LASSO) regression was employed to select the key features. We examined the area under the curve (AUC) statistics to evaluate the prediction performance. Data from another database were used to conduct external validation. RESULTS: We screened out 10 key features from the initial 65 variables via LASSO regression to improve the practicability of the model. The CatBoost model showed the best performance for predicting PMV among the 12 commonly used ML algorithms, with favorable discrimination (AUC = 0.790) and calibration (Brier score = 0.154). Moreover, hospital mortality could be accurately predicted using the CatBoost model as well (AUC = 0.844). In the external validation, the CatBoost model also showed satisfactory prediction performance (AUC = 0.780), suggesting certain generalizability of the model. Finally, a nomogram with risk classification of PMV was shown in this study. CONCLUSION: The present study developed and validated a CatBoost model, which could accurately predict PMV in mechanically ventilated patients with CHF. Moreover, this model has a favorable performance in predicting hospital mortality in these patients.

Functional Screenings Identify Regulatory Variants Associated with Breast Cancer Susceptibility.

Genome-wide association studies (GWAS) have identified more than 2000 single nucleotide polymorphisms (SNPs) associated with breast cancer susceptibility, most of which are located in the non-coding region. However, the causal SNPs functioning as gene regulatory elements still remain largely undisclosed. Here, we applied a Dinucleotide Parallel Reporter sequencing (DiR-seq) assay to evaluate 288 breast cancer risk SNPs in nine different breast cancer cell lines. Further multi-omics analysis with the ATAC-seq (Assay for Transposase-Accessible Chromatin using sequencing), DNase-seq (DNase I hypersensitive sites sequencing) and histone modification ChIP-seq (Chromatin Immunoprecipitation sequencing) nominated seven functional SNPs in breast cancer cells. Functional investigations show that rs4808611 affects breast cancer progression by altering the gene expression of NR2F6. For the other site, rs2236007, the alteration promotes the binding of the suppressive transcription factor EGR1 and results in the downregulation of PAX9 expression. The downregulated expression of PAX9 causes cancer malignancies and is associated with the poor prognosis of breast cancer patients. Our findings contribute to defining the functional risk SNPs and the related genes for breast cancer risk prediction.

Electrocardiographic characteristics of idiopathic ventricular arrhythmias based on anatomy.

Idiopathic ventricular arrhythmia (IVA) is a term used to describe a spectrum of ventricular arrhythmia without structural heart disease (SHD). IVAs contain premature ventricular contractions (PVCs), nonsustained monomorphic ventricular tachycardia (VT), and sustained VT. Electrocardiography is a fundamental and important tool to diagnose and localize IVAs. More detailed, IVAs originating from different origins exhibit characterized ECGs due to their specific anatomic backgrounds. As catheter ablation becomes widely used to eliminate these arrhythmias, its high success rate is based on accurate localization of their origins. Therefore, these ECG characteristics show great importance for precise localization of their origins and subsequently successful ablation. This review aims to sum up ECG characteristics of IVAs based on anatomy and give brief introduction of mechanisms and treatment of IVAs.

Electrocardiographic tracking of left ventricular hypertrophy in hypertension: incidence and prognostic outcomes from the SPRINT trial.

BACKGROUND: This study explores the impact of intensive blood pressure (BP) control on left ventricular hypertrophy (LVH) incidence and evaluates the prognostic implications of LVH status (pre-existing/new-onset/persistent/regression) using Systolic Blood Pressure Intervention Trial (SPRINT) Electrocardiogram Data. METHODS: Poisson regression was used to assess new-onset LVH and LVH regression rates. Multivariable-adjusted Cox proportional hazard models determined the risk of adverse cardiovascular events (ACE), a composite of myocardial infarction (MI), non-MI acute coronary syndrome, stroke, heart failure, or cardiovascular death, alongside safety adverse events. RESULTS: In 8,016 participants, intensive BP control significantly reduced new-onset LVH (8.27 vs. 14.79 per 1000-person years; adjusted p<0.001) and increased LVH regression (14.89 vs. 11.89 per 1000-person years; adjusted p<0.001). Elevated ACE risk was notable in participants with pre-existing LVH [adjusted HR: 1.94 (95% CI: 1.25-2.99); p = 0.003], new-onset LVH [adjusted 1.74 (95% CI: 1.16-2.60); p = 0.007], and persistent LVH[adjusted HR: 1.96 (95% CI: 1.11-3.46); p = 0.020], compared to those without LVH. Intriguingly, LVH regression attenuated this risk increment [adjusted HR: 1.57 (95% CI: 0.98-2.53); p = 0.062]. Achieving a BP target of < 120/80 mmHg nullified the increased ACE risk in those with pre-existing LVH. CONCLUSIONS: Intensive BP control is instrumental in both reducing the emergence of LVH and fostering its regression. Pre-existing, new-onset LVH and persistent LV remain a predictor of adverse cardiovascular prognosis, whereas LVH regression and achieving on-treatment BP < 120/80 mmHg in pre-existing LVH individuals may further mitigate residual cardiovascular risk. CLINICAL TRIAL REGISTRATION: URL: ClinicalTrials.gov Unique Identifier: NCT01206062.

Efficacy of catheter ablation for ventricular tachycardia in ischemic cardiomyopathy patients without an ICD implantation.

BACKGROUND: The implantable cardioverter-defibrillator (ICD) prevents sudden cardiac death in patients with ischemic cardiomyopathy (ICM). Catheter ablation has been shown to effectively reduce ventricular tachycardia (VT) recurrence, yet its efficacy in patients without an ICD implantation remains uncertain. OBJECTIVE: We aimed to investigate the outcomes of ablation for VT in patients with ICM without a backup ICD. METHODS: Patients with ICM who received ablation for VT without an ICD implantation were included in this study. Ablation was guided by either activation mapping or substrate mapping. Endocardial ablation was the primary strategy; epicardial access was considered when endocardial ablation failed. The primary end point was VT recurrence during follow-up; secondary end points included cardiovascular rehospitalization, all-cause mortality, and a composite of these events. RESULTS: A total of 114 patients were included, with the mean age of 58.2 ± 11.1 years, 102 of whom (89.5%) were male. Twelve patients (10.5%) underwent endo-epicardial ablation, whereas the rest received endocardial ablation. With a median follow-up of 53.8 months (24.8-84.2 months), VT recurred in 45 patients (39.5%), and 6 patients (5.3%) died, including 2 sudden cardiac deaths. The recurrence rate of VT was significantly lower in patients undergoing endo-epicardial ablation than in those with endocardial ablation only (8.3% vs 43.1%; log-rank P = .032). After multivariate adjustment, epicardial ablation remained associated with a reduced risk of VT recurrence (hazard ratio, 0.14; 95% confidential interval, 0.02-0.98; P = .048). CONCLUSION: Patients with ICM undergoing VT ablation without a backup ICD experienced a notably low rate of arrhythmic death. Most recurrences proved nonlethal.

Lupeol alleviates autoimmune myocarditis by suppressing macrophage pyroptosis and polarization via PPARα/LACC1/NF-κB signaling pathway.

BACKGROUND: Autoimmune myocarditis, with increasing incidence and limited therapeutic strategies, is in urgent need to explore its underlying mechanisms and effective drugs. Pyroptosis is a programmed cell death that may contribute to the pathogenesis of myocarditis. Nonetheless, no direct evidence validated the role of pyroptosis in autoimmune myocarditis. Lupeol (Lup), a pentacyclic triterpene, possesses various biological activities such as antidiabetic properties. However, the effects of Lup on autoimmune myocarditis and pyroptosis remain unelucidated. PURPOSE: This study aimed to reveal the role of pyroptosis in autoimmune myocarditis and explore the protective effects of Lup, and its engaged mechanisms. METHODS: The experimental autoimmune myocarditis (EAM) mouse model was established by immunization with a fragment of cardiac myosin in Balb/c mice. Lup and MCC950 were administered after EAM induction. The protective effects were assessed by inflammation score, cardiac injury, chronic fibrosis, and cardiac function. Mechanistically, the effects of Lup on the M1 polarization and pyroptosis of macrophages were evaluated. Transcriptome sequencing and molecular docking were subsequently employed, and the underlying mechanisms of Lup were further explored in vitro with small interfering RNA and adenovirus. RESULTS: Administration of Lup and MCC950 alleviated EAM progression. Western blotting and immunofluorescence staining identified macrophages as the primary cells undergoing pyroptosis. Lup inhibited the expression of pyroptosis-associated proteins in macrophages during EAM in a dose-dependent manner. Furthermore, Lup suppressed pyroptosis in both bone marrow-derived macrophages (BMDMs) and THP-1-derived macrophages in vitro. In addition, Lup inhibited the M1 polarization of macrophages both in vivo and in vitro. Mechanistically, the protective effects of Lup were demonstrated via the suppression of the nuclear factor-κΒ (NF-κB) signaling pathway. Transcriptome sequencing and molecular docking revealed the potential involvement of peroxisome proliferator-associated receptor α (PPARα). Subsequently, we demonstrated that Lup activated PPARα to reduce the expression level of LACC1, thereby inhibiting the NF-κB pathway and pyroptosis. CONCLUSION: Our findings indicated the crucial role of macrophage pyroptosis in the pathogenesis of EAM. Lup ameliorated EAM by inhibiting the M1 polarization and pyroptosis of macrophages through the PPARα/LACC1/NF-κB signaling pathway. Thus, our results provided a novel therapeutic target and agent for myocarditis.

Sex differences in ventricular arrhythmias epidemiology, risk factors, and mortality in congestive heart failure.

BACKGROUND: Female patients are underrepresented in randomized controlled clinical trials and registries of ventricular arrhythmia (VA). Personalized prevention and therapies require an understanding of sex differences in risk factors and prognosis of VA. OBJECTIVE: We aimed to assess sex differences in the incidence, risk factors, and mortality of VA in congestive heart failure (HF) patients. METHODS: This study included 10,889 patients (mean [SD] age, 73.8 [13.4] years; 5917 [53.8%] male) with congestive HF, of which 1555 (14.3%) patients developed VA during hospitalization. VA incidence, potential risk factors, and in-hospital mortality were evaluated in both sexes. RESULTS: Men were more strongly associated with incident VA compared with women (odds ratio [OR]: 2.006, 95% CI: 1.790-2.248, p < 0.001). Thirteen potential predictors, which accounted for 91.0% of the risk of VA in men and 88.2% in women, were included in this study. There were significant interactions by sex in the association between incident VA, atrial fibrillation (AF) (relative risk ratio = 0.730, 95% CI: 0.571-0.933, interaction p = 0.012), and non-ischemic cardiomyopathy (NICM) (relative risk ratio = 1.391, 95% CI: 1.029-1.872, interaction p = 0.030). Congestive HF patients developed with VA had an approximately 1.5-fold risk of in-hospital mortality, which was not affected by sex. CONCLUSIONS: In congestive HF patients, incident VA was an independent risk factor of in-hospital mortality, and male sex was strongly associated with an increased risk of VA. Awareness of sex differences in the association of AF and NICM with VA may enhance therapeutic decisions, thus improving their clinical outcomes.

Causal effects between atrial fibrillation and heart failure: evidence from a bidirectional Mendelian randomization study.

BACKGROUND: Observational studies have suggested a close association between atrial fibrillation (AF) and heart failure (HF), yet the causal effect remains uncertain. In this study, we employed a bidirectional Mendelian randomization analysis to investigate the causal effect of one disease on the other. METHODS: Genetic instrumental variables were obtained from large-scale summary-level genome-wide association studies of AF (n = 1,030,836) and HF(n = 1,665,481), respectively. Two-sample Mendelian randomization was conducted to establish causal inferences. Inverse-variance weighted (IVW) was the primary estimate, while additional analyses including MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO), MR-Egger, and Weighted median were performed to validate robustness and identify pleiotropy. RESULTS: After accounting for confounding variables, MR analysis suggested a potential causal relationship between AF and HF. An augmented genetic predisposition to atrial fibrillation was associated with an elevated risk of heart failure (odds ratio (OR) = 1.18, 95% confidence interval (CI):1.14-1.22). Likewise, genetically determined heart failure also increased the risk of heart failure (OR = 1.44, 95%CI:1.23-1.68). The robustness of the findings was corroborated through MR sensitivity analyses, and the causal estimates remained consistent when the instrument P-value threshold was tightened. CONCLUSIONS: Our bidirectional Mendelian randomization study supports a reciprocal causal relationship between AF and HF. The shared genetic profile of these conditions may provide crucial insights into potential therapeutic targets for the prevention and progression of both disorders. These findings underscore the necessity for further investigation into the underlying molecular mechanisms linking AF and HF, as well as the potential for personalized treatment strategies grounded in genetic profiling.

Use of machine learning algorithms to predict life-threatening ventricular arrhythmia in sepsis.

Aims: Life-threatening ventricular arrhythmias (LTVAs) are common manifestations of sepsis. The majority of sepsis patients with LTVA are unresponsive to initial standard treatment and thus have a poor prognosis. There are very limited studies focusing on the early identification of patients at high risk of LTVA in sepsis to perform optimal preventive treatment interventions. We aimed to develop a prediction model to predict LTVA in sepsis using machine learning (ML) approaches. Methods and results: Six ML algorithms including CatBoost, LightGBM, and XGBoost were employed to perform the model fitting. The least absolute shrinkage and selection operator (LASSO) regression was used to identify key features. Methods of model evaluation involved in this study included area under the receiver operating characteristic curve (AUROC), for model discrimination, calibration curve, and Brier score, for model calibration. Finally, we validated the prediction model both internally and externally. A total of 27 139 patients with sepsis were identified in this study, 1136 (4.2%) suffered from LTVA during hospitalization. We screened out 10 key features from the initial 54 variables via LASSO regression to improve the practicability of the model. CatBoost showed the best prediction performance among the six ML algorithms, with excellent discrimination (AUROC = 0.874) and calibration (Brier score = 0.157). The remarkable performance of the model was presented in the external validation cohort (n = 9492), with an AUROC of 0.836, suggesting certain generalizability of the model. Finally, a nomogram with risk classification of LTVA was shown in this study. Conclusion: We established and validated a machine leaning-based prediction model, which was conducive to early identification of high-risk LTVA patients in sepsis, thus appropriate methods could be conducted to improve outcomes.