Biomarkers in Atrial Fibrillation: Pathogenesis and Clinical Implications

Right atrial wall inflammation detected by 18F-FDG PET/CT may be significantly associated with persistent atrial fibrillation: a prospective case-control study

AIM

Atrial fibrillation (AF) is a progressive disease from paroxysmal to persistent, and persistent AF (PerAF) had worse prognosis. AF has potential link with inflammation, but it is not clear whether PerAF or paroxysmal AF (ParAF) is more closely related to inflammation. On the basis of inhibiting myocardial physiological uptake, 18F-fluorodeoxyglucosepositron emission tomography/computed tomography (18F-FDG PET/CT) is an established imaging modality to detect cardiac inflammation. We aimed to decipher the association between AF and atrial inflammatory activity by 18F-FDG PET/CT.

METHODS

Thirty-five PerAF patients were compared to age and sex matched ParAF group with baseline 18F-FDG PET/CT scans prior to radiofrequency catheter ablation (RFCA) in the prospective case-control study. High-fat and low-carbohydrate diet and prolonged fast (HFLC+Fast) was applied to all AF patients before PET/CT. Then 22 AF patients with positive right atrial (RA) wall FDG uptake (HFLC+Fast) were randomly selected and underwent HFLC+Fast+heparin the next day. The CHA2DS2-VASc score was calculated to evaluate the risk of stroke. Clinical data, ECG, echocardiography, and atrial 18F-FDG uptake were compared.

RESULTS

PerAF patients had significantly higher probability of RA wall positive FDG uptake and higher SUVmax than ParAF group [91.4% VS. 28.6%, P < 0.001; SUVmax: 4.10(3.20-4.90) VS. 2.60(2.40-3.10), P < 0.001]. Multivariate logistic regression analyses demonstrated that RA wall SUVmax was the independent influencing factor of PerAF (OR = 1.80, 95%CI 1.02-3.18, P = 0.04). In 22 AF patients with RA wall positive FDG uptake (HFLC+Fast), the "HFLC+Fast+Heparin" method did not significantly change RA wall FDG uptake evaluated by either quantitative analysis or visual analysis. High CHA2DS2-VASc score group had higher RA wall 18F-FDG uptake [3.35 (2.70, 4.50) vs, 2.8 (2.4, 3.1) P = 0.01].

CONCLUSIONS

RA wall FDG positive uptake was present mainly in PerAF. A higher RA wall 18F-FDG uptake was an independent influencing factor of PerAF. RA wall FDG uptake based on 18F-FDG PET/CT may indicate pathological inflammation.

TRIAL REGISTRATION

http://www.chictr.org.cn , ChiCTR2000038288.

Inflammatory bowel disease and atrial fibrillation: a contemporary overview

Atrial fibrillation is the most common arrhythmia in clinical practice and it is associated with increased morbidity and mortality. Atrial fibrillation is linked with inflammatory signaling while inflammation and oxidative stress promote atrial remodeling promoting the development and perpetuation of the arrhythmia. On the other hand, inflammatory bowel disease (IBD) is considered a chronic inflammatory condition with flares and remissions. IBD has been associated with an increased risk of atherosclerotic cardiovascular disease but its relationship with atrial fibrillation has not been studied well. Recent epidemiological evidence indicates an association between IBD and atrial fibrillation, especially during flares/hospitalizations. This brief review provides a concise overview of all available data regarding the association between IBD and atrial fibrillation including the predictive role of electrocardiographic and echocardiographic markers. Several unresolved issues including the thromboembolic risk in this setting and the potential role of antiinflammatory interventions are also discussed.

Experimental study on the effect of chlorhexidine gluconate (CG)-induced atrial fibrillation on renal water and sodium metabolism

To construct an animal model of atrial fibrillation and observe the effect of acute atrial fibrillation on renal water and sodium metabolism in mice. A total of 20 C57 mice were randomly assigned to 2 groups (n = 10/group): control group (CON) and atrial fibrillation group (AF). The mice model of atrial fibrillation was induced by chlorhexidine gluconate (CG) in combination with transesophageal atrial spacing. The urine of the two groups of mice was collected, and then we calculate the urine volume and urine sodium content. The expression of TGF-β and type III collagen in the atrial myocardium of the two groups was detected by immunohistochemistry and Western Blot. The levels of CRP and IL-6 in blood were observed by ELISA, and the NF-κB, TGF-β, collagen type III, AQP2, AQP3, AQP4, ENaC-β, ENaC-γ, SGK1 and NKCC proteins in the kidneys of the two groups of mice was observed by Western Blot. Compared with CON, the expression of TGF-β and type III collagen in the atrial myocardium of the mice in AF were increased, the levels of CRP and IL-6 in the blood in AF were increased, and the renal NF-κB, TGF-β, type III collagen AQP2, AQP3, ENaC-β, ENaC-γ, SGK1 and NKCC protein expression in AF were up-regulated. The level of urine volume and urine sodium content in AF were significantly reduced. In the acute attack of atrial fibrillation, the formation of renal inflammatory response and fibrosis is activated, and the renal water and sodium metabolism is hindered, which is related to the up-regulated of the expressions of renal NKCC, ENaC and AQPs.

Prediction of incident atrial fibrillation with cardiac biomarkers and left atrial volumes

OBJECTIVE

Atrial fibrillation is a common arrhythmia associated with risk of stroke, heart failure and death. We aimed to elucidate the associations of cardiac biomarkers, echocardiographic left atrial volumetric indices and risk of prevalent and incident atrial fibrillation in the general population.

METHODS

We assessed cardiac troponin T (cTnT), N-terminal pro-B-type natriuretic peptide (NT-proBNP), growth differentiation factor 15 (GDF-15), maximum (LAVi_max) and minimum (LAVi_min) indexed left atrial volumes and left atrial emptying fraction (LAEF) in subjects born in 1950 participating in the prospective observational cohort, Akershus Cardiac Examination 1950 Study. The Cohorts for Heart and Ageing Research in Genomic Epidemiology for Atrial Fibrillation risk score and sex was used to adjust for residual risk of atrial fibrillation.

RESULTS

Out of 3487 subjects, 157 (4.5%) had prevalent and 123 (3.5%) had incident atrial fibrillation. Echocardiographic left atrial volumes and cardiac biomarkers associated with prevalent atrial fibrillation, but GDF-15 was non-significant in adjusted analysis. Incident atrial fibrillation was predicted by LAVi_max (adjusted HR 1.51, 95% CI 1.30 to 1.75), LAVi_min (adjusted HR 1.52, 95% CI 1.35 to 1.72), LAEF (adjusted HR 1.24, 95% CI 1.04 to 1.48) and NT-proBNP (adjusted HR 1.57, 95% CI 1.32 to 1.85). cTnT and NT-proBNP provided incremental prognostic information to left atrial volumes, but GDF-15 demonstrated no prognostic value for incident atrial fibrillation.

CONCLUSIONS

In the general population, echocardiographic left atrial volumetric indices and NT-proBNP, but not cTnT and GDF-15, associate with prevalent atrial fibrillation and with risk of incident atrial fibrillation. cTnT and NT-proBNP provide incremental prognostic information to echocardiography.

The relationship between leukocyte to albumin ratio and atrial fibrillation severity

BACKGROUND

An increased leukocyte count is a sign of inflammation and has been demonstrated to be a predisposing factor and complication of atrial fibrillation. Similarly, albumin, the major protein in the serum, is also considered an acute phase reactant protein that has osmotic and anti-inflammatory properties, and a low albumin level is a known factor associated with severity in many pathologies, including atrial fibrillation. The neutrophil percentage-to-albumin ratio (NPAR) and other emerging leukocyte counts/albumin ratios have been reliable systemic inflammation-based predictors of mortality and complications in various diseases, but they have not yet been used with atrial fibrillation. This study's aim was to explore whether the leukocyte to albumin ratio could also serve as a useful index in estimating atrial fibrillation severity, including the severity of atrial fibrillation secondary to stroke, to provide a new and more objective tool than the conventional and medical history-based CHA2DS2-VASc score.

MATERIALS AND METHODS

Data were retrospectively collected from the Wuhan University Zhongnan Hospital database from January 1st to December 31st, 2021. The patients were classified into 2 groups: Group 1-low severity and Group 2- moderate to high severity, and diverse statistical analyses were conducted to evaluate the relationship between the leukocyte-to-albumin ratio and AF severity.

RESULTS

Only 2329 test subjects met the inclusion criteria. We had 727 test subjects (381 males and 346 females) categorized into the low severity cohort and 1601 test subjects (932 males and 670 females) in the moderate to high severity group. The difference in mean age between the two groups was significant (95% CI [-2.682 to -0.154] p = 0.028), and the difference in the LAR mean rank between the two groups was significant (p = 0.00). The Chi-square test of association yielded the following results: the relationship between the LAR level and category of severity was statistically significant (p = 0.00), and the Mantel‒Haenszel statistic association odds ratio was OR = 0.657. 95% CI OR [0.549-0.787] p = 0.000. The association between sex and atrial fibrillation severity also reached statistical significance. However, sex and LAR were found to be independent factors in atrial fibrillation (Chi-square p value = 0.564).

CONCLUSION

It has been demonstrated throughout this investigation that the leukocyte to albumin ratio could provide key clues in clinical practice and contribute to thromboembolism risk assessment in the setting of atrial fibrillation.

Bidirectional effects of oral anticoagulants on gut microbiota in patients with atrial fibrillation

Background

The imbalance of gut microbiota (GM) is associated with a higher risk of thrombosis in patients with atrial fibrillation (AF). Oral anticoagulants (OACs) have been found to significantly reduce the risk of thromboembolism and increase the risk of bleeding. However, the OAC-induced alterations in gut microbiota in patients with AF remain elusive.

Methods

In this study, the microbial composition in 42 AF patients who received long-term OAC treatment (AF-OAC group), 47 AF patients who did not (AF group), and 40 volunteers with the risk of AF (control group) were analyzed by 16S rRNA gene sequencing of fecal bacterial DNA. The metagenomic functional prediction of major bacterial taxa was performed using the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) software package.

Results

The gut microbiota differed between the AF-OAC and AF groups. The abundance of Bifidobacterium and Lactobacillus decreased in the two disease groups at the genus level, but OACs treatment mitigated the decreasing tendency and increased beneficial bacterial genera, such as Megamonas. In addition, OACs reduced the abundance of pro-inflammatory taxa on the genus Ruminococcus but increased certain potential pathogenic taxa, such as genera Streptococcus, Escherichia-Shigella, and Klebsiella. The Subgroup Linear discriminant analysis effect size (LEfSe) analyses revealed that Bacteroidetes, Brucella, and Ochrobactrum were more abundant in the anticoagulated bleeding AF patients, Akkermansia and Faecalibacterium were more abundant in the non-anticoagulated-bleeding-AF patients. The neutrophil-to-lymphocyte ratio (NLR) was lower in the AF-OAC group compared with the AF group (P < 0.05). Ruminococcus was positively correlated with the NLR and negatively correlated with the CHA2DS2-VASc score (P < 0.05), and the OACs-enriched species (Megamonas and Actinobacteria) was positively correlated with the prothrombin time (PT) (P < 0.05). Ruminococcus and Roseburia were negatively associated with bleeding events (P < 0.05).

Conclusions

Our study suggested that OACs might benefit AF patients by reducing the inflammatory response and modulating the composition and abundance of gut microbiota. In particular, OACs increased the abundance of some gut microbiota involved in bleeding and gastrointestinal dysfunction indicating that the exogenous supplementation with Faecalibacterium and Akkermansia might be a prophylactic strategy for AF-OAC patients to lower the risk of bleeding after anticoagulation.

Atrial fibrillation and stroke

INTRODUCTION

Stroke is one of the leading causes of mortality and morbidity globally. Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. It is set to reach epidemic proportions. AF is associated with a five-fold increase in risk of stroke. Strokes caused by AF more often are fatal or result in severe disability. Even though the incidence of stroke has been significantly reduced by oral anticoagulation, AF is thought to account for a significant proportion of cryptogenic strokes where no etiology is identified.

AREAS COVERED

This article reviews the literature related to AF and stroke, pathophysiological insights, diagnosis of AF in stroke patients, and its management (Graphical Abstract).

EXPERT OPINION

The pathophysiology of thrombogenesis that links AF and stroke is not well understood and is an area of active research to identify new therapeutic targets to prevent AF and stroke. As the nature of AF and stroke is multifaceted, an integrated care approach to managing AF and stroke is increasingly essential.

Blood-Based Biomarkers to Search for Atrial Fibrillation in High-Risk Asymptomatic Individuals and Cryptogenic Stroke Patients

Background

Atrial fibrillation (AF) increases the risk of ischemic stroke in asymptomatic individuals and may be the underlying cause of many cryptogenic strokes. We aimed to test the usefulness of candidate blood-biomarkers related to AF pathophysiology in two prospective cohorts representative of those populations.

Methods

Two hundred seventy-four subjects aged 65–75 years with hypertension and diabetes from the AFRICAT cohort, and 218 cryptogenic stroke patients aged >55 years from the CRYPTO-AF cohort were analyzed. AF was assessed by 4 weeks of monitoring with a wearable Holter device (NuuboTM™). Blood was collected immediately before monitoring started. 10 candidate biomarkers were measured by automated immunoassays (Roche, Penzberg) in the plasma of all patients. Univariate and logistic regression analyses were performed in each cohort separately.

Results

Atrial fibrillation detection rate was 12.4% (AFRICAT cohort) and 22.9% (CRYPTO-AF cohort). 4 biomarkers were significantly increased in asymptomatic individuals with AF [Troponin-T, Angiopoietin-2 (Ang-2), Endocan, and total N-terminal pro-B type natriuretic peptide (NT-proBNP)] and 7 biomarkers showed significantly higher concentrations in cryptogenic stroke patients with AF detection [growth differentiation factor 15, interleukin 6, Troponin-T, Ang-2, Bone morphogenic protein 10, Dickkopf-related protein 3 (DKK-3), and total NT-proBNP]. The models including Ang-2 and total NT-proBNP [AUC 0.764 (0.665–0.863)], and Ang-2 and DKK-3 [AUC = 0.733 (0.654–0.813)], together with age and sex, showed the best performance to detect AF in high-risk asymptomatic individuals, and in cryptogenic stroke patients, respectively.

Conclusion

Blood-biomarkers, in particular, total NT-proBNP, DKK-3, and Ang-2, were associated with AF reflecting two mechanistically different pathways involved in AF pathophysiology (AF stretch and vascular changes). The combination of these biomarkers could be useful in AF screening strategies in the primary care setting and also for searching AF after cryptogenic stroke.

Assessment and Mitigation of Bleeding Risk in Atrial Fibrillation and Venous Thromboembolism: Executive Summary of a European and Asia-Pacific Expert Consensus Paper

While there is a clear clinical benefit of oral anticoagulation in patients with atrial fibrillation (AF) and venous thromboembolism (VTE) in reducing the risks of thromboembolism, major bleeding events (especially intracranial bleeds) may still occur and be devastating. The decision for initiating and continuing anticoagulation is often based on a careful assessment of both thromboembolism and bleeding risk. The more common and validated bleeding risk factors have been used to formulate bleeding risk stratification scores, but thromboembolism and bleeding risk factors often overlap. Also, many factors that increase bleeding risk are transient and modifiable, such as variable international normalized ratio values, surgical procedures, vascular procedures, or drug-drug and food-drug interactions. Bleeding risk is also not a static "one-off" assessment based on baseline factors but is dynamic, being influenced by aging, incident comorbidities, and drug therapies. In this executive summary of a European and Asia-Pacific Expert Consensus Paper, we comprehensively review the published evidence and propose a consensus on bleeding risk assessments in patients with AF and VTE, with a view to summarizing "best practice" when approaching antithrombotic therapy in these patients. We address the epidemiology and size of the problem of bleeding risk in AF and VTE, and review established bleeding risk factors and summarize definitions of bleeding. Patient values and preferences, balancing the risk of bleeding against thromboembolism, are reviewed, and the prognostic implications of bleeding are discussed. We propose consensus statements that may help to define evidence gaps and assist in everyday clinical practice.

Brain Natriuretic Peptide Biomarkers in Current Clinical and Therapeutic Scenarios of Heart Failure

Brain natriuretic peptide (BNP) and its inactive N-terminal fragment, NT-proBNP, are serum biomarkers with key roles in the management of heart failure (HF). An increase in the serum levels of these peptides is closely associated with the pathophysiological mechanisms underlying HF such as the presence of structural and functional cardiac abnormalities, myocardial stretch associated with a high filling pressure and neuro-hormonal activation. As BNP and NT-proBNP measurements are possible, several studies have investigated their clinical utility in the diagnosis, prognostic stratification, monitoring and guiding therapy of patients with HF. BNP and NT-proBNP have also been used as criteria for enrollment in randomized trials evaluating the efficacy of new therapeutic strategies for HF. Nevertheless, the use of natriuretic peptides is still limited in clinical practice due to the controversial aspect of their use in different clinical settings. The purpose of this review is to discuss the main issues associated with using BNP and NT-proBNP serum levels in the management of patients with HF under current clinical and therapeutic scenarios.

Assessment and mitigation of bleeding risk in atrial fibrillation and venous thromboembolism: A Position Paper from the ESC Working Group on Thrombosis, in collaboration with the European Heart Rhythm Association, the Association for Acute CardioVascular Care and the Asia-Pacific Heart Rhythm Society

Whilst there is a clear clinical benefit of oral anticoagulation (OAC) in patients with atrial fibrillation (AF) and venous thromboembolism (VTE) in reducing the risks of thromboembolism, major bleeding events (especially intracranial bleeds) may still occur and be devastating. The decision to initiate and continue anticoagulation is often based on a careful assessment of both the thromboembolism and bleeding risk. The more common and validated bleeding risk factors have been used to formulate bleeding risk stratification scores, but thromboembolism and bleeding risk factors often overlap. Also, many factors that increase bleeding risk are transient and modifiable, such as variable international normalized ratio values, surgical procedures, vascular procedures, or drug-drug and food-drug interactions. Bleeding risk is also not a static 'one off' assessment based on baseline factors but is dynamic, being influenced by ageing, incident comorbidities, and drug therapies. In this Consensus Document, we comprehensively review the published evidence and propose a consensus on bleeding risk assessments in patients with AF and VTE, with the view to summarizing 'best practice' when approaching antithrombotic therapy in these patients. We address the epidemiology and size of the problem of bleeding risk in AF and VTE, review established bleeding risk factors, and summarize definitions of bleeding. Patient values and preferences, balancing the risk of bleeding against thromboembolism are reviewed, and the prognostic implications of bleeding are discussed. We propose consensus statements that may help to define evidence gaps and assist in everyday clinical practice.

Coronavirus disease 2019 in patients with cardiovascular disease: clinical features and implications on cardiac biomarkers assessment

INTRODUCTION

Previous cardiovascular disease (CVD) and myocardial involvement are common in coronavirus disease-19 (COVID-19). We investigated relationships between CVD, cardiac biomarkers and outcome in COVID-19.

METHODS

We analyzed n = 252 patients from a multicenter study and provided comparison according to the presence or absence of underlying CVD. Cardiac biomarkers high-sensitivity Troponin [upper reference of normality (URN) 35 pg/ml for Troponin I and 14 pg/ml for Troponin T] and natriuretic peptides (Nt-pro-B-type natriuretic peptide, URN 300 pg/ml and B-type natriuretic peptide, URN 100 pg/ml) were both available in n = 136.

RESULTS

Mean age was 69 ± 16 years (56% men, 31% with previous CVD). Raised hs-Troponin and natriuretic peptides were detected in 36 and 50% of the cases respectively. Age, chronic obstructive pulmonary disease, hemoglobin, hs-Troponin and natriuretic peptides were independently associated with underlying CVD (P < 0.05 for all). Compared with the normal biomarkers subgroups, patients with isolated hs-Troponin elevation had higher in-hospital mortality (31 vs. 4%, P < 0.05), similar CVD prevalence (15 vs. 11%) and trend towards higher D-dimer (930 vs. 397 ng/ml, P = 0.140). Patients with both biomarkers elevated had higher age, D-dimer, CVD and in-hospital mortality prevalence compared with other subgroups (all P < 0.05 for trend). Outcome analysis revealed previous CVD [model 1: OR 2.72 (95% CI 1.14-6.49), P = 0.024. model 2: OR 2.65 (95% CI 1.05-6.71), P = 0.039], hs-Troponin (log10) [OR 2.61 (95% CI 1.21-5.66), P = 0.015] and natriuretic peptides (log10) [OR 5.84 (95%CI 2.43-14), P < 0.001] to be independently associated with in-hospital mortality.

CONCLUSION

In our population, previous CVD was part of a vulnerable phenotype including older age, comorbidities, increased cardiac biomarkers and worse prognosis. Patients with isolated increase in hs-Troponin suffered higher mortality rates despite low prevalence of CVD, possibly explained by higher COVID-19-related systemic involvement.

A meta-analysis of clinical risk factors for stroke in anticoagulant-naïve patients with atrial fibrillation

AIMS

The aim of this study is to summarize data from prospective cohort studies on clinical predictors of stroke and systemic embolism in anticoagulant-naïve atrial fibrillation (AF) patients.

METHODS AND RESULTS

EMBASE, MEDLINE, Global Index Medicus, and Web of Science were searched to identify all studies published by 28 November 2019. Forty-seven studies reporting data from 1 756 984 participants in 15 countries were included. The pooled incidence of stroke in anticoagulant-naïve AF patients was 23.8 per 1000 person-years (95% CI 19.7-28.2). Older age was associated with incident stroke or systemic embolism, with a pooled hazard ratio (HR) of 2.14 (95% CI 1.85-2.47), 2.83 (95% CI 2.27-3.51), and 6.87 (95% CI 6.33-7.44) for age 65-75, ≥75, and ≥85 years, respectively. Other predictors of stroke or systemic embolism included history of stroke or TIA (HR 2.84, 95% CI 2.19-3.67), hypertension (HR 1.60, 95% CI 1.37-1.86), diabetes (HR 1.28, 95% CI 1.20-1.37), heart failure (HR 1.25, 95% CI 1.11-1.40), peripheral artery disease (pooled HR 1.35, 95% CI 1.04-1.75), vascular disease (pooled HR 1.21, 95% CI 1.06-1.39), and prior myocardial infarction (pooled HR 1.08, 95% CI 1.03-1.14). Female sex was a predictor of thromboembolism in studies outside Asia (HR 1.33, 95% CI 1.15-1.55), but not in those done in Asia (HR 0.95, 95% CI 0.81-1.10).

CONCLUSION

This study confirms age and prior stroke as the strongest predictors of stroke or systemic embolism in anticoagulant-naive AF patients. Other predictors include hypertension, diabetes, heart failure, and vascular disease. Female sex seems not to be universally associated with stroke or systemic embolism.

Rhythm monitoring strategies for atrial fibrillation detection in patients with cryptogenic stroke: A systematic review and meta-analysis

Objective

To summarize data on atrial fibrillation (AF) detection rates and predictors across different rhythm monitoring strategies in patients with cryptogenic stroke (CS) or embolic stroke of undetermined source (ESUS).

Methods

MEDLINE, Embase, and Web of Science were searched to identify all published studies providing relevant data through July 6, 2020. Random-effects meta-analysis method was used to pool estimates.

Results

We included 47 studies reporting on a pooled population of 8,215 patients with CS or ESUS. Using implantable cardiac monitor (ICM), the pooled rate of AF was 12.2% (95% CI 9.4–15.0) at 3 months, 16.0% (95% CI 13.2–18.8) at 6 months, 18.7% (95% CI 15.7–21.7) at 12 months, 22.8% (95% CI 19.1–26.5) at 24 months, and 28.5% (95% CI 17.6–39.3) at 36 months. AF rates were significantly higher in patients with ESUS vs CS (22.0% vs 14.2%; p < 0.001) at 6 months, and in studies using Reveal LINQ vs Reveal XT ICM (19.1% vs 13.0%; p = 0.001) at 12 months. Using mobile cardiac outpatient telemetry (MCOT), the pooled rate of AF was 13.7% (95% CI 10.2–17.2) at 1 month. Predictors of AF detection with ICM included older age, CHA₂DS₂-VASc score, left atrial enlargement, P wave maximal duration and prolonged PR interval.

Conclusion

The yield of ICM increases with the duration of monitoring. More than a quarter of patients with CS or ESUS will be diagnosed with AF during follow-up. About one in seven patients had AF detected within a month of MCOT, suggesting that a non-invasive rhythm monitoring strategy should be considered before invasive monitoring.

Cardiac Adiposity and Arrhythmias: The Role of Imaging

Increased cardiac fat depots are metabolically active tissues that have a pronounced pro-inflammatory nature. Increasing evidence supports a potential role of cardiac adiposity as a determinant of the substrate of atrial fibrillation and ventricular arrhythmias. The underlying mechanism appears to be multifactorial with local inflammation, fibrosis, adipocyte infiltration, electrical remodeling, autonomic nervous system modulation, oxidative stress and gene expression playing interrelating roles. Current imaging modalities, such as echocardiography, computed tomography and cardiac magnetic resonance, have provided valuable insight into the relationship between cardiac adiposity and arrhythmogenesis, in order to better understand the pathophysiology and improve risk prediction of the patients, over the presence of obesity and traditional risk factors. However, at present, given the insufficient data for the additive value of imaging biomarkers on commonly used risk algorithms, the use of different screening modalities currently is indicated for personalized risk stratification and prognostication in this setting.