Enhanced Cardiomyocyte NLRP3 Inflammasome Signaling Promotes Atrial Fibrillation

Effect of low dose colchicine on long term recurrence after atrial fibrillation ablation

BACKGROUND

Colchicine is commonly used early after atrial fibrillation (AF) ablation to reduce inflammation and reduce AF recurrence, but there is limited long-term efficacy data.

OBJECTIVE

To evaluate the effect of low dose colchicine use on long-term AF recurrence after AF ablation.

METHODS

From 2013 to 2021, all AF ablations performed at a single tertiary care medical center were analyzed for colchicine use, clinical and procedural characteristics, and AF recurrence. The colchicine dose was 0.3-0.6 mg once daily for 30 days. The primary outcome was AF recurrence, defined as AF detection for more than 30 s after a three-month blanking period. Propensity score matching (PSM, 1:1 match) was performed using covariates that were significant predictors of AF recurrence in prior studies. The minimum duration of follow-up was 6 months. Kaplan-Meier analysis was conducted to assess time to AF recurrence in the entire cohort and the PSM cohort.

RESULTS

The study population consisted of 1568 AF ablations in 1412 patients (67 % male, age 65 ± 7 years and mean follow up 34 ± 14 months); 78 % of the patients received colchicine. Colchicine use was associated with decreased AF recurrence (HR 0.78, CI 0.63-0.96, p = 0.022). After PSM there were 275 patients in each group. AF recurrence was lower with colchicine (HR 0.71, CI 0.53-0.96, p = 0.026).

CONCLUSIONS

Low dose colchicine use was associated with lower long-term AF recurrence after AF ablation. A randomized, placebo-controlled trial is warranted to confirm if low dose colchicine should be used routinely after AF ablation.

m6A reader YTHDF2 governs the onset of atrial fibrillation by modulating Cacna1c translation

Atrial fibrillation (AF) is the most common arrhythmia, which is tightly associated with the abnormal expression and function of ion channels in the atrial cardiomyocytes. N6-methyladenosine (m6A), a widespread chemical modification in eukaryotic mRNA, is known to play a significant regulatory role in the pathogenesis of heart disease. However, the significance of m6A regulatory proteins in the onset of AF remains unclear. Here, we demonstrate that the m6A reader protein YTHDF2 regulates atrial electrical remodeling and AF onset by modulating the Cav1.2 expression. Firstly, YTHDF2 expression was selectively upregulated in rat atrial cardiomyocytes with AF. Secondly, YTHDF2 knockout reduced AF susceptibility in mice. Thirdly, the knockout of YTHDF2 increased Cav1.2 protein levels in an m6A-in-dependent manner, ultimately prolonging the atrial myocardial refractory period, a critical electrophysiological substrate for the onset of AF. Fourthly, the N-terminal domain of YTHDF2 was identified as critical for Cacna1c mRNA translation regulation. Overall, our findings unveil that YTHDF2 can alter Cav1.2 protein expression in an m6A-independent manner, thereby facilitating the onset of AF. Our study suggests that YTHDF2 may be a potential intervention target for AF.

Prevention of New-Onset Heart Failure in Atrial Fibrillation: The Role of Pharmacological Management

Atrial fibrillation (AF) is the most common type of chronic arrythmia, with a lifetime prevalence of one in every three to five individuals above the age of 45 years. The higher heart rate, abnormal rhythm and inflammation caused by AF lead to changes in the function and structure of the heart. This, over time, can culminate in heart failure. In patients with AF, the lifetime prevalence of new-onset heart failure is twice that of stroke. The development of new-onset heart failure in AF is associated with high mortality. Despite the emphasis that AF guidelines put on preventing cardiovascular comorbidities, there is limited evidence regarding pharmacological therapies to prevent incident heart failure in individuals with AF. Specifically, the association between the use of rate control agents and incident heart failure in this population is unknown. Whilst rhythm control may reduce the risk of heart failure, the comparative effect of each pharmacological agent is not clear. In select subgroups of patients with AF, the choice of direct-acting oral anticoagulants and their optimal dosing has been attributed to a lower risk of new-onset heart failure. Future research is needed to identify an evidence-based approach to minimizing the development of heart failure in patients with AF.

Analysis of key proinflammatory mechanisms in cardiovascular pathology through stimulation with lipopolysaccharide and urban particulate matter in mouse atrial cardiomyocytes

Air pollution has emerged as one of the leading causes of mortality, aggravating cardiovascular diseases. Urban-particulate matter (PM) can accumulate in the cardiovascular system and through inflammation, trigger systemic damage. One of the key mechanisms of this process could be related to the activation of the inflammasome through the pre-existence of a low-grade endotoxemia and PM presence in the cells. Herein, we studied the deleterious effects of urban-PM and Lipopolysaccharide (LPS) exposure in a HL-1 mouse cardiomyocyte cell line. Urban-PM induced biological changes, including mRNA expression of pro-inflammatory genes, intracellular reactive oxygen species (ROS) generation and overexpression of inflammasome-related and structural proteins. The results revealed that urban-PM with different ultrastructure, as determined by transmission electron microscopy (TEM), is embedded inside the cardiomyocytes, leading to the recognition and activation of the inflammatory process. The increase of ROS levels and mRNA levels of pro-inflammatory genes were similarly observed in a dose-dependent manner. In addition, components and proteins of the inflammasome such as associated speck-like protein containing a CARD (ASC), caspase-1 and IL-1β were differentially overexpressed in treated HL-1 cells, as well as structural proteins like Connexin 43 (Cx43). These results provide new insights into the mechanisms that mediate innate pro-inflammatory activation in cardiomyocytes in response to air suspension pollutants.

Heart of the matter: mitochondrial dynamics and genome alterations in cardiac aging

Cardiac pathological aging is a serious health issue, with cardiovascular diseases still being a leading cause of deaths worldwide. Therefore, there is an urgent need to identify culprit factors involved in this process. In the last decades, mitochondria, which are crucial for cardiac function, have emerged as major contributors. Mitochondria are organelles involved in a plethora of metabolic pathways and cell processes ranging from ATP production to calcium homeostasis or regulation of apoptotic pathways. This review provides a general overview of the pathomechanisms involving mitochondria during cardiac aging, with a focus on the role of mitochondrial dynamics and mitochondrial DNA (mtDNA). These mechanisms involve imbalanced mitochondrial fusion and fission, loss of mtDNA integrity leading to tissue mosaic of mitochondrial deficiency, as well as mtDNA release in the cytoplasm, promoting inflammation via the NLRP3, cGAS/STING and TLR9 pathways. Potential links between mtDNA, mitochondrial damage and the accumulation of senescent cells in the heart are also discussed. A better understanding of how these factors impact on heart function and accelerate its pathological aging should lead to the development of new therapies to promote healthy aging and restore age-induced cardiac dysfunction.

Anti-inflammatory Therapies for Ischemic Heart Disease

PURPOSE OF REVIEW

The inclusion of immunomodulatory strategies as supportive therapies in ischemic heart disease (IHD) has garnered significant support over recent years. Several such approaches appear to be unified through their ultimate target, the NLRP3 inflammasome. This review presents a brief update on immunomodulatory strategies in the continuum of conditions constituting ischemic heart disease and emphasising on the seemingly unifying mechanism of NLRP3 activation as well as modulation across these conditions.

RECENT FINDINGS

The NLRP3 inflammasome is a multiprotein complex assembled upon inflammatory stimulation, causing the release of pro-inflammatory cytokines and initiating pyroptosis. The NLRP3 pathway is relevant in inflammatory signalling of cardiac immune cells as well as non-immune cells in the myocardium, including cardiomyocytes, fibroblasts and endothelial cells. In addition to a focus on clinical outcome and efficacy trials of targeting NLRP3-related pathways, the potential connection between immunomodulation in cardiology and the NLRP3 pathway is currently being explored in preclinical trials. Colchicine, cytokine-based approaches and SGLT2 inhibitors have emerged as promising agents. However, the conditions comprising IHD including atherosclerosis, coronary artery disease (CAD), myocardial infarction (MI) and ischemic cardiomyopathy/heart failure (iCMP/HF) are not equally amenable to immunomodulation with the respective drugs. Atherosclerosis, coronary artery disease and ischemic cardiomyopathy are affected by chronic inflammation, but the immunomodulatory approach to acute inflammation in the post-MI setting remains a pharmacological challenge, as detrimental and regenerative effects of myocardial inflammation are initiated in unison. The NLRP3 inflammasome lies at the center of cell mediated inflammation in IHD. Recent trial evidence has highlighted anti-inflammatory effects of colchicine, interleukin-based therapy as well as SGLT2i in IHD and that the respective drugs modulate the NLRP3 inflammasome.

p300 upregulates Ikur in atrial cardiomyocytes through activating NLRP3 inflammasome in hypertension

BACKGROUND

The nucleotide-binding oligomerization domain [NOD-], leucine-rich repeats [LRR-], and Pyrin domain-containing protein 3 (NLRP3) inflammasome plays an essential role in hypertension-related atrial fibrillation (AF). p300 is involved in cardiovascular inflammation. In this study, we aimed to investigate the role of p300 in NLRP3 inflammasome activation and its subsequent impact on the Ikur current in angiotensin II (Ang II)-induced HL-1 cells and Ang II-infused mice.

METHODS

Expression levels of p300, Kv1.5, and NLRP3 in left atrial appendage (LAA) tissues from AF and sinus rhythm (SR) patients were detected by Western blot. A hypertension mouse model was established in p300 knockout (p300-KO) mice via Ang II infusion, and AF incidence was assessed by electrocardiogram (ECG) after rapid atrial pacing. In vitro, the expression level of p300 in HL-1 cells was modulated by adenoviral overexpression, curcumin (an inhibitor of p300) treatment, and smal interfering RNA (siRNA) knockdown. NLRP3 inflammasome activation was evaluated by Western blot and enzyme-linked immunosorbent assay, and electrophysiological properties of HL-1 cells were analyzed using whole-cell patch-clamp recordings. Co-immunoprecipitation assays were performed to investigate the interaction between p300 and nuclear factor kappa B (NF-κB).

