Genetic architecture of spatial electrical biomarkers for cardiac arrhythmia and relationship with cardiovascular disease

The 3-dimensional spatial and 2-dimensional frontal QRS-T angles are measures derived from the vectorcardiogram. They are independent risk predictors for arrhythmia, but the underlying biology is unknown. Using multi-ancestry genome-wide association studies we identify 61 (58 previously unreported) loci for the spatial QRS-T angle (N = 118,780) and 11 for the frontal QRS-T angle (N = 159,715). Seven out of the 61 spatial QRS-T angle loci have not been reported for other electrocardiographic measures. Enrichments are observed in pathways related to cardiac and vascular development, muscle contraction, and hypertrophy. Pairwise genome-wide association studies with classical ECG traits identify shared genetic influences with PR interval and QRS duration. Phenome-wide scanning indicate associations with atrial fibrillation, atrioventricular block and arterial embolism and genetically determined QRS-T angle measures are associated with fascicular and bundle branch block (and also atrioventricular block for the frontal QRS-T angle). We identify potential biology involved in the QRS-T angle and their genetic relationships with cardiovascular traits and diseases, may inform future research and risk prediction.

Clinical utility of the 4S-AF scheme in predicting progression of atrial fibrillation: data from the RACE V study

AIMS

The recent 4S-AF (scheme proposed by the 2020 ESC AF guidelines to address stroke risk, symptom severity, severity of AF burden and substrate of AF to provide a structured phenotyping of AF patients in clinical practice to guide therapy and assess prognosis) scheme has been proposed as a structured scheme to characterize patients with atrial fibrillation (AF). We aimed to assess whether the 4S-AF scheme predicts AF progression in patients with self-terminating AF.

METHODS AND RESULTS

We analysed 341 patients with self-terminating AF included in the well-phenotyped Reappraisal of Atrial Fibrillation: Interaction between HyperCoagulability, Electrical remodelling, and Vascular Destabilization in the Progression of AF (RACE V) study. Patients had continuous monitoring with implantable loop recorders or pacemakers. AF progression was defined as progression to persistent or permanent AF or progression of self-terminating AF with >3% burden increase. Progression of AF was observed in 42 patients (12.3%, 5.9% per year). Patients were given a score based on the components of the 4S-AF scheme. Mean age was 65 [interquartile range (IQR) 58-71] years, 149 (44%) were women, 103 (49%) had heart failure, 276 (81%) had hypertension, and 38 (11%) had coronary artery disease. Median CHA2DS2-VASc (the CHA2DS2-VASc score assesses thromboembolic risk. C, congestive heart failure/left ventricular dysfunction; H, hypertension; A2, age ≥ 75 years; D, diabetes mellitus; S2, stroke/transient ischaemic attack/systemic embolism; V, vascular disease; A, age 65-74 years; Sc, sex category (female sex)) score was 2 (IQR 2-3), and median follow-up was 2.1 (1.5-2.6) years. The average score of the 4S-AF scheme was 4.6 ± 1.4. The score points from the 4S-AF scheme did not predict the risk of AF progression [odds ratio (OR) 1.1 95% CI 0.88-1.41, C-statistic 0.53]. However, excluding the symptoms domain, resulting in the 3S-AF (4S-AF scheme without the domain symptom severity, only including stroke risk, severity of AF burden and substrate of AF) scheme, predicted the risk of progression (OR 1.59 95% CI 1.15-2.27, C-statistic 0.62) even after adjusting for sex and age.

CONCLUSIONS

In self-terminating AF patients, the 4S-AF scheme does not predict AF progression. The 3S-AF scheme, excluding the symptom domain, may be a more appropriate score to predict AF progression.

TRIAL REGISTRATION NUMBERS

Clinicaltrials.gov NCT02726698 for RACE V.

Animal models and animal-free innovations for cardiovascular research: current status and routes to be explored. Consensus document of the ESC Working Group on Myocardial Function and the ESC Working Group on Cellular Biology of the Heart

Cardiovascular diseases represent a major cause of morbidity and mortality, necessitating research to improve diagnostics, and to discover and test novel preventive and curative therapies, all of which warrant experimental models that recapitulate human disease. The translation of basic science results to clinical practice is a challenging task, in particular for complex conditions such as cardiovascular diseases, which often result from multiple risk factors and comorbidities. This difficulty might lead some individuals to question the value of animal research, citing the translational 'valley of death', which largely reflects the fact that studies in rodents are difficult to translate to humans. This is also influenced by the fact that new, human-derived in vitro models can recapitulate aspects of disease processes. However, it would be a mistake to think that animal models do not represent a vital step in the translational pathway as they do provide important pathophysiological insights into disease mechanisms particularly on an organ and systemic level. While stem cell-derived human models have the potential to become key in testing toxicity and effectiveness of new drugs, we need to be realistic, and carefully validate all new human-like disease models. In this position paper, we highlight recent advances in trying to reduce the number of animals for cardiovascular research ranging from stem cell-derived models to in situ modelling of heart properties, bioinformatic models based on large datasets, and state-of-the-art animal models, which show clinically relevant characteristics observed in patients with a cardiovascular disease. We aim to provide a guide to help researchers in their experimental design to translate bench findings to clinical routine taking the replacement, reduction, and refinement (3R) as a guiding concept.

