This review examines the bidirectional relationship between the gut microbiota and cardiovascular diseases (CVDs), aiming to understand how microbial dysbiosis contributes to CVDs, including atherosclerosis, hypertension, and heart failure. Recent research emphasizes the gut microbiota’s role in modulating immunity via SCFAs and tryptophan metabolites, maintaining intestinal barrier integrity, and producing metabolites such as SCFAs (acetate, propionate, butyrate) and pro‐atherogenic TMAO. Dietary patterns, particularly the Mediterranean versus Western diet, significantly influence gut microbiota composition and CVD risk. Polyphenols and exercise have shown positive effects on gut microbiota and cardiovascular outcomes. A significant interplay exists between gut microbiota and cardiovascular health. Dysbiosis and metabolites like TMAO and LPS are implicated in CVD, while SCFAs and a balanced microbiota offer protection. Future research should focus on precision medicine, next‐gen probiotics, optimized FMT, and multiomics approaches to identify personalized CVD therapies.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia globally, linked to significant cardiovascular morbidity and mortality. Catheter ablation has emerged as a primary therapeutic approach, yet substantial recurrence rates limit its long-term efficacy. This review critically examines the molecular mechanisms underlying AF recurrence post-ablation, synthesizing recent findings from current literature. Key molecular pathways identified include structural remodeling mediated by fibrosis involving transforming growth factor-beta 1 (TGF-β1) and matrix metalloproteinases (MMPs), ion-channel dysregulation, inflammatory pathways, autonomic nervous system imbalance, and genetic and epigenetic alterations. Despite considerable advances, critical gaps persist due to small, heterogeneous studies and insufficient long-term follow-up. Comprehensive mechanistic research integrating genomics, proteomics, and advanced imaging is urgently needed to better characterize these pathways. Future studies must validate biomarkers such as TGF-β1, MMPs, connexins, and novel markers like GDF-15 and relaxin. Clinical translation of these molecular insights through precision diagnostics and personalized interventions holds great promise to enhance patient selection, optimize ablation strategies, reduce recurrence, and ultimately improve clinical outcomes in AF management.

Catheter ablation (CA) was found to outperform antiarrhythmic drug therapy (AAD), and it is a key treatment for rhythm control for patients with symptomatic atrial fibrillation (AF). Nevertheless, the procedure’s effectiveness is limited by recurrence rates. Identifying determinants of effective ablation is critical for optimizing patient selection, operative results, and long-term rhythm management strategies. In this state-of-the-art review, we have comprehensively discussed the various factors that can determine the recurrence of AF after a successful CA.

BACKGROUND Non-ST-elevation myocardial infarction (NSTEMI) is a prevalent acute coronary syndrome among the elderly, a population often underrepresented in clinical trials. Frailty, a marker of physiologic vulnerability, may influence the risks and benefits of percutaneous coronary intervention (PCI) in these patients. AIM To evaluate the impact of frailty status on in-hospital outcomes among patients aged ≥ 75 years with NSTEMI undergoing PCI. METHODS We conducted a retrospective cohort study using the 2021-2022 National Inpatient Sample to evaluate the impact of frailty on in-hospital outcomes among NSTEMI patients aged ≥ 75 years undergoing PCI. Patients were stratified into three frailty categories using the Hospital Frailty Risk Score. Multivariable logistic and generalized linear models with interaction terms assessed the association between frailty and clinical outcomes. RESULTS Among 456690 NSTEMI admissions, 37.95%, 50.71%, and 11.34% were categorized as low, intermediate, and high frailty, respectively. PCI use declined with increasing frailty (35.0% in low vs 7.5% in high; P < 0.001). Adjusted mortality was lower with PCI across all frailty levels [odds ratios (OR): 0.27 (low), 0.37 (intermediate), 0.43 (high); all P < 0.001]. However, the mortality benefit was attenuated with increasing frailty (interaction OR: 1.56 and 1.83 for intermediate and high vs low frailty; P < 0.001). Frailty was independently associated with higher odds of complications, including acute kidney injury, respiratory failure, delirium, and bleeding. PCI was associated with shorter hospital stays in low (-0.90 days) but longer in the high-frail category (+2.47 days; P < 0.001), and increasing frailty correlated with significantly higher hospital charges. CONCLUSION In elderly NSTEMI patients, PCI conferred a survival benefit across all frailty strata, although with a diminishing magnitude as frailty increased. Frailty correlated with increased complications and healthcare resource utilization.

Background: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, increasingly prevalent worldwide. Type 2 diabetes mellitus (T2DM) is a major chronic disorder and a significant risk factor for AF, contributing to high morbidity and mortality. Metformin monotherapy can contribute to the reduced occurrence of adverse cardiovascular outcomes in patients with T2DM, but its effects on AF are understudied. This meta-analysis evaluates the association of metformin with the risk of incident AF among patients with T2DM on metformin. Methods: Databases, including PubMed, Google Scholar, and EMBASE, were screened through November 2024 for studies evaluating the association between metformin and new-onset AF in patients with T2DM. Comprehensive Meta-Analysis (CMA) version 4, by Biostat, Inc., utilizing a random effects model, was used to pool hazard ratios (HR) and 95% confidence intervals (CI). A meta-regression analysis was also performed to identify factors that may have influenced the results. A p-value < 0.05 was considered statistically significant. Results: A total of seven studies, comprising 4,017,929 patients with T2DM, having a mean age of 62.82 years and 52.5% males, were included. Metformin was associated with a statistically significantly lower risk of new-onset AF among patients with T2DM compared to other hypoglycemic agents (aHR: 0.85; 95% CI 0.76–0.94; p = 0.002). Meta-regression analysis identified age as a significant moderator of the treatment effect (β = −3.15, p = 0.001). Conclusions: Metformin is associated with a lower risk of new-onset AF among patients with T2DM compared to other hypoglycemic agents. Furthermore, age-related attenuation of this association was observed, with older patients with T2DM showing a weaker association.

BACKGROUND There is widespread debate about the impact of metabolically healthy obesity (MHO) on cardiovascular outcomes. However, studies have not exclusively examined the impact of MHO on cardiovascular outcomes in the postmenopausal population. AIM To explore the prevalence of MHO and its relationship with hospitalization outcomes, including major adverse cardiac or cerebrovascular events (MACCE), in postmenopausal women. METHODS We extracted data from the National Inpatient Sample 2020 database using International Classification of Disease, Tenth Revision, Clinical Modification codes for all admissions of postmenopausal women. We excluded patients with diabetes, hypertension, and hyperlipidemia to obtain metabolically healthy patients and then identified patients with obesity to create obese and non-obese cohorts. We used a 1:1 propensity score matching method to match patients with and without MHO based on age, and then we did a multivariable regression analysis for in-hospital MACCE. RESULTS In 2020, 1304185 metabolically healthy postmenopausal women were admitted; 148250 (11.4%) had MHO. After propensity score matching for age, a statistically significant difference was observed in overall MACCE [odds ratio (OR): 1.08, 95% confidence interval (CI): 1.01-1.16, P = 0.028] among MHO and non-MHO cohorts, especially in patients of African-American ethnicity (OR: 1.23, 95%CI: 1.01-1.49, P = 0.035) and the lowermost income quartile (OR: 1.24, 95%CI: 1.06-1.44, P = 0.007). CONCLUSION Postmenopausal patients with MHO are at risk of MACCE, especially black patients and those with lower incomes. Larger prospective studies can demystify MHO’s impact on cardiovascular outcomes among postmenopausal women.