RESULTS

The expression levels of p300, Kv1.5, and NLRP3 were found to be significantly higher in the LAA tissue of AF patients compared to SR patients. p300-KO decreased AF incidence in Ang II-infused mice by impairing NLRP3 inflammasome activation. p300-OE facilitated NLRP3 inflammasome activation, which subsequently increased the Ikur density and shortened the action potential duration of HL-1 cells. Both curcumin (p300 inhibitor) and p300-siRNA treatments reversed Ang II-induced atrial electrical remodeling and NLRP3 inflammasome activation. Moreover, co-immunoprecipitation showed that p300 interacts with NF-κB to promote NLRP3 inflammasome activation.

CONCLUSIONS

p300 participates in hypertension-induced AF susceptibility by interacting with NF-κB to activate the NLRP3 inflammasome, which subsequently upregulates the transmembrane current of Ikur in atrial cardiomyocytes.

Tamibarotene directly targets the NACHT domain of NLRP3 to alleviate acute myocardial infarction

The aberrant activation of the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome has been implicated in the exacerbation of myocardial damage and the subsequent development of heart failure following myocardial infarction (MI). Inhibiting NLRP3 inflammasome activation offers a promising therapeutic strategy for mitigating MI-related injury, although no NLRP3 inhibitors have received Food and Drug administration (FDA) approval to date. To identify novel NLRP3 inflammasome inhibitors through the repurposing of FDA-approved drugs, Tamibarotene emerged as a potent inhibitor with a favorable safety profile. Mechanistically, Tamibarotene inhibits NLRP3 inflammasome activation independently of retinoic acid receptor activation, binding to Phe410 and Ile417 within the nucleotide-binding and oligomerization (NACHT) domain in an ATPase activity-dependent manner. This interaction further inhibits the assembly of the NLRP3 inflammasome. In a murine model of MI, Tamibarotene significantly reduced myocardial damage and improved cardiac function by inhibiting NLRP3 inflammasome activation. In summary, NLRP3 has been identified as a direct target of Tamibarotene for myocardial repair following MI, indicating that Tamibarotene could serve as a potential precursor for the development of innovative NLRP3 inhibitors.

Identification of anti-inflammatory and anti-cancer compounds targeting the NF-κB-NLRP3 inflammasome pathway from a phytochemical library of the Sideritis genus

ETHNOBOTANICAL RELEVANCE

For centuries, the aerial parts of Sideritis species have been known for their medicinal properties as herbal teas. Although the antioxidant and anti-inflammatory properties of the genus have been widely documented, the underlying mechanisms are yet to be sufficiently clarified.

AIM OF THE STUDY

We investigated the anti-inflammatory and anticancer activities of phytochemicals of the Sideritis genus.

MATERIAL AND METHODS

Through literature mining, a chemical library containing 657 components of the Sideritis genus was formed. We studied these compounds for binding to NLRP3 and NF-κB proteins in silico by virtual drug screening and molecular docking, and in vitro by microscale thermophoresis (MST). Liquid chromatography-high-resolution mass spectrometry analysis (LC-HRMS) was performed in the Sideritis extracts. One of the identified compounds, verbascoside, was investigated for its cytotoxic activity by mining a panel of 49 tumor cell lines in the data repository of the National Cancer Institute (NCI, USA).

RESULTS

Virtual screening and molecular docking results highlighted two compounds targeting both proteins of interest, i.e., verbascoside (acteoside) and apigenin 7,4'-bis(trans-p-coumarate), as both had lowest binding energies of less than -10 kcal/mol. Using MST, we then verified that both compounds bound to the target proteins. Verbascoside bound to NLRP3 and NF-κB with Kd values of 0.67 ± 0.18 μM and 0.01 ± 0.08 μM, while apigenin 7,4'-bis(trans-p-coumarate) had Kd values of 4.60 ± 1.66 μM and 0.27 ± 0.75 μM, respectively. Verbascoside was abundant in the Sideritis extracts, according to LC-HRMS analysis. Since inflammation is strongly related to carcinogenesis, we investigated the anticancer activity of verbascoside in the second part of this study. We investigated the activity of verbascoside in 49 tumor cell lines of the NCI. Comparing its activity with 81 standard anticancer drugs revealed numerous interactions with DNA-damaging agents (alkylators, topoisomerase I/II inhibitors, antimetabolites), indicating that verbascoside may also affect the DNA of tumor cells. We further investigated the involvement of verbascoside in several main drug resistance mechanisms, i.e., ABC transporters, oncogenes, tumor suppressors, cellular proliferation rates, and other parameters. Except for the correlation to the mutational status of NRAS, no other significant relationships were found, indicating that verbascoside is not involved in most of the common drug resistance mechanisms. Two-dimensional cluster analysis-based heatmap generation of a proteomic profile from 40 out of 3171 proteins revealed a significant correlation between the expression of these proteins in 49 tumor cell lines, and the cellular response to verbascoside. This indicates that the presence of these proteins is a determinant for sensitivity or resistance to this natural product.

CONCLUSION

The database established here represents a valuable resource for the screening of bioactivites of the Sideritis genus. The experimental validation of the anti-inflammatory and cytotoxic activities of selected compounds proved that virtual drug screening and molecular docking are suitable tools for the identification of putative drug candidates. Verbascoside was among the top 10 compounds binding to two key anti-inflammatory proteins, NLRP3 and NF-kB. Additionally, data from the NCI indicate that verbascoside is not linked to main drug resistance mechanisms.

Atrial cardiomyocyte-restricted cleavage of gasdermin D promotes atrial arrhythmogenesis

BACKGROUND AND AIMS

Enhanced inflammatory signalling causally contributes to atrial fibrillation (AF) development. Gasdermin D (GSDMD) is an important downstream effector of several inflammasome pathways. However, the role of GSDMD, particularly the cleaved N-terminal (NT)-GSDMD, in non-immune cells remains elusive. This study aimed to elucidate the function of NT-GSDMD in atrial cardiomyocytes (ACMs) and determine its contribution to atrial arrhythmogenesis.

METHODS

Human atrial appendages were used to assess the protein levels and localization. A modified adeno-associated virus 9 was employed to establish ACM-restricted overexpression of NT-GSDMD in mice.

RESULTS

The cleavage of GSDMD was enhanced in ACMs of AF patients. Atrial cardiomyocyte-restricted overexpression of NT-GSDMD in mice increased susceptibility to pacing-induced AF. The NT-GSDMD pore formation facilitated interleukin-1β secretion from ACMs, promoting macrophage infiltration, while up-regulating 'endosomal sorting complexes required for transport'-mediated membrane-repair mechanisms, which prevented inflammatory cell death (pyroptosis) in ACMs. Up-regulated NT-GSDMD directly targeted mitochondria, increasing mitochondrial reactive oxygen species (ROS) generation, which triggered proarrhythmic calcium-release events. The NT-GSDMD-induced arrhythmogenesis was mitigated by the mitochondrial-specific antioxidant MitoTEMPO. A mutant NT-GSDMD lacking pore-formation capability failed to cause mitochondrial dysfunction or induce atrial arrhythmia. Genetic ablation of Gsdmd prevented spontaneous AF development in a mouse model.

CONCLUSIONS

These findings establish a unique pyroptosis-independent role of NT-GSDMD in ACMs and arrhythmogenesis, which involves ROS-driven mitochondrial dysfunction. Mitochondrial-targeted therapy, either by reducing ROS production or inhibition of GSDMD, prevents AF inducibility, positioning GSDMD as a novel therapeutic target for AF prevention.

4-octyl Itaconate Attenuates Acute Pancreatitis and Associated Lung Injury by Suppressing Ferroptosis in Mice

Acute pancreatitis (AP) is a common gastrointestinal emergency requiring hospitalization. In recent years, several studies have demonstrated a role for 4-octyl itaconate (4-OI) in anti-inflammatory and oxidative stress injury. However, the potential effects of 4-OI in AP have not been investigated. Caerulein and LPS were used to induce experimental AP models in mice and AR42J cells and then studied by histopathology, biochemical, and molecular analysis. Ferroptosis inhibitor ferrostatin-1 effectively improves pancreatic injury and reduces lipid peroxidation products in experimental AP mice. 4-OI treatment significantly alleviated pancreatic and AP-associated lung injury and inflammation in experimental AP mice by inhibiting ferroptosis. The ferroptosis activator Erastin blocked the protective effect of 4-OI against pancreatic injury in AP, validating that 4-OI alleviates pancreatitis injury through ferroptosis. In vitro experiments further confirmed that 4-OI treatment ameliorated AP-induced pancreatic injury by inhibiting ferroptosis. Our study, for the first time, found that 4-OI ameliorates AP and AP-related lung injury by inhibiting ferroptosis in experimental AP mice, providing a new therapeutic target for alleviating AP.

Decreased METTL3 in atrial myocytes promotes atrial fibrillation

AIMS

Methyltransferase like 3 (METTL3) plays a crucial role in cardiovascular diseases, but its involvement in atrial fibrillation (AF) remains unclear. The study aims to explore the relationship between METTL3 and AF in atrial myocytes.

METHODS AND RESULTS

The protein level of METTL3 was evaluated in left atrial appendages (LAAs) from patients with persistent AF and in experimental AF models. cAMP-responsive element modulator (CREM) transgenic mice and CaCl2-acetylcholine (ACh)-injected mice were used as AF mice models. Methyltransferase like 3 was globally and atrial conditionally deleted in vivo to assess its role in AF. Confocal fluorescence microscopy was employed to examine calcium handling in atrial myocytes. Methylated RNA immunoprecipitation sequencing was performed to identify the downstream target genes of METTL3. Methyltransferase like 3 protein and RNA N6-methyladenosine (m6A) modification levels were significantly reduced in the LAAs of patients with AF and experimental AF models. Genetic inhibition of METTL3 promoted the development of AF in CREM transgenic mice and CaCl2-ACh-injected mice. Knockdown of METTL3 in atrial myocytes resulted in enhanced calcium handling. Reduced METTL3 levels increased SR Ca2+-ATPase Type 2a activity by up-regulating protocadherin gamma subfamily A, 10. Decreased METTL3 protein in atrial myocytes was attributed to down-regulation of cAMP-responsive element-binding protein 1/ubiquitin-specific peptidase 9 X-linked axis.

CONCLUSION

Our study established the pathophysiological role of METTL3 involved in the development of AF and provided a potential mechanism-based target for its treatment.

The gut microbial metabolite phenylacetylglutamine increases susceptibility to atrial fibrillation after myocardial infarction through ferroptosis and NLRP3 inflammasome

Myocardial infarction (MI) is an important risk factor for the development of atrial fibrillation (AF), and the gut microbial metabolite phenylacetylglutamine (PAGln) is strongly associated with the prognosis of MI patients. However, whether PAGln is involved in the regulation of AF after MI is currently unknown. Therefore, the present study aimed to explore the effect of PAGln on the susceptibility to AF after MI. MI model was constructed by surgically ligating the left anterior descending branch of the coronary artery. PAGln was administered by intraperitoneal injection for 7 consecutive days starting after surgery and then investigated by histopathologic, molecular biological, and electrophysiologic studies. Myocardial ischemia resulted in intestinal barrier dysfunction and significantly increased circulating levels of PAGln. Compared with the myocardial ischemia group, administration of PAGln significantly exacerbated atrial fibrosis and atrial electrical remodeling in mice after myocardial ischemia, as evidenced by shortening of the ERP (at varying pacing cycle lengths of 40, 60, 80, and 100), ion channel remodeling (Nav1.5, Cav1.2, and Kv1.5), and decreased expression of CX40, which led to an increase in the susceptibility to AF (54.5% vs. 90.9%, P < 0.05). In addition, administration of PAGln further exacerbated MI-induced intestinal barrier dysfunction compared with the MI group. Mechanistically, PAGln may affect atrial remodeling and AF susceptibility after MI by modulating ferroptosis and NLRP3 inflammasome. The present study preliminarily reveals that the gut microbial metabolite PAGln exacerbates post-MI AF remodeling and AF susceptibility, possibly through ferroptosis and activation of NLRP3 inflammasome.

[Colchicine-Phoenix from the ashes]

Colchicine is an anti-inflammatory herbal medicine with a history stretching back thousands of years. It is a cornerstone in the acute and prophylactic treatment of gout and has secured a permanent place in the standard pharmacological repertoire for familial Mediterranean fever, pericarditis, neutrophilic dermatoses, Behçet's disease and severe aphthous ulcers refractory to oral treatment. The US Food and Drug Administration (FDA) has recently approved colchicine to reduce the risk of myocardial infarction, stroke, coronary revascularization and cardiovascular death in adult patients with established atherosclerotic disease or with multiple risk factors for cardiovascular diseases. The recommendation level for cardiovascular prophylaxis was raised from IIb to IIa in the current European Society of Cardiology (ESC) guidelines from 2024. Clinical studies in recent years also demonstrated an effect for acute coronary syndrome and atrial fibrillation. This review article highlights the efficacy and safety profile of colchicine and provides insights into recent and potential future evidence-based fields of application.

Associations between plasma caspase-1 levels and cardiovascular disease, with the mediating role of metabolic syndrome

AIMS

This study aimed to explore the association between plasma caspase-1 levels and cardiovascular disease (CVD), as well as the potential mediating role of metabolic syndrome (Mets) in the association.

METHODS

This study analyzed the UK Biobank Precision Proteomics Project (UKB-PPP), which detected plasma caspase-1 levels in participants. CVD was defined by ICD-9/ICD-10 codes. The Cox proportional hazards regression model was used to explore the hazard ratio (HR) of plasma caspase-1 levels with CVD. Mediation analysis was conducted to investigate the mediating effect of Mets and its components on this relationship.

RESULTS

This study included a total of 41,499 participants. Among them, 4869 (11.7 %) participants were documented to have developed CVD during a median follow-up of 13.6 years. In the fully adjusted model, compared with individuals in the lowest tertile of plasma caspase-1 levels, the highest tertile was significantly associated with an increased risk of CVD (HR = 1.11, 95 % CI, 1.04-1.19). Per one-unit Normalized Protein eXpression (NPX) increment in plasma caspase-1 concentrations was associated with a 6 % higher risk of CVD (p＜0.001). The mediating effect of Mets was the largest, at 17.5 %, with its components hypertension, central obesity, hypertriglyceridemia, hyperglycemia and dyslipidemia mediated the effects by 13.52 %, 9.72 %, 7.35 %, 4.63 % and 2.74 %, respectively.

CONCLUSIONS

Higher plasma caspase-1 levels were associated with a higher risk of CVD. This association may be partially mediated by Mets and its components, suggesting that caspase-1 may increase the risk of CVD by increasing the occurrence of Mets.

Exploring Anti-Inflammatory Treatment as Upstream Therapy in the Management of Atrial Fibrillation

Inflammation has been widely recognized as one of the major pathophysiological drivers of the development of atrial fibrillation (AF), which works in tandem with other risk factors of AF including obesity, diabetes, hypertension, and heart failure (HF). Our current understanding of the role of inflammation in the natural history of AF remains elusive; however, several key players, including the NLRP3 (NLR family pyrin domain containing 3) inflammasome, have been acknowledged to be heavily influential on chronic inflammation in the atrial myocardium, which leads to fibrosis and eventual degradation of its electrical function. Nevertheless, our current methods of pharmacological modalities with reported immunomodulatory properties, including well-established classes of drugs e.g., drugs targeting the renin-angiotensin-aldosterone system (RAAS), statins, and vitamin D, have proven effective in reducing the overall risk of developing AF, the onset of postoperative atrial fibrillation (POAF), and reducing overall mortality among patients with AF. This might bring hope for further progress in developing new treatment modalities targeting cellular checkpoints of the NLRP3 inflammasome pathway, or revisiting other well-known anti-inflammatory drugs e.g., colchicine, vitamin C, nonsteroidal anti-inflammatory drugs (NSAIDs), glucocorticosteroids, and antimalarial drugs. In our review, we aim to find relevant upstream anti-inflammatory treatment methods for the management of AF and present the most current real-world evidence of their clinical utility.

Association of elevated albumin-corrected anion gap with all-cause mortality risk in atrial fibrillation: a retrospective study

BACKGROUND

Compared to the conventional anion gap, the albumin-corrected anion gap (ACAG) offers a more precise measure of acid-base imbalance, providing superior prognostic insight. However, the prognostic relevance of ACAG in individuals of atrial fibrillation (AF) remains insufficiently explored. This research seeks to evaluate the correlation between ACAG levels and mortality risk in individuals with AF.

METHODS

We identified individuals diagnosed with AF from the Medical Information Mart for Intensive Care (MIMIC)-IV database. Participants were categorized into quartiles based on their ACAG levels. The outcomes included 30 days and 365 days all-cause mortality. Kaplan-Meier survival curves were utilized to evaluate cumulative survival across the ACAG quartiles. We applied Cox regression and restricted cubic spline regression analyses to evaluate the correlation between ACAG levels and prognosis. Subgroup analyses and interaction assessments were applied to confirm the robustness of the findings.

RESULTS

A total of 2920 AF patients (54.93% male) were incorporated into the analysis, with 1.61% identified as having paroxysmal AF. The 30-day and 365-day mortality rates were 22.91% and 39.21%, respectively. Kaplan-Meier survival curves demonstrated that elevated ACAG levels were significantly linked to increased mortality (log-rank P < 0.001). In multivariate Cox proportional hazards analyses, increased ACAG independently predicted mortality at both 30 days (adjusted hazard ratio [aHR], 1.04; 95% CI, 1.02-1.05; P < 0.01) and 365 days (aHR, 1.03; 95% CI, 1.02-1.05; P < 0.01) after adjusting for potential confounders. A positive relationship between rising ACAG levels and mortality risk was showed by restricted cubic spline analysis. Subgroup analyses revealed no significant interactions (all interaction P-values > 0.05).

CONCLUSIONS

In individuals with AF, higher ACAG levels are related to a greater mortality risk at 30 and 365 days. These findings suggest that ACAG may serve as a valuable prognostic marker for AF patient stratification. Incorporating ACAG into clinical decision-making could support improved therapeutic strategies and enhance patient outcomes.

Prediction Model for POstoperative atriaL fibrillAtion in caRdIac Surgery: The POLARIS Score

Background: New-onset postoperative atrial fibrillation (POAF) is the most common complication after cardiac surgery, occurring approximately in one-third of the patients. This study considered all-comer patients who underwent cardiac surgery to build a predictive model for POAF. Methods: A total of 3467 (Center 1) consecutive patients were used as a derivation cohort to build the model. The POLARIS score was then derived proportionally from the odds ratios obtained following multivariable logistic regression (MLR). The Brier Score, the area under the receiver operating characteristic curve, and the Hosmer-Lemeshow goodness-of-fit test were used to validate the model. Then, 2272 (Center 2) consecutive patients were used as an external validation cohort. Results: In the overall population (n = 5739), POAF occurred in 32.7% of patients. MLR performed in the derivation cohort showed that age, obesity, chronic renal failure, pulmonary hypertension, minimally invasive surgery, and aortic and mitral valve surgery were predictors of POAF. The derived POLARIS score was used to further stratify the population into four risk clusters: low (1.5-3), intermediate (3.5-5), high (5.5-7), and very high (7.5-9), each progressively showing an increase in POAF incidence. This was confirmed in a correlation analysis (Spearman's rho: 0.636). Conclusions: The POLARIS score is a simple-to-use tool to stratify patients at higher risk of POAF. Precise identification of such patients might be used to implement clinical practice with the introduction of preoperative antiarrhythmic prophylaxis, further reducing the incidence of POAF and, potentially, its clinical sequelae, despite further investigations being warranted to test this model in prospective studies.

New Insights into the Role of Inflammatory Pathways and Immune Cell Infiltration in Sleep Deprivation-Induced Atrial Fibrillation: An Integrated Bioinformatics and Experimental Study

Background

The common occurrence of atrial fibrillation (AF) as a cardiac arrhythmia, along with its link to sleep deprivation (SD), is gaining more acknowledgment. Even with progress in comprehending the development of AF, the molecular connections between SD and AF are still not well-defined. The objective of this research was to pinpoint the shared molecular routes responsible for SD-induced AF and investigate possible treatment targets.

Methods

Utilizing bioinformatics, we examined two transcriptome datasets from the Gene Expression Omnibus (GEO) database to pinpoint genes with differential expression (DEGs) common to SD and AF. Analyses focusing on functional enrichment, such as Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), were conducted to pinpoint crucial biological mechanisms and pathways. Furthermore, we utilized immunofluorescence and Western blot techniques to evaluate YBX1 expression and its role in activating NLRP3 inflammasomes in a rat model induced by SD.

Results

A total of 540 common DEGs were precisely identified between the AF and SD data collections. Studies emphasizing functional enrichment have highlighted the significance of inflammation pathways, particularly the NOD-like receptor signaling route. The application of machine learning uncovered four crucial genes-CDC5L, MAPK14, RAB5A, and YBX1-with YBX1 becoming the predominant gene in diagnostic processes. Investigating immune penetration revealed significant connections between YBX1 expression and specific immune cell types, notably CD8+ T cells and M1 macrophages. Live studies have demonstrated that SD amplifies the atrial electrical rearrangement, structural changes, the infiltration of inflammatory cells, and the heightened presence of YBX1 along with inflammasome elements.

Conclusion

The research pinpoints YBX1 as a crucial gene in SD-related AF, possibly influencing its impact via the NOD-like receptor signaling route and the invasion of immune cells. The results offer crucial understanding of the molecular processes behind AF and propose YBX1 as a possible treatment focus to reduce the risk of AF caused by SD.

Genetic and Molecular Underpinnings of Atrial Fibrillation

Atrial fibrillation (AF), the most common sustained arrhythmia, increases stroke and heart failure risks. Here we review genes linked to AF and mechanisms by which they alter AF risk. We highlight gene expression differences between atrial and ventricular cardiomyocytes, regulatory mechanisms responsible for these differences, and their potential contribution to AF. Understanding AF mechanisms through the lens of atrial gene regulation is crucial to improving AF treatment.

Human heart assembloids with autologous tissue-resident macrophages recreate physiological immuno-cardiac interactions

Interactions between the developing heart and the embryonic immune system are essential for proper cardiac development and maintaining homeostasis, with disruptions linked to various diseases. While human pluripotent stem cell (hPSC)-derived organoids are valuable models for studying human organ function, they often lack critical tissue-resident immune cells. Here, we introduce an advanced human heart assembloid model, termed hHMA (human heart-macrophage assembloid), which fully integrates autologous cardiac tissue- resident macrophages (MPs) with pre-existing human heart organoids (hHOs). Through multi-omic analyses, we confirmed that these MPs are phenotypically similar to embryonic cardiac tissue-resident MPs and remain viable in the assembloids over time. The inclusion of MPs significantly impacts hHMA development, influencing cardiac cellular composition, boosting cellular communication, remodeling the extracellular matrix, promoting ventricular morphogenesis, and enhancing sarcomeric maturation. Our findings indicate that MPs contribute to homeostasis via efferocytosis, integrate into the cardiomyocyte electrical system, and support catabolic metabolism. To demonstrate the versatility of this model, we developed a platform to study cardiac arrhythmias by chronic exposure to pro-inflammatory factors linked to arrhythmogenesis in clinical settings, successfully replicating key features of inflammasome-mediated atrial fibrillation. Overall, this work introduces a robust platform for examining the role of immune cells in cardiac development, disease mechanisms, and drug discovery, bridging the gap between in vitro models and human physiology. These findings offer insights into cardiogenesis and inflammation-driven heart disease, positioning the hHMA system as an invaluable tool for future cardiovascular research and therapeutic development.

Arrhythmias Following Patent Foramen Ovale Closure: An Unsolved Enigma

Patent foramen ovale (PFO) closure has proven to be an effective method of reducing the risk of recurrent stroke in patients with embolic stroke of unknown origin (ESUS). One of the most recognized post-procedural complications is the de novo occurrence of supraventricular arrhythmias, mainly atrial fibrillation, in the first three months following PFO closure. Earlier studies reported the incidence to be around 3.4-7%; however, this percentage has risen in recent studies up to 21%. The pathogenesis behind this type of arrhythmia is complex and not clearly understood, although it seems that direct effects of the device on the atria, as well as an inflammatory response, are the two most prevalent mechanisms. Management of this complication might be challenging given the heterogenicity of patient characteristics, so an individualized approach is most wisely followed. This review aims to present the current data on the incidence, pathogenesis and therapeutic strategies behind this rather common concern in an era of increasing transcatheter interventions for PFO.

Targeting the NLRP3 inflammasome signalling for the management of atrial fibrillation

Inflammatory signalling via the nod-like receptor (NLR) family pyrin domain-containing protein-3 (NLRP3) inflammasome has recently been implicated in the pathophysiology of atrial fibrillation (AF). However, the precise role of the NLRP3 inflammasome in various cardiac cell types is poorly understood. Targeting components or products of the inflammasome and preventing their proinflammatory consequences may constitute novel therapeutic treatment strategies for AF. In this review, we summarise the current understanding of the role of the inflammasome in AF pathogenesis. We first review the NLRP3 inflammasome pathway and inflammatory signalling in cardiomyocytes, (myo)fibroblasts and immune cells, such as neutrophils, macrophages and monocytes. Because numerous compounds targeting NLRP3 signalling are currently in preclinical development, or undergoing clinical evaluation for other indications than AF, we subsequently review known therapeutics, such as colchicine and canakinumab, targeting the NLRP3 inflammasome and evaluate their potential for treating AF.

Inhibition of TREM-1 ameliorates angiotensin II-induced atrial fibrillation by attenuating macrophage infiltration and inflammation through the PI3K/AKT/FoxO3a signaling pathway

Inflammation and infiltration of immune cells are intricately linked to the pathogenesis of atrial fibrillation (AF). Triggering receptor expressed on myeloid cells-1 (TREM-1), an enhancer of inflammation, is implicated in various cardiovascular disorders. However, the precise role and potential mechanisms of TREM-1 in the development of AF remain ambiguous. Atrial samples from patients with AF were used to assess the expression levels of TREM-1. An angiotensin II (Ang II)-induced AF mouse model was established to assess the functionality of TREM-1. Cardiac function and AF inducibility were assessed through echocardiography, programmed transvenous cardiac pacing, and atrial electrophysiological mapping. Peripheral blood and atrial inflammatory cells were assessed using flow cytometry. Using histology, bulk RNA sequencing, biochemical analyses, and cell cultures, the mechanistic role of TREM-1 in AF was elucidated. TREM-1 expression was upregulated and co-localized with macrophages in the atria of patients with AF. Pharmacological inhibition of TREM-1 decreased Ang II-induced atrial enlargement and electrical remodeling. TREM-1 inhibition also ameliorated Ang II-induced NLRP3 inflammasome activation, inflammatory factor release, atrial fibrosis, and macrophage infiltration. Transcriptomic analysis revealed that TREM-1 modulates Ang II-induced inflammation through the PI3K/AKT/FoxO3a signaling pathway. In vitro studies further supported these findings, demonstrating that TREM-1 activation exacerbates Ang II-induced inflammation, while overexpression of FoxO3a counteracts this effect. This study discovered the critical role of TREM-1 in the pathogenesis of AF and its underlying molecular mechanisms. Inhibition of TREM-1 provides a new therapeutic strategy for the treatment of AF.

Impeding Nucleotide-Binding Oligomerization Domain-Like Receptor 3 Inflammasome Ameliorates Cardiac Remodeling and Dysfunction in Obesity-Associated Cardiomyopathy

BACKGROUND

Inflammation and metabolic disturbances are key culprits in the pathogenesis of obesity-associated cardiomyopathy. The NLRP3 (nucleotide-binding oligomerization domain-like receptor 3) inflammasome mediates the release of the proinflammatory cytokines IL-1β (interleukin-1β) and IL-18 by activating caspase-1, which is strongly implicated in metabolic disturbances. We here sought to determine whether NLRP3 inflammasome inhibition could ameliorate obesity cardiomyopathy and if so, to further explore its underlying mechanisms.

METHODS AND RESULTS

Male mice were fed a high-fat diet for 24 weeks to induce obesity cardiomyopathy. MCC950 was used to inhibit NLRP3 inflammasome activation. Recombinant adeno-associated virus serotype 9 encoding TXNIP (thioredoxin-interacting protein) under cTnT (cardiac troponin T) promoter and the mitochondrial-targeted antioxidant MitoTEMPO were injected into obese mice to investigate the specific mechanism. To mimic obesity cardiomyopathy in vitro, neonatal rat ventricular myocytes transfected with the small interfering RNA against TXNIP were incubated with 400 μmol palmitic acid for 24 hours. NLRP3 inflammasome was significantly increased in obese hearts. NLRP3 inflammasome inhibition by NLRP3 deletion or MCC950 prevented obesity-induced cardiac systolic and diastolic dysfunction, myocardial hypertrophy and fibrosis, and excessive lipid accumulation in male mice. Conversely, TXNIP overexpression worsened obesity-associated cardiomyopathy. Similarly, MCC950 treatment or TXNIP knockdown reduced palmitic acid-induced NLRP3 inflammasome activation and lipid storage. Mechanistically, abnormal NF-κB (nuclear factor kappa B) pathway activation, increased mitochondrial reactive oxygen species, and elevated TXNIP levels led to excessive NLRP3 inflammasome activation.

CONCLUSIONS

Our study confirms that aberrant NLRP3 inflammasome activation in cardiomyocytes worsens obesity-associated cardiomyopathy and implicates inhibition of NLRP3 inflammasome as a potent therapeutic approach for obesity cardiomyopathy.

Atrial Fibrillation in Heart Failure: Novel Insights, Challenges, and Treatment Opportunities

PURPOSE OF REVIEW

Atrial fibrillation and heart failure frequently co-exist. This review discusses the comorbidity of atrial fibrillation and heart failure, the bi-directional link between them, and the recent advances in the management of these co-existing diseases.

RECENT FINDINGS

Catheter ablation received a class 1 A recommendation for patients with AF and HF, after overwhelming evidence in heart failure with reduced ejection fraction and end-stage heart failure, while clinical trials are still lacking in patients with preserved ejection. Guideline-medical therapy of heart failure decreases the incidence of atrial fibrillation and the progression of atrial myopathy. Based on the current evidence, management of patients with both HF and AF should be include early optimization of comorbidity control, guideline-medical therapy for heart failure, and rhythm control preferentially through catheter ablation in properly selected patients.

Comparison of the Cecum Ligation and Puncture Method and the Intraperitoneal Lipopolysaccharide Injection Method for the Construction of a New-Onset Atrial Fibrillation Model of Sepsis

Background

New-onset atrial fibrillation (AF) in sepsis significantly impacted patient morbidity and mortality, yet the optimal animal model for studying this condition remains undetermined. This study aimed to establish a stable animal model for new-onset AF in sepsis and to explore the molecular mechanisms involved.

Methods

Forty-seven Sprague-Dawley rats were utilized, with the cecal ligation and puncture (CLP) group divided into 0.6 mm and 1.0 mm needle outer diameter subgroups, and the lipopolysaccharide (LPS) group into 5 mg/kg, 10 mg/kg, 15 mg/kg, and 20 mg/kg dosage subgroups. The incidence of new-onset AF and five-day mortality rates were compared to identify the most stable modeling conditions. Selected subgroups underwent further analysis, including cardiac ultrasound, electrophysiology, and pathological examinations. Inflammation-related molecular levels in the atrium were assessed using ELISA and Western blotting (WB).

Results

The intraperitoneal injection of 10 mg/kg LPS was identified as the most stable model for new-onset AF in sepsis, with significant findings including increased left atrial area and fibrosis, left ventricular pump dysfunction, uncoordinated ventricular wall motion, and impaired electrical impulse conduction. The effective atrial refractory period was markedly shorter, and susceptibility to AF was higher in the LPS group compared to the CLP group. Molecular analysis revealed elevated levels of NOD-like receptor protein 3(NLRP3) inflammasomes, apoptosis-associated speck-like protein containing a CARD(ASC), Caspase-1 p20 Elevated levels of three inflammation-related proteins and increased activity of the Sphingosine 1-phosphate/Sphingosine 1-phosphate Receptor 2(S1P/S1P2) signaling axis.

Conclusion

Intraperitoneal injection of 10 mg/kg of LPS can successfully construct a new-onset AF model in sepsis, and NLRP3 inflammatory vesicles mediated by the S1P/S1P2 signaling axis may promote new-onset AF in sepsis.

Role of NLRP3 Inflammasome in Heart Failure Patients Undergoing Cardiac Surgery as a Potential Determinant of Postoperative Atrial Fibrillation and Remodeling: Is SGLT2 Cotransporter Inhibition an Alternative for Cardioprotection?

In heart failure (HF) patients undergoing cardiac surgery, an increased activity of mechanisms related to cardiac remodeling may determine a higher risk of postoperative atrial fibrillation (POAF). Given that atrial fibrillation (AF) has a negative impact on the course and management of HF, including the need for anticoagulation therapy, identifying the factors associated with AF occurrence after cardiac surgery is crucial for the prognosis of these patients. POAF is thought to occur when various clinical and biochemical triggers act on susceptible cardiac tissue (first hit), with oxidative stress and inflammation during cardiopulmonary bypass (CPB) surgery being potential contributing factors (second hit). However, the molecular mechanisms involved in these processes remain poorly characterized. Recent research has shown that patients who later develop POAF often have pre-existing abnormalities in calcium handling and activation of NLRP3-inflammasome signaling in their atrial cardiomyocytes. These molecular changes may make cardiomyocytes more susceptible to spontaneous Ca2+-releases and subsequent arrhythmias, particularly when exposed to inflammatory mediators. Additionally, some clinical studies have linked POAF with elevated preoperative inflammatory markers, but there is a need for further research in order to better understand the impact of CPB surgery on local and systemic inflammation. This knowledge would make it possible to determine whether patients susceptible to POAF have pre-existing inflammatory conditions or cellular electrophysiological factors that make them more prone to developing AF and cardiac remodeling. In this context, the NLRP3 inflammasome, expressed in cardiomyocytes and cardiac fibroblasts, has been identified as playing a key role in the development of HF and AF, making patients with pre-existing HF with reduced ejection fraction (HFrEF) the focus of several clinical studies with interventions that act at this level. On the other hand, HFpEF has been linked to metabolic and non-ischemic risk factors, but more research is needed to better characterize the myocardial remodeling events associated with HFpEF. Therefore, since ventricular remodeling may differ between HFrEF and HFpEF, it is necessary to perform studies in both groups of patients due to their pathophysiological variations. Clinical evidence has shown that pharmacological therapies that are effective for HFrEF may not provide the same anti-remodeling benefits in HFpEF patients, particularly compared to traditional adrenergic and renin-angiotensin-aldosterone system inhibitors. On the other hand, there is growing interest in medications with pleiotropic or antioxidant/anti-inflammatory effects, such as sodium-glucose cotransporter 2 inhibitors (SGLT-2is). These drugs may offer anti-remodeling effects in both HFrEF and HFpEF by inhibiting pro-inflammatory, pro-oxidant, and NLRP3 signaling pathways and their mediators. The anti-inflammatory, antioxidant, and anti-remodeling effects of SGLT-2 i have progressively expanded from HFrEF and HFpEF to other forms of cardiac remodeling. However, these advances in research have not yet encompassed POAF despite its associations with inflammation, oxidative stress, and remodeling. Currently, the direct or indirect effects of NLRP3-dependent pathway inhibition on the occurrence of POAF have not been clinically assessed. However, given that NLRP3 pathway inhibition may also indirectly affect other pathways, such as inhibition of NF-kappaB or inhibition of matrix synthesis, which are strongly linked to POAF and cardiac remodeling, it is reasonable to hypothesize that this type of intervention could play a role in preventing these events.

Drug-Loaded Mesoporous Polydopamine Nanoparticles in Chitosan Hydrogels Enable Myocardial Infarction Repair through ROS Scavenging and Inhibition of Apoptosis

In this study, we synthesized mesoporous polydopamine nanoparticles (MPDA NPs) using an emulsion-induced interface assembly strategy and loaded epigallocatechin gallate (EGCG) into MPDA NPs via electrostatic attraction to form EGCG@MPDA NPs. In the post myocardial infarction (MI) environment, these interventions specifically aimed to eliminate reactive oxygen species (ROS) and facilitate the repair of MI. We further combined them with a thermosensitive chitosan (CS) hydrogel to construct an injectable composite hydrogel (EGCG@MPDA/CS hydrogel). Utilizing in vitro experiments, the EGCG@MPDA/CS hydrogel exhibited excellent ROS-scavenging ability of H9C2 cells under the oxidative stress environment and also could inhibit their apoptosis. The EGCG@MPDA/CS hydrogel significantly promoted left ventricular ejection fraction (LVEF) in infarcted rat models post injection for 28 days compared to the PBS group (51.25 ± 1.73% vs 29.31 ± 0.78%, P < 0.05). In comparison to the PBS group, histological analysis revealed a substantial increase in left ventricular (LV) wall thickness in the EGCG@MPDA/CS hydrogel group (from 0.58 ± 0.03 to 1.39 ± 1.11 mm, P < 0.05). This work presents a novel approach to enhance MI repair by employing the EGCG@MPDA/CS hydrogel. This hydrogel effectively reduces local oxidative stress by ROS and stimulates the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway.

Noise Exposure in the Workplace, Genetic Susceptibility, and Incidence of Atrial Fibrillation: A Prospective Cohort Study

BACKGROUND

No study explored the association of noise exposure in the workplace and genetic susceptibility with incidence of atrial fibrillation (AF). We aimed to assess the separate and joint relationship of noise exposure in the workplace and genetic susceptibility with the risk of AF.

METHODS AND RESULTS

We included 167 577 participants without AF at baseline in UK Biobank. Cox proportional hazards models were used to assess the separate and joint association of noise exposure in the workplace and genetic susceptibility with the risk of AF. During a median follow-up of 11.83 years, we observed 9355 AF cases. Compared with no noise exposure in the workplace, the hazard ratios (HRs) and were 1.08 (95% CI, 0.99-1.18) for noise exposure in the workplace of <1 year, 1.03 (95% CI, 0.95-1.12) for noise exposure in the workplace of around 1 to 5 years, and 1.08 (95% CI, 1.02-1.14) for noise exposure in the workplace of >5 years, respectively, after adjusting for potential confounders. Genetic risk was positively associated with AF, compared with low genetic risk (tertile 1), the HRs were 1.50 (95% CI, 1.41-1.59) for medium genetic risk (tertile 2) and 2.51 (95% CI, 2.38-2.65) for high genetic risk (tertile 3). However, no interaction between noise exposure in the workplace and genetic susceptibility was observed (P>0.05).

CONCLUSIONS

Long-term noise exposure in the workplace is positively associated with a higher incidence of AF regardless of genetic background.

Gene therapy for atrial fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia in adults. Current limitations of pharmacological and ablative therapies motivate the development of novel therapies as next generation treatments for AF. The arrhythmia mechanisms creating and sustaining AF are key elements in the development of this novel treatment. Gene therapy provides a useful platform that allows us to regulate the mechanisms of interest using a suitable transgene(s), vector, and delivery method. Effective gene therapy strategies in the literature have targeted maladaptive electrical or structural remodeling that increase vulnerability to AF. In this review, we will summarize key elements of gene therapy for AF, including molecular targets, gene transfer vectors, atrial gene delivery and preclinical efficacy and toxicity testing. Recent advances and challenges in the field will be also discussed.

CHA2DS2-VASc Score as Predictor of New-Onset Atrial Fibrillation and Mortality in Critical COVID-19 Patients

BACKGROUND

Pre-existing and new-onset atrial fibrillation (NOAF) is a common arrhythmia in COVID-19 patients and is related to increased mortality. CHA2DS2-VASc score was initially developed to evaluate thromboembolic risk in patients with AF. Moreover, it predicted adverse outcomes in other clinical conditions, including SARS-CoV-2 infection. We aimed to evaluate the association of CHA2DS2-VASc with NOAF, ICU length of stay (LOS) and mortality in critically ill COVID-19 patients. We also examined the relationship of NOAF with mortality. We reviewed the literature to describe the link between cardiovascular risk factors and inflammatory response of severe COVID-19.

METHODS AND RESULTS

We retrospectively studied 163 COVID-19 patients admitted to a level 3 general ICU from March 2020 to April 2022. Patients were of advanced age (median 64 years, IQR 56.5-71) and the majority of them were male (67.5%). Regarding NOAF, we excluded 12 patients with AF history. In this group, CHA2DS2VASc score was significantly elevated (3 IQR (1-4) versus 1 IQR (1-2.75), p = 0.003). Specifically, three components of CHA2DS2VASc were notably increased: age (p < 0.001), arterial hypertension (p = 0.042) and stroke (p = 0.047). ICU mortality was raised in the NOAF group [75.8% versus 34.8%, p < 0.001 OR 5.87, 95% CI (2.43, 14.17)]. This was significant even after adjusting for ICU clinical scores (APACHE II and SOFA). About mortality in the entire sample, survivors were younger (p = 0.001). Non-survivors had greater APACHE II (p = 0.04) and SOFA (p = 0.033) scores. CHA2DS2VASc score was positively associated with mortality [p = 0.031, OR 1.28, 95% CI (1.03, 1.6)]. ICU length of stay was associated with mortality (p = 0.016) but not with CHA2DS2VASc score (p = 0.842).

CONCLUSIONS

NOAF and CHA2DS2VASc score were associated with higher mortality in COVID-19 ICU patients. CHA2DS2VASc score was also associated with NOAF but not with ICU LOS.

Molecular mechanisms involved in therapeutic effects of natural compounds against cisplatin-induced cardiotoxicity: a review

Cisplatin is a widely used chemotherapeutic agent for the treatment of various cancers. However, the clinical use of cisplatin is limited by its cardiotoxic side effects. The primary mechanisms implicated in this cardiotoxicity include mitochondrial dysfunction, oxidative stress, inflammation, and apoptotic. Numerous natural compounds (NCs) have been introduced as promising protective factors against cisplatin-mediated cardiac damage. The current review summarized the potential of various NCs as cardioprotective agents at the molecular levels. These compounds exhibited potent antioxidant and anti-inflammatory effects by interaction with the PI3K/AKT, AMPK, Nrf2, NF-κB, and NLRP3/caspase-1/GSDMD pathways. Generally, the modulation of these signaling pathways by NCs represents a promising strategy for improving the therapeutic index of cisplatin by reducing its cardiac side effects.

Rectifying METTL4-Mediated N6-Methyladenine Excess in Mitochondrial DNA Alleviates Heart Failure

BACKGROUND

Myocardial mitochondrial dysfunction underpins the pathogenesis of heart failure (HF), yet therapeutic options to restore myocardial mitochondrial function are scarce. Epigenetic modifications of mitochondrial DNA (mtDNA), such as methylation, play a pivotal role in modulating mitochondrial homeostasis. However, their involvement in HF remains unclear.

METHODS

Experimental HF models were established through continuous angiotensin II and phenylephrine (AngII/PE) infusion or prolonged myocardial ischemia/reperfusion injury. The landscape of N6-methyladenine (6mA) methylation within failing cardiomyocyte mtDNA was characterized using high-resolution mass spectrometry and methylated DNA immunoprecipitation sequencing. A tamoxifen-inducible cardiomyocyte-specific Mettl4 knockout mouse model and adeno-associated virus vectors designed for cardiomyocyte-targeted manipulation of METTL4 (methyltransferase-like protein 4) expression were used to ascertain the role of mtDNA 6mA and its methyltransferase METTL4 in HF.

RESULTS

METTL4 was predominantly localized within adult cardiomyocyte mitochondria. 6mA modifications were significantly more abundant in mtDNA than in nuclear DNA. Postnatal cardiomyocyte maturation presented with a reduction in 6mA levels within mtDNA, coinciding with a decrease in METTL4 expression. However, an increase in both mtDNA 6mA level and METTL4 expression was observed in failing adult cardiomyocytes, suggesting a shift toward a neonatal-like state. METTL4 preferentially targeted mtDNA promoter regions, which resulted in interference with transcription initiation complex assembly, mtDNA transcriptional stalling, and ultimately mitochondrial dysfunction. Amplifying cardiomyocyte mtDNA 6mA through METTL4 overexpression led to spontaneous mitochondrial dysfunction and HF phenotypes. The transcription factor p53 was identified as a direct regulator of METTL4 transcription in response to HF-provoking stress, thereby revealing a stress-responsive mechanism that controls METTL4 expression and mtDNA 6mA. Cardiomyocyte-specific deletion of the Mettl4 gene eliminated mtDNA 6mA excess, preserved mitochondrial function, and mitigated the development of HF upon continuous infusion of AngII/PE. In addition, specific silencing of METTL4 in cardiomyocytes restored mitochondrial function and offered therapeutic relief in mice with preexisting HF, irrespective of whether the condition was induced by AngII/PE infusion or myocardial ischemia/reperfusion injury.

CONCLUSIONS

Our findings identify a pivotal role of cardiomyocyte mtDNA 6mA and the corresponding methyltransferase, METTL4, in the pathogenesis of mitochondrial dysfunction and HF. Targeted suppression of METTL4 to rectify mtDNA 6mA excess emerges as a promising strategy for developing mitochondria-focused HF interventions.

CALCOCO2 prevents AngII-induced atrial remodeling by regulating the interaction between mitophagy and mitochondrial stress

BACKGROUND

The biological functions of mitochondrial complexes are closely related to the development of atrial fibrillation (AF). Calcium binding and coiled-coil domain 2 (CALCOCO2) is a novel and specific receptor for mitophagy; however, its function in AF remains unknown. Therefore, this study aimed to investigate the role and molecular mechanisms of CALCOCO2 in AF, especially its regulatory mechanism in mitophagy and mitochondrial stress.

METHODS

Mice and HL-1 cells were treated with AngII to establish in vitro and in vivo AF models. Additionally, we examined the effect of CALCOCO2 or DAP3 Binding Cell Death Enhancer 1 (DELE1) overexpression on mitophagy and mitochondrial stress in AF models. To investigate the role of mitophagy in the regulatory effects of CALCOCO2 in AF, HL-1 cells were treated with chloroquine, a mitophagy inhibitor. Moreover, mitochondrial parameters were examined using specific fluorescent probes, transmission electron microscopy, western blotting, immunohistochemistry, and confocal microscopy.

RESULTS

AngII severely impaired the normal morphology and function of mitochondria; inhibited mitophagy; promoted atrial mitochondrial stress, fibrosis, and oxidative stress; and accelerated the progression of atrial remodeling in atrial myocytes. However, CALCOCO2 overexpression reversed/ameliorated these AF-induced changes. Additionally, CALCOCO2 overexpression restored mitochondrial homeostasis in atrial muscle by activating mitophagy and ameliorating mitochondrial stress. Mechanistically, DELE1 overexpression increased mitochondrial reactive oxygen species level and the expression of mitochondrial stress proteins (HRI, eIF2α, and ATF4) even in CALCOCO2-expressing in vitro AF models..

CONCLUSIONS

CALCOCO2 may serve as a potential target for AF therapy to prevent or reverse the progression of atrial remodeling by regulating mitophagy and DELE1-mediated mitochondrial stress.

Identification of the optimal reference genes for atrial fibrillation model established by iPSC-derived atrial myocytes

BACKGROUND

Atrial fibrillation (AF) stands as a prevalent and detrimental arrhythmic disorder, characterized by intricate pathophysiological mechanisms. The availability of reliable and reproducible AF models is pivotal in unraveling the underlying mechanisms of this complex condition. Unfortunately, the researchers are still confronted with the absence of consistent in vitro AF models, hindering progress in this crucial area of research.

METHODS

Human induced pluripotent stem cells derived atrial myocytes (hiPSC-AMs) were generated based on the GiWi methods and were verified by whole-cell patch clamp, immunofluorescent staining, and flow cytometry. Then hiPSC-AMs were employed to establish the AF model by HS. Whole-cell patch clamp technique and calcium imaging were used to identify the AF model. The stability of 29 reference genes was evaluated using delta-Ct, GeNorm, NormFinder, and BestKeeper algorithms; RESULTS: HiPSC-AMs displayed atrial myocyte action potentials and expressed the atrial-specific protein MLC-2 A and NR2F2, about 70% of the cardiomyocytes were MLC-2 A positive. After HS, hiPSC-AMs showed a significant increase in beating frequency, a shortened action potential duration, and increased calcium transient frequency. Of the 29 candidate genes, the top five most stably ranked genes were ABL1, RPL37A, POP4, RPL30, and EIF2B1. After normalization using ABL1, KCNJ2 was significantly upregulated in the AF model; Conclusions: In the hiPSC-AMs AF model established by HS, ABL1 provides greater normalization efficiency than commonly used GAPDH.

[Pathogenesis and potential diagnostic biomarkers of atrial fibrillation in Chinese population: a study based on bioinfor-matics]

OBJECTIVES

To explore the pathogenesis and potential biomarkers of atrial fibrillation based on bioinformatics.

METHODS

Differentially expressed genes and module genes related to atrial fibrillation were obtained from GSE41177 and GSE79768 datasets (Chinese-origin tissue samples) through differential expression analysis and weighted gene co-expression network analysis. Candidate hub genes were obtained by taking intersections, and hub genes were obtained after gender stratification. Subsequently, functional enrichment analysis and immune infiltration analysis were performed. Four machine learning models were constructed based on the hub genes, and the optimal model was selected to construct a prediction nomogram. The prediction ability of the nomogram was verified using calibration curves and decision curves. Finally, potential therapeutic drugs for atrial fibrillation were screened from the DGIdb database.

RESULTS

A total of 67 differentially expressed genes and 65 module genes related to atrial fibrillation were identified. Functional enrichment analysis indicated that the pathogenesis of atrial fibrillation was closely related to inflammatory response, immune response, and immune and infectious diseases. Four common hub genes (TYROBP, FCER1G, EVI2B and SOD2), and two genes specifically expressed in male (PILRA and SLC35G3) and female (HLA-DRA and GATP) patients with atrial fibrillation were obtained after gender-segregated screening. The extreme gradient boosting model had satisfactory diagnostic efficiency, and the nomogram constructed based on the hub genes, male significant variables (PILRA, SLC35G3 and SOD2), and female significant variables (FCER1G, SOD2 and TYROBP) had satisfactory predictive ability. Immune infiltration analysis demonstrated a disturbed immune infiltration microenvironment in atrial fibrillation with a higher abundance of plasma cells, neutrophils, and γδT cells, with a higher abundance of neutrophils in males and resting mast cells in females. Two potential drugs for the treatment of atrial fibrillation, valproic acid and methotrexate, were obtained by database and literature screening.

CONCLUSIONS

The pathogenesis of atrial fibrillation is closely related to inflammation and immune response, and the microenvironment of immune cell infiltration of cardiomyocytes in the atrial tissue of patients with atrial fibrillation is disordered. TYROBP, FCER1G, EVI2B and SOD2 serve as potential diagnostic biomarkers of atrial fibrillation; PILRA and SLC35G3 serve as potential specific diagnostic biomarkers of atrial fibrillation in the male population, which can effectively predict the risk of atrial fibrillation development and are also potential targets for the treatment of atrial fibrillation.

Translation of pathophysiological mechanisms of atrial fibrosis into new diagnostic and therapeutic approaches

Atrial fibrosis is one of the main manifestations of atrial cardiomyopathy, an array of electrical, mechanical and structural alterations associated with atrial fibrillation (AF), stroke and heart failure. Atrial fibrosis can be both a cause and a consequence of AF and, once present, it accelerates the progression of AF. The pathophysiological mechanisms leading to atrial fibrosis are diverse and include stretch-induced activation of fibroblasts, systemic inflammatory processes, activation of coagulation factors and fibrofatty infiltrations. Importantly, atrial fibrosis can occur in different forms, such as reactive and replacement fibrosis. The diversity of atrial fibrosis mechanisms and patterns depends on sex, age and comorbidity profile, hampering the development of therapeutic strategies. In addition, the presence and severity of comorbidities often change over time, potentially causing temporal changes in the mechanisms underlying atrial fibrosis development. This Review summarizes the latest knowledge on the molecular and cellular mechanisms of atrial fibrosis, its association with comorbidities and the sex-related differences. We describe how the various patterns of atrial fibrosis translate into electrophysiological mechanisms that promote AF, and critically appraise the clinical applicability and limitations of diagnostic tools to quantify atrial fibrosis. Finally, we provide an overview of the newest therapeutic interventions under development and discuss relevant knowledge gaps related to the association between clinical manifestations and pathological mechanisms of atrial fibrosis and to the translation of this knowledge to a clinical setting.

The effect of macrophage-cardiomyocyte interactions on cardiovascular diseases and development of potential drugs

The interaction between macrophages and cardiomyocytes plays an important role not only in maintaining cardiac homeostasis, but also in the development of many cardiovascular diseases (CVDs), such as myocardial infarction (MI) and heart failure (HF). In addition to supporting cardiomyocytes, macrophages and cardiomyocytes have a close and complex relationship. By studying their cross-talk, we can better understand novel mechanisms and target pathogenic mechanisms, and improve the treatment of CVDs. We review macrophage-cardiomyocyte communication through connexin 43 (Cx43)-containing gap junctions (GJs) directly, secreted protein factors indirectly, and discuss the implications of these interactions in cardiac homeostasis and the development of various CVDs, including MI, HF, arrhythmia, cardiac fibrosis and myocarditis. In this section, we review various drugs that work by modulating cytokines or other proteins to reduce inflammation in CVDs. The clinical findings from targeting inflammation in CVDs are also discussed. Additionally, we examine the challenges and opportunities for improving our understanding of macrophage-cardiomyocyte coupling as it relates to pathophysiological disease processes, extending our research scope, and helping identify new molecular targets and improve the effectiveness of existing therapies.

Metabolic remodelling in atrial fibrillation: manifestations, mechanisms and clinical implications

Atrial fibrillation (AF) is a continually growing health-care burden that often presents together with metabolic disorders, including diabetes mellitus and obesity. Current treatments often fall short of preventing AF and its adverse outcomes. Accumulating evidence suggests that metabolic disturbances can promote the development of AF through structural and electrophysiological remodelling, but the underlying mechanisms that predispose an individual to AF are aetiology-dependent, thus emphasizing the need for tailored therapeutic strategies to treat AF that target an individual's metabolic profile. AF itself can induce changes in glucose, lipid and ketone metabolism, mitochondrial function and myofibrillar energetics (as part of a process referred to as 'metabolic remodelling'), which can all contribute to atrial dysfunction. In this Review, we discuss our current understanding of AF in the setting of metabolic disorders, as well as changes in atrial metabolism that are relevant to the development of AF. We also describe the potential of available and emerging treatment strategies to target metabolic remodelling in the setting of AF and highlight key questions and challenges that need to be addressed to improve outcomes in these patients.

Early inhibition of the ATM/p53 pathway reduces the susceptibility to atrial fibrillation and atrial remodeling following acute myocardial infarction

Atrial fibrillation (AF) emerges as a critical complication following acute myocardial infarction (AMI) and is associated with a significant increased risk of heart failure, stroke and mortality. Ataxia telangiectasia mutated (ATM), a key player in DNA damage repair (DDR), has been implicated in multiple cardiovascular conditions, however, its involvement in the development of AF following AMI remains unexplored. This study seeks to clarify the contribution of the ATM/p53 pathway in the onset of AF post-AMI and to investigate the underlying mechanisms. The rat model of AMI was established by ligating left anterior descending coronary artery in the presence or absence of Ku55933 (an ATM kinase inhibitor, 5 mg/kg/d) treatment. Rats receiving Ku55933 were further divided into the early administration group (administered on days 1, 2, 4, and 7 post-AMI) and the late administration group (administered on days 8, 9, 11 and 14 post-AMI). RNA-sequencing was performed 14 days post-operation. In vitro, H2O2-challenged HL-1 atrial muscle cells were utilized to evaluate the potential effects of different ATM inhibition schemes, including earlier, middle, and late periods of intervention. Fourteen days post-AMI injury, the animals exhibited significantly increased AF inducibility, exacerbated atrial electrical/structural remodeling, reduced ventricular function and exacerbated atrial DNA damage, as evidenced by enhanced ATM/p53 signaling as well as γH2AX level. These effects were partially consistent with the enrichment results of bioinformatics analysis. Notably, the deleterious effects were ameliorated by early, but not late, administration of Ku55933. Mechanistically, inhibition of ATM signaling successfully suppressed atrial NLRP3 inflammasome-mediated pyroptotic pathway. Additionally, the results were validated in the in vitro experiments demonstrating that early inhibition of Ku55933 not only attenuated cellular ATM/p53 signaling, but also mitigated inflammatory response by reducing NLRP3 activation. Collectively, hyperactivation of ATM/p53 contributed to the pathogenesis of AF following AMI. Early intervention with ATM inhibitors substantially mitigated AF susceptibility and atrial electrical/structural remodeling, highlighting a novel therapeutic avenue against cardiac arrhythmia following AMI.

Aging-associated atrial fibrillation: A comprehensive review focusing on the potential mechanisms

Atrial fibrillation (AF) has been receiving a lot of attention from scientists and clinicians because it is an extremely common clinical condition. Due to its special hemodynamic changes, AF has a high rate of disability and mortality. So far, although AF has some therapeutic means, it is still an incurable disease because of its complex risk factors and pathophysiologic mechanisms, which is a difficult problem for global public health. Age is an important independent risk factor for AF, and the incidence of AF increases with age. To date, there is no comprehensive review on aging-associated AF. In this review, we systematically discuss the pathophysiologic evidence for aging-associated AF, and in particular explore the pathophysiologic mechanisms of mitochondrial dysfunction, telomere attrition, cellular senescence, disabled macroautophagy, and gut dysbiosis involved in recent studies with aging-associated AF. We hope that by exploring the various dimensions of aging-associated AF, we can better understand the specific relationship between age and AF, which may be crucial for innovative treatments of aging-associated AF.

Overview of pyroptosis mechanism and in-depth analysis of cardiomyocyte pyroptosis mediated by NF-κB pathway in heart failure

The pyroptosis of cardiomyocytes has become an essential topic in heart failure research. The abnormal accumulation of these biological factors, including angiotensin II, advanced glycation end products, and various growth factors (such as connective tissue growth factor, vascular endothelial growth factor, transforming growth factor beta, among others), activates the nuclear factor-κB (NF-κB) signaling pathway in cardiovascular diseases, ultimately leading to pyroptosis of cardiomyocytes. Therefore, exploring the underlying molecular biological mechanisms is essential for developing novel drugs and therapeutic strategies. However, our current understanding of the precise regulatory mechanism of this complex signaling pathway in cardiomyocyte pyroptosis is still limited. Given this, this study reviews the milestone discoveries in the field of pyroptosis research since 1986, analyzes in detail the similarities, differences, and interactions between pyroptosis and other cell death modes (such as apoptosis, necroptosis, autophagy, and ferroptosis), and explores the deep connection between pyroptosis and heart failure. At the same time, it depicts in detail the complete pathway of the activation, transmission, and eventual cardiomyocyte pyroptosis of the NF-κB signaling pathway in the process of heart failure. In addition, the study also systematically summarizes various therapeutic approaches that can inhibit NF-κB to reduce cardiomyocyte pyroptosis, including drugs, natural compounds, small molecule inhibitors, gene editing, and other cutting-edge technologies, aiming to provide solid scientific support and new research perspectives for the prevention and treatment of heart failure.

Thrombin receptor PAR4 cross-activates the tyrosine kinase c-met in atrial cardiomyocytes

Thrombin supports coagulation-independent inflammation via protease-activated receptors (PAR). PAR4 is specifically increased in obese human atria, correlating with NLRP3 inflammasome activation. PAR4-mediated NLRP3 inflammasome activation in atrial cardiomyocytes is not known, nor have signaling partners been identified. Thrombin transactivates the hepatocyte growth factor receptor in some cancer cells, so we examined PAR4/c-met cross-talk in atrial cardiomyocytes and its possible significance in obesity. Cardiomyocytes from right atrial appendages (RAA) of obese patients expressed more PAR1 and PAR4 compared to non-obese. In HL-1 atrial cardiomyocytes, thrombin induced caspase-1 auto-activation and IL-1β maturation; IL-1β secretion was evoked by PAR4-activating peptide (AP), but not PAR1-AP. PAR4-AP additionally increased phosphorylated CaMKII-Thr287, mTOR-Ser2481, and Akt-Ser473 while suppressing AMPK-Thr172 phosphorylation. Total kinase levels were largely unaltered. PAR4AP rapidly increased phosphorylated c-met in HL-1 cells and over time also transcriptionally upregulated c-met. The c-met inhibitor SGX-523 abrogated the effects of PAR4-AP on CaMKII/AKT/mTOR phosphorylation but did not affect PAR4-stimulated IL-1β production. Obese human RAA contained more IL-1β, phospho-c-met, and phospho-mTOR than non-obese RAA; CamKII phosphorylation was not modified. Atria from high-fat diet (HFD) versus chow-fed mice also contained more IL-1β, together with higher myeloperoxidase activity, Acta2 mRNA total and phosphorylated c-met; these increases were blunted in PAR4-/- HFD-fed mice. Thrombin cross-activates c-met via PAR4 in atrial cardiomyocytes. Transactivated c-met contributes partially to PAR4-mediated signaling, but NLRP3 inflammasome activation appears to be largely independent of c-met. Abundance of PAR4 and activated c-met increases with obesity, providing therapeutic targets for management of adiposity-driven AF.

Colchicine for the treatment of the spectrum of cardiovascular diseases: current evidence and ongoing perspectives

Colchicine is one of the oldest drugs in medicine. Traditionally used to treat and prevent gouty attacks, it has been introduced into cardiovascular medicine for the treatment and prevention of pericarditis, starting from the positive experience in the treatment and prevention of polyserositis in familial mediterranean fever. Colchicine is a lipophilic drug that enters the cells and is eliminated by glycoprotein P. As granulocytes are lacking in this protein, colchicine is able to concentrate in these cells, exerting a substantial anti-inflammatory action, even with low oral doses. As these cells may trigger acute cardiovascular events, colchicine has been shown to be efficacious and safe to prevent acute coronary syndromes and ischemic stroke with an efficacy comparable to more established treatments, such as antiplatelet agents and statins. On this basis, colchicine seems a promising, efficacious, well tolerated, and cheap option for the prevention of several cardiovascular events, and it may become an additional pillar in the pharmacologic treatment of cardiovascular diseases.

Relationship between sodium-glucose cotransporter 2 inhibitors and atrial fibrillation recurrence after pulmonary vein isolation in patients with type 2 diabetes and persistent atrial fibrillation

BACKGROUND

The impact of sodium-glucose cotransporter 2 (SGLT2) inhibitors on the postoperative recurrence of atrial fibrillation (AF) in patients with persistent AF undergoing an initial radiofrequency ablation is not yet established. The objective of this study is to assess the impact of SGLT2 inhibitors on the recurrence of AF after radiofrequency ablation in patients with type 2 diabetes complicated persistent AF.

METHODS

A total of 182 patients with type 2 diabetes and persistent AF, who underwent their first radiofrequency ablation for AF at our center, were enrolled and divided into two groups: the SGLT2 inhibitor group and the non-SGLT2 inhibitor group. The main outcome of the follow-up was the postoperative recurrence of AF.

RESULTS

A total of 49 participants experienced AF recurrence. The use of SGLT2 inhibitors in patients with type 2 diabetes who underwent AF ablation was associated with a significantly lower risk of AF recurrence (adjusted hazard ratio: 0.65; 95% confidence interval: 0.28-0.83; p < .01).

CONCLUSIONS

The use of SGLT2 inhibitors is associated with a decreased risk of arrhythmia recurrence after AF ablation in patients with type 2 diabetes complicated with persistent AF.

Investigative agents for atrial fibrillation: agonists and stimulants, progress and expectations

INTRODUCTION

Atrial fibrillation (AF) is the most common type of cardiac arrhythmia. Its prevalence has increased due to worldwide populations that are aging in combination with the growing incidence of risk factors associated. Recent advances in our understanding of AF pathophysiology and the identification of nodal players involved in AF-promoting atrial remodeling highlights potential opportunities for new therapeutic approaches.

AREAS COVERED

This detailed review summarizes recent developments in the field antiarrhythmic drugs in the field AF.

EXPERT OPINION

The current situation is far than optimal. Despite clear unmet needs in drug development in the field of AF treatment, the current development of new drugs is absent. The need for a molecule with absence of cardiac and non-cardiac toxicity in the short and long term is a limitation in the field. Improvement in the understanding of AF genetics, pathophysiology, molecular alterations, big data and artificial intelligence with the objective to provide a personalized AF treatment will be the cornerstone of AF treatment in the coming years.

Atrial fibrillation in cancer, anticancer therapies, and underlying mechanisms

Atrial fibrillation (AF) is a common arrhythmic complication in cancer patients and can be exacerbated by traditional cytotoxic and targeted anticancer therapies. Increased incidence of AF in cancer patients is independent of confounding factors, including preexisting myocardial arrhythmogenic substrates, type of cancer, or cancer stage. Mechanistically, AF is characterized by fast unsynchronized atrial contractions with rapid ventricular response, which impairs ventricular filling and results in various symptoms such as fatigue, chest pain, and shortness of breath. Due to increased blood stasis, a consequence of both cancer and AF, concern for stroke increases in this patient population. To compound matters, cardiotoxic anticancer therapies themselves promote AF; thereby exacerbating AF morbidity and mortality in cancer patients. In this review, we examine the relationship between AF, cancer, and cardiotoxic anticancer therapies with a focus on the shared molecular and electrophysiological mechanisms linking these disease processes. We also explore the potential role of sodium-glucose co-transporter 2 inhibitors (SGLT2i) in the management of anticancer-therapy-induced AF.

Modern Instrumental Methods of Diagnostics and Risk Assessment of Developing Antitumor Therapy Cardiovasculotoxicity

The most important component of cardio-oncology is the assessment of the risk of development and diagnosis of cardiovascular toxicity of the antitumor therapy, the detection of which is largely based on visualization of the cardiovascular system. The article addresses up-to-date methods of non-invasive visualization of the heart and blood vessels, according to the 2022 European Society of Cardiology Clinical Guidelines on cardio-oncology. Also, the article discusses promising cardiovascular imaging techniques that are not yet included in the guidelines: assessment of coronary calcium using multislice computed tomography and positron emission computed tomography with 18F-labeled 2-deoxy-2-fluoro-d-glucose.