Atrial fibrillation in the presence and absence of heart failure enhances expression of genes involved in cardiomyocyte structure, conduction properties, fibrosis, inflammation, and endothelial dysfunction

BACKGROUND

Little is known about genome-wide changes in the atrial transcriptome as a cause or consequence of atrial fibrillation (AF), and the effect of its common and clinically relevant comorbidity-heart failure (HF).

OBJECTIVE

The purpose of this study was to explore candidate disease processes for AF by investigating gene expression changes in atrial tissue samples from patients with and without AF, stratified by HF.

METHODS

RNA sequencing was performed in right and left atrial appendage tissue in 195 patients undergoing open heart surgery from centers participating in the CATCH-ME consortium (no history of AF, n = 91; paroxysmal AF, n = 53; persistent/permanent AF, n = 51). Analyses were stratified into patients with/without HF (n = 75/120) and adjusted for age, sex, atrial side, and a combination of clinical characteristics.

RESULTS

We identified 35 genes associated with persistent AF compared to patients without a history of AF, both in the presence or absence of HF (false discovery rate <0.05). These were mostly novel associations, including 13 long noncoding RNAs. Genes were involved in regulation of cardiomyocyte structure, conduction properties, fibrosis, inflammation, and endothelial dysfunction. Gene set enrichment analysis identified mainly inflammatory gene sets to be enriched in AF patients without HF, and gene sets involved in cellular respiration in AF patients with HF.

CONCLUSION

Analysis of atrial gene expression profiles identified numerous novel genes associated with persistent AF, in the presence or absence of HF. Interestingly, no consistent transcriptional changes were associated with paroxysmal AF, suggesting that AF-induced changes in gene expression predominate other changes.

Smartphone and wearable detected atrial arrhythmias in Older Adults: Results of a fully digital European Case finding study

Aims

Simplified detection of atrial arrhythmias via consumer-electronics would enable earlier therapy in at-risk populations. Whether this is feasible and effective in older populations is not known.

Methods and results

The fully remote, investigator-initiated Smartphone and wearable detected atrial arrhythmia in Older Adults Case finding study (Smart in OAC-AFNET 9) digitally enrolled participants ≥65 years without known atrial fibrillation, not receiving oral anticoagulation in Germany, Poland, and Spain for 8 weeks. Participants were invited by media communications and direct contacts. Study procedures adhered to European data protection. Consenting participants received a wristband with a photoplethysmography sensor to be coupled to their smartphone. The primary outcome was the detection of atrial arrhythmias lasting 6 min or longer in the first 4 weeks of monitoring. Eight hundred and eighty-two older persons (age 71 ± 5 years, range 65-90, 500 (57%) women, 414 (47%) hypertension, and 97 (11%) diabetes) recorded signals. Most participants (72%) responded to adverts or word of mouth, leaflets (11%) or general practitioners (9%). Participation was completely remote in 469/882 persons (53%). During the first 4 weeks, participants transmitted PPG signals for 533/696 h (77% of the maximum possible time). Atrial arrhythmias were detected in 44 participants (5%) within 28 days, and in 53 (6%) within 8 weeks. Detection was highest in the first monitoring week [incidence rates: 1st week: 3.4% (95% confidence interval 2.4-4.9); 2nd-4th week: 0.55% (0.33-0.93)].

Conclusion

Remote, digitally supported consumer-electronics-based screening is feasible in older European adults and identifies atrial arrhythmias in 5% of participants within 4 weeks of monitoring (NCT04579159).

A new efficient and integrated pathway for patient evaluation prior to atrial fibrillation ablation

AIM

In this quality improvement project, a care pathway for patients considered for atrial fibrillation (AF) ablation was optimized with the goals to improve the patient journey and simultaneously integrate prospective data collection into the clinical process.

METHODS AND RESULTS

The Lean Six Sigma approach was used to map the pre-existing process, identify constraints and formulate countermeasures. The percentage of patients going through the full pre-ablation preparation that eventually underwent AF ablation, number of hospital visits and consultations, pathway compliance, and completeness of scientific data were measured before and after pathway optimisation. Constraints in the process were (1) lack of standardized processes, (2) inefficient use of resources, (3) lack of multidisciplinary integration, (4) lack of research integration, and (5) suboptimal communication. The impact of the corresponding countermeasures (defining a uniform process, incorporating 'go/no-go' moment, introducing a 'one-stop-shop', integrating prospective data collection, and improving communication) was studied for 33 patients before and 26 patients after pathway optimisation. After optimisation, the percentage of patients receiving a full pre-ablation preparation that eventually underwent AF ablation increased from 59% to 94% (p < 0.01). Fewer hospital visits (3.2 ± 1.2 versus 2.3 ± 0.8, p = 0.01) and electrophysiologist consultations (1.8 ± 0.7 versus 1.0 ± 0.3, p < 0.01) were required after pathway optimisation. Pathway compliance and complete collection of scientific data increased significantly (3% versus 73%, p < 0.01 and 15% versus 73%, p < 0.01, respectively).

CONCLUSION

The optimisation project resulted in a more efficient evaluation of patients considered for AF ablation. The new more efficient process includes prospective data collection and facilitates easy conduct of research studies focused on improvements of patient outcomes.

We all know A and B, but what about C? Exploring the management of modifiable risk factors in patients with atrial fibrillation

Background

The European Society of Cardiology (ESC) guidelines for the management of atrial fibrillation (AF) advise to treat AF according to the ABC pathway: A, anticoagulation, B, better symptom control, and C, comorbidities and cardiovascular risk factor management. Optimal treatment of comorbidities and risk factors slows AF progression and improves success rates of rhythm interventions for AF. However, several studies report underdiagnosis and therefore possible undertreatment for common cardiovascular comorbidities.

Purpose

This study aims to evaluate how common modifiable cardiovascular risk factors are managed in AF patients referred for catheter ablation.

Methods

This is a substudy of the ISOLATION study, a prospective cohort study including consecutive patients with paroxysmal or persistent AF referred for AF ablation. Screening for common modifiable risk factors for AF is structurally embedded in the work-up for AF ablation in the two participating centres. In the present study the prevalence of the following risk factors at this screening moment was assessed: (1) body mass index (BMI) above the target BMI for ablation (≥27 kg/m2), (2) hypertension, defined as on-site systolic blood pressure &gt;130 mmHg and/or diastolic blood pressure &gt;80 mmHg, (3) decreased glucose tolerance or diabetes mellitus, defined as HbA1c ≥6.5%, (4) dyslipidaemia, defined as low-density lipoprotein (LDL) ≥2.5 mmol/l, (5) regular alcohol consumption, defined as self-reported consumption of &gt;15 standardized units/week, and (6) sleep disordered breathing (SDB), defined as apnoea-hypopnoea index (AHI) ≥15 assessed with home sleep tests (subset of patients).

Results

Among the 981 patients studied (median age 65 [59–71] years old, 64% male, 69% paroxysmal AF), previously diagnosed comorbidities were common (46% hypertension, 7% diabetes, 22% dyslipidaemia, 10% SDB), and a large proportion of patients received targeted treatment (Table 1). However, non-optimally managed risk factors remained significant (Figure 1). BMI ≥27 kg/m2 was present in 56% of patients. High systolic and diastolic blood pressure were present in 62% and 51% of patients, respectively, and any form of high blood pressure (either systolic or diastolic) was seen in 72% of patients. HbA1c was found to be above target ranges in 9% patients and LDL in 56%. A weekly alcohol consumption of ≥15 units was reported by 4% of patients. Screening for SDB was performed in a subset of patients (n=287), for whom AHI was ≥15 in 52%. Overall, 9% of patients had 4 or more non-optimally controlled modifiable risk factors, whereas the median number of modifiable risk factors was 2 [1–3].

Conclusions

Structural screening revealed a high prevalence of non-optimally controlled modifiable cardiovascular risk factors in patients referred for AF catheter ablation. According to recent ESC guidelines, improving treatment of comorbidities may improve AF ablation success rates and even reduce mortality.

Funding Acknowledgement

Type of funding sources: None.

The use of novel 3D dark-blood late gadolinium enhancement MRI to determine the optimal threshold for atrial scar after pulmonary vein isolation ablation

Background

Dark-blood late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) is proved to be superior to bright-blood LGE MRI in localising subtle subendocardial scar in the ventricles, because of improved contrast between myocardial scar and blood. However, dark-blood LGE MRI has not yet been applied to identify atrial scar in the left atrium (LA) and therefore its threshold to determine scar is unknown.

Purpose

To determine the optimal intensity threshold for 3D dark-blood LGE MRI for atrial ablation scar after pulmonary vein isolation (PVI)

Methods

Twelve re-do PVI patients with symptomatic atrial fibrillation (AF) who underwent pre-procedural 3D dark-blood LGE MRI were included. The image intensity ratio (IIR = myocardial intensity normalized to the blood pool) from the LGE MRI were calculated using ADAS-AF. High-density bipolar voltages (BiV) maps were recorded during sinus rhythm prior to ablation. All BiV locations ≤5 mm from the ADAS LA anatomy were compared with the corresponding IIR, using custom-made software in MATLAB. To achieve an equal ratio between scar (BiV ≤0.15 mV) and non-scar (BiV &gt;0.15 mV) for each patient, non-scar pairs were randomly resampled to the same number as scar pairs. This was repeated 10 times and for every random selection, receiver operating characteristics (ROC) analysis was performed to determine the optimal IIR threshold (provided by the Youden's index) for scar defined as BiV &lt;0.15 mV (Figure 1). All IIR thresholds and areas under the curve were averaged to determine the overall performance and optimal IIR threshold.

Results

Of the 12 included patients, 8 had prior cryo PVI, 2 radiofrequency PVI, and 2 surgical/hybrid AF ablation. ROC curve analysis estimated the average optimal threshold for predicting BiV &lt;0.15 mV to be an IIR of 1.106, with a mean area under the curve (AUC) of 0.73 (Figure 1). Figure 2 shows two examples of the IIR map (A), BiV map (B), and the correspondence map (C) providing information on spatial agreement between IIR and BiV. This individual qualitative assessment provides insight into the spatial variation between techniques and may facilitate future studies on the pathophysiological understanding of atrial ablation scarring.

Conclusion

This is the first study to use the novel 3D dark-blood whole heart LGE MRI to evaluate LA ablation scar after PVI. Based on the ROC analyses, an IIR of 1.106 is the optimal threshold for atrial ablation scar, defined as high density bipolar voltage &lt;0.15 mV.

Funding Acknowledgement

Type of funding sources: None.

Genetic analyses of the electrocardiographic QT interval and its components identify additional loci and pathways

The QT interval is an electrocardiographic measure representing the sum of ventricular depolarization and repolarization, estimated by QRS duration and JT interval, respectively. QT interval abnormalities are associated with potentially fatal ventricular arrhythmia. Using genome-wide multi-ancestry analyses (>250,000 individuals) we identify 177, 156 and 121 independent loci for QT, JT and QRS, respectively, including a male-specific X-chromosome locus. Using gene-based rare-variant methods, we identify associations with Mendelian disease genes. Enrichments are observed in established pathways for QT and JT, and previously unreported genes indicated in insulin-receptor signalling and cardiac energy metabolism. In contrast for QRS, connective tissue components and processes for cell growth and extracellular matrix interactions are significantly enriched. We demonstrate polygenic risk score associations with atrial fibrillation, conduction disease and sudden cardiac death. Prioritization of druggable genes highlight potential therapeutic targets for arrhythmia. Together, these results substantially advance our understanding of the genetic architecture of ventricular depolarization and repolarization.

Association between comorbidities and left and right atrial dysfunction in patients with paroxysmal atrial fibrillation: Analysis of AF-RISK

BACKGROUND

To identify the association between comorbidities and left atrial (LA) and right atrial (RA) function in patients with paroxysmal atrial fibrillation (AF).

METHODS

This is a cross-sectional study. Speckle-tracking echocardiography was performed in 344 patients with paroxysmal AF at baseline, and available in 298 patients after 1-year follow-up. The number of comorbidities (hypertension, diabetes mellitus, coronary artery disease, body mass index > 25 kg/m², age > 65 years, moderate to severe mitral valve regurgitation and kidney dysfunction (estimated glomerular filtration rate < 60 ml/min/1.73 m²)) was determined and the association with atrial strain was tested.

RESULTS

Mean age of the patients was 58 (SD 12) years and 137 patients were women (40%). Patients with a higher number of comorbidities had larger LA volumes (p for trend <0.001), and had a decrease in all strain phases from the LA and RA, except for the RA contraction phase (p for trend 0.47). A higher number of comorbidities was associated with LA reservoir and conduit strain decrease independently of LA volume (p < 0.001, p < 0.001 respectively). Patients with 1-2 comorbidities, but not patients with 3 or more comorbidities, showed a further progression of impaired LA and RA function in almost all atrial strain phases at 14 [13-17] months follow-up.

CONCLUSIONS

In patients with paroxysmal AF, individual and combined comorbidities are related to lower LA and RA strain. In patients with few comorbidities, impairment in atrial function progresses during one year of follow-up. Whether comorbidity management prevents or reverses decrease in atrial function warrants further study.

Early diagnosis and better rhythm management to improve outcomes in patients with atrial fibrillation: the 8th AFNET/EHRA consensus conference

Despite marked progress in the management of atrial fibrillation (AF), detecting AF remains difficult and AF-related complications cause unacceptable morbidity and mortality even on optimal current therapy. This document summarizes the key outcomes of the 8th AFNET/EHRA Consensus Conference of the Atrial Fibrillation NETwork (AFNET) and the European Heart Rhythm Association (EHRA). Eighty-three international experts met in Hamburg for 2 days in October 2021. Results of the interdisciplinary, hybrid discussions in breakout groups and the plenary based on recently published and unpublished observations are summarized in this consensus paper to support improved care for patients with AF by guiding prevention, individualized management, and research strategies. The main outcomes are (i) new evidence supports a simple, scalable, and pragmatic population-based AF screening pathway; (ii) rhythm management is evolving from therapy aimed at improving symptoms to an integrated domain in the prevention of AF-related outcomes, especially in patients with recently diagnosed AF; (iii) improved characterization of atrial cardiomyopathy may help to identify patients in need for therapy; (iv) standardized assessment of cognitive function in patients with AF could lead to improvement in patient outcomes; and (v) artificial intelligence (AI) can support all of the above aims, but requires advanced interdisciplinary knowledge and collaboration as well as a better medico-legal framework. Implementation of new evidence-based approaches to AF screening and rhythm management can improve outcomes in patients with AF. Additional benefits are possible with further efforts to identify and target atrial cardiomyopathy and cognitive impairment, which can be facilitated by AI.

Prevalence and determinants of atrial fibrillation progression in paroxysmal atrial fibrillation

OBJECTIVE

Atrial fibrillation (AF) often progresses from paroxysmal AF (PAF) to more permanent forms. To improve personalised medicine, we aim to develop a new AF progression risk prediction model in patients with PAF.

METHODS

In this interim-analysis of the Reappraisal of AF: Interaction Between HyperCoagulability, Electrical Remodelling, and Vascular Destabilisation in the Progression of AF study, patients with PAF undergoing extensive phenotyping at baseline and continuous rhythm monitoring during follow-up of ≥1 year were analysed. AF progression was defined as (1) progression to persistent or permanent AF or (2) progression of PAF with >3% burden increase. Multivariable analysis was done to identify predictors of AF progression.

RESULTS

Mean age was 65 (58-71) years, 179 (43%) were female. Follow-up was 2.2 (1.6-2.8) years, 51 of 417 patients (5.5%/year) showed AF progression. Multivariable analysis identified, PR interval, impaired left atrial function, mitral valve regurgitation and waist circumference to be associated with AF progression. Adding blood biomarkers improved the model (C-statistic from 0.709 to 0.830) and showed male sex, lower levels of factor XIIa:C1-esterase inhibitor and tissue factor pathway inhibitor, and higher levels of N-terminal pro-brain natriuretic peptide, proprotein convertase subtilisin/kexin type 9 and peptidoglycan recognition protein 1 were associated with AF progression.

CONCLUSION

In patients with PAF, AF progression occurred in 5.5%/year. Predictors for progression included markers for atrial remodelling, sex, mitral valve regurgitation, waist circumference and biomarkers associated with coagulation, inflammation, cardiomyocyte stretch and atherosclerosis. These prediction models may help to determine risk of AF progression and treatment targets, but validation is needed.

TRIAL REGISTRATION NUMBER

NCT02726698.

Rationale and Design of the ISOLATION Study: A Multicenter Prospective Cohort Study Identifying Predictors for Successful Atrial Fibrillation Ablation in an Integrated Clinical Care and Research Pathway

Introduction

Continuous progress in atrial fibrillation (AF) ablation techniques has led to an increasing number of procedures with improved outcome. However, about 30-50% of patients still experience recurrences within 1 year after their ablation. Comprehensive translational research approaches integrated in clinical care pathways may improve our understanding of the complex pathophysiology of AF and improve patient selection for AF ablation.

Objectives

Within the "IntenSive mOlecular and eLectropathological chAracterization of patienTs undergoIng atrial fibrillatiOn ablatioN" (ISOLATION) study, we aim to identify predictors of successful AF ablation in the following domains: (1) clinical factors, (2) AF patterns, (3) anatomical characteristics, (4) electrophysiological characteristics, (5) circulating biomarkers, and (6) genetic background. Herein, the design of the ISOLATION study and the integration of all study procedures into a standardized pathway for patients undergoing AF ablation are described.

Methods

ISOLATION (NCT04342312) is a two-center prospective cohort study including 650 patients undergoing AF ablation. Clinical characteristics and routine clinical test results will be collected, as well as results from the following additional diagnostics: determination of body composition, pre-procedural rhythm monitoring, extended surface electrocardiogram, biomarker testing, genetic analysis, and questionnaires. A multimodality model including a combination of established predictors and novel techniques will be developed to predict ablation success.

Discussion

In this study, several domains will be examined to identify predictors of successful AF ablation. The results may be used to improve patient selection for invasive AF management and to tailor treatment decisions to individual patients.

Replicated gene expression changes in patients with atrial fibrillation

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union Horizon 2020 CATCH ME; Cardiovascular Research Netherlands RACE V

Background

Little is known about changes in the atrial transcriptome associated with paroxysmal and persistent atrial fibrillation (AF).

Purpose

To identify major molecular mechanisms in AF, we determined consistent differential expression (DE) between atrial tissue samples from well-characterized patients with paroxysmal or persistent AF and patients without a history of AF (no AF) in two independent patient cohorts.

Methods

Poly-A tailed RNA from left and right atrial appendage tissue samples from independent discovery and replication cohorts CATCH ME (n=192) and RACE V (n=122) was sequenced and analyzed according to patient AF history. Analyses were performed stratified by atrial side, adjusting for age, sex, heart failure and a combination of clinical characteristics determined by principal component analysis. Transcripts were considered DE in CATCH ME if their fold change reached transcriptome-wide significance (false discovery rate (FDR) &lt; 0.05). DE transcripts in each rhythm comparison were replicated in RACE V if we observed a concordant direction of effect and a within-set FDR &lt; 0.05 in the same comparison.

Results

Persistent AF compared to no AF was associated with 184 left atrial DE transcripts in CATCH ME of which 85 (46%) were replicated in RACE V, and with 208 right atrial DE transcripts in CATCH ME of which 86 (41%) were replicated in RACE V. Overall, 26 transcripts were discovered and replicated in both atria. Discovered but non-replicated transcripts often did exhibit concordant direction of effect (left: 78%, right: 83%). Replicated transcripts consisted of protein coding genes, antisense and non-coding RNAs. Protein coding genes showed involvement in pathways linking persistent AF to cardiomyocyte structure, conduction properties, fibrosis, inflammation, molecule trafficking, and endothelial dysfunction. Interestingly, paroxysmal AF was not consistently associated with DE transcripts in any comparison. Principal component analysis of the expression of the 26 transcripts strongly associated with persistent AF did however reveal a distinct paroxysmal AF expression profile in-between no AF and persistent AF patients in the first principal component scores (Figure 1).

Conclusion

RNA sequencing of human atrial tissue samples identified many transcripts associated with persistent AF in left and/or right atria, discovered and replicated using two independent cohorts. These consistent findings of AF-induced changes provide a starting point for targeted proteomic analysis and single-nucleus sequencing to further unravel the molecular mechanisms underlying AF progression to persistent AF, and biomarker development to quantify AF progression and enable precision medicine in individual patients.

The role of the autonomous nervous system in atrial fibrillation progression. Data from the RACE V study

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): We acknowledge the support from the Netherlands Cardiovascular Research Initiative: an initiative with support of the Dutch Heart Foundation, CVON 2014-9: Reappraisal of Atrial Fibrillation: interaction between hyperCoagulability, Electrical remodelling, and Vascular destabilisation in the progression of AF (RACE V). Unrestricted grant support from Medtronic Trading NL B.V.

Background

Atrial fibrillation (AF) progression is associated with adverse outcome.

The autonomic nervous system plays a yet unsettled role in initiation and progression of AF.

Purpose

To assess in patients with paroxysmal selfterminating AF differences in phenotype and AF progression depending on the role of the autonomic nervous system in triggering AF episodes.

Methods

Patients with paroxysmal AF included in the Reappraisal of AF: Interaction Between HyperCoagulability, Electrical Remodelling, and Vascular Destabilisation in the Progression of AF (RACE V) study were analysed. Patients were extensively phenotyped at baseline and received continuous rhythm monitoring with an implantable loop recorder (ILR).To adequately define the role of the autonomic nervous system in triggering AF only patients with at least 3 selfterminating AF episodes were included. ILR data were used to assess whether AF was mainly vagally induced (&gt;80% of episodes starting during night time) or mainly adrenergically induced (&gt;80% starting during daytime), and to assess the development of AF progression. If a patient could not be identified as either vagal or adrenergic, they were classified as mixed AF. Primary outcome were differences in AF progression between the three groups. AF progression was defined as (1) progression to persistent or permanent AF, or (2) progression of PAF with &gt;3% burden increase. Follow-up was 2.2 (1.6-2.8) years.

Results

278 patients were included, median was age 66 (59-71) years, 117 (42%) were women (Table 1). Patients with vagally or adrenergically induced AF had less comorbidities compared to mixed AF patients (median 2 versus 2 versus 3, respectively, p=0.012). In the mixed group, compared to either the vagal or adrenergic group the estimated glomerular filtration rate was slightly worse (median 78 versus 84 versus 82 mL/min*1.73m2 in the mixed versus vagal and adrenergic group, respectively, p=0.018), diabetes was more common (12% versus 5% versus 0%, respectively, p=0.031). Obesity was most often present in the vagal group (38% versus 12% versus 27%, in the vagal versus adrenergic versus mixed group, respectively p=0.028). Progression rates in the vagal versus adrenergic versus mixed groups were 5% versus 5% versus 24%, respectively (p=0.013 vagal versus mixed and p=0.008 adrenergic versus mixed group, respectively)(Figure).

Conclusion

Important differences exist between AF patients depending on their autonomic nervous system associated triggering mechanisms. Patients with either vagally or adrenergically induced AF have less comorbidities as compared to those with a mixed initiation type of AF and showed lower AF progression rates.

The impact of a structured polygraphy screening incorporated in a novel remote mobile health pathway on sleep apnoea prevalence in patients with atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

Untreated obstructive sleep apnoea (OSA) contributes to progression of atrial fibrillation (AF) and reduces the success rate of heart rhythm control strategies. OSA remains one of the most frequently underdiagnosed modifiable risk factors in AF patients due to a lack of standardized screening methods and low awareness.

Purpose

To assess the impact of implementation of a structured remote OSA screening and management pathway on the prevalence of OSA in AF patients scheduled for AF ablation procedures.

Methods

In October 2020, a novel remote OSA screening and management pathway (VIRTUAL-SAFARI) was introduced in two AF outpatient clinics in the Netherlands. Consecutive patients scheduled for AF ablation were offered OSA screening consisting of sending a portable home sleep test to patients’ homes to perform a remote sleep recording for one night, analysis by a sleep physician, discussion of results with the patient, and initiation of treatment (when applicable). The impact of this structural screening strategy was assessed by comparing the prevalence of concomitant OSA (defined as apnoea-hypopnoea index ≥5) for patients scheduled for AF ablation in the year before and after introduction of the OSA management pathway.

Results

A total of 733 patients was studied, 308 in the year before (Oct ’19 - Sep ’20) and 425 in the year after (Oct ’20 - Sep ’21) introduction of the VIRTUAL-SAFARI pathway. Median age was 65 [58-71], 64% was male and median body mass index (BMI) was 27 [25-30] kg/m2. Baseline characteristics were comparable for the groups before and after introduction of the pathway (Table 1).

In the cohort before pathway introduction, OSA had been diagnosed in 26 patients (8%, Figure 1) and was treated with positive airway pressure in 10 cases (3%).

In the cohort after pathway introduction, OSA had previously been diagnosed in 53 patients (12%). Eighty-eight percent of patients without previous OSA screening was referred via the remote pathway. Results of the sleep recordings were available for 213 (59%) at the time of this analysis. Previously unknown OSA was diagnosed in 184 patients (86% of available recordings), increasing the prevalence of confirmed OSA to 237 (55%). For 22% of patients, results of sleep recordings are pending. Absence of OSA was confirmed in 9%, and 13% of patients had not been screened (e.g. because of patient preference or logistical reasons). After pathway introduction, 82 patients (19%) were treated or received advice to start treatment with positive airway pressure. Treatment decisions are pending for 9% of the cohort.

Conclusion

After the implementation of structured remote OSA screening in a well characterized cohort of consecutive patients scheduled for AF ablation, the prevalence of diagnosed OSA increased from 8% to 55%. Whether appropriate risk factor management, including treatment of OSA identified by structured screening, will improve AF outcomes needs to be tested in future studies.

The 3S-AF scheme, rather than the 4S-AF scheme, predicts progression in patients with paroxysmal atrial fibrillation: data from RACE V study

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): support from the Netherlands Cardiovascular Research Initiative: an initiative with support of the Dutch Heart Foundation, CVON 2014-9: Reappraisal of Atrial Fibrillation: interaction between hyperCoagulability, Electrical remodelling, and Vascular destabilisation in the progression of AF (RACE V).

Purpose

To assess whether the 4S-AF scheme predicts AF progression, cardiovascular hospitalizations and mortality in patients with self-terminating paroxysmal AF.

Methods

We analysed well-phenotyped patients with paroxysmal AF from the Reappraisal of Atrial Fibrillation: Interaction between HyperCoagulability, Electrical remodelling, and Vascular Destabilisation in the Progression of AF (RACE V study). From the 417 patients included in RACE V, 341 (82%) had echocardiography available. Patient had continuous monitoring with implantable loop recorders or pacemakers. Primary endpoint of RACE V was AF progression, defined as (1) progression to persistent or permanent AF, or (2) progression of PAF with &gt;3% burden increase. Median follow-up was 2.2 (1.6-2.8) years. Patients were given a score based on the components of the 4S-AF scheme (St, stroke=1; Sy, symptoms=2; Sb, Severity of burden=2; Su, Substrate=5) to a total maximum of 10 points (table 1). Left atrial fibrosis was not evaluated in our patients and therefore not included into the score. A score of zero (0) in the AF burden domain was given to all patients due to the presence of paroxysmal AF in all. A modified 4S-AF scheme was designed by eliminating the symptom domain, resulting in a 3S-AF scheme. Logistic regression was performed to assess AF progression and the composite endpoint of cardiovascular hospitalizations and mortality, C-statistic to assess prediction of the score, for both using the 4S-AF and the modified 3S-AF scheme.

Results

Mean age was 65 (IQR 58-71) years, 149 (44%) were women, 103 (48%) had heart failure (HFrEF 6 [2%]; HFpEF 97 [46%]), 276 (81%) had hypertension, 38(11%) had coronary artery disease and 162(48%) atherosclerosis (Table 2, Panel A). Based on the 4S-AF scheme, patients had an average score of 4.5±1.3, the majority had a score under 5 (n=272, 80%), 20% of the score was explained by the S1 domain (stroke), 16% of the score was explained by the Sy domain (symptoms), and 64% of the score was explained by the Su domain (substrate). The score points from the 4S-AF scheme did not predict the risk of AF progression (OR 1.08 95%CI 0.84 – 1.39, C-statistic 0.53) nor the composite endpoint (OR 0.79 95%CI 0.53 – 1.20, C-statistic 0.42, Table 2, Panel B). However, when excluding the Sy domain (symptoms) from the scheme, the 3S-AF scheme, it predicted the risk of progression (OR 1.54 95%CI 1.12 – 2.18, C-statistic 0.61, Table 2, Panel B).

Conclusion

In paroxysmal AF patients the 4S-AF scheme does not predict AF progression nor the composite endpoint cardiovascular hospitalizations and mortality. Although symptoms are important for choosing the treatment strategy, they may be less relevant to determine AF progression, cardiovascular hospitalization and mortality. To assess progression, the 3S-AF scheme may be more appropriate.

Atrial fibrillation and age synergistically increase clotting potential and promote atrial structural remodeling in goats

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): Netherlands Heart Foundation, European Union

Background

Age is a risk factor for atrial fibrillation (AF) as well as for stroke in patients with AF. However, the effect of ageing on AF mechanisms and on coagulation activity is not well understood.

Purpose

To evaluate the effect of age and AF on coagulation activity, AF characteristics, and atrial structural remodeling.

Methods

Four groups of female goats were investigated: Young sham (Y-Sh: sinus rhythm, &lt;3 years old, n=9), Young AF (Y-AF: 4 weeks of AF, &lt;3 years old, n=7), Old sham (O-Sh: sinus rhythm, &gt;8 years old, n=6), and Old AF (O-AF, 4 weeks of AF, &gt;8 years old, n=8). Groups were matched for body weight. AF was maintained using implantable pacemakers in both AF groups. Clotting potential, expressed as the ability of activated plasma to generate thrombin, was measured using tissue factor-induced thrombin generation assays at baseline and 4 weeks (final). A terminal experiment was performed with atrial contact mapping to study electrophysiological AF properties and to collect atrial tissue for histological analysis.

Results

Thrombin generation analysis showed that 4 weeks of AF induced a significant increase in clotting potential in old, but not in young goats. AF complexity and hemodynamics were not affected by age alone. AF, however, significantly increased the right atrial pressure in old (O-Sh: 6.4±1.9 vs. O-AF: 11.4±3.1 mmHg, p=0.02), but not in young goats. AF induced atrial myocyte hypertrophy and left atrial epicardial endomysial fibrosis in old goats, while this was not the case in young goats.

Conclusion

Four weeks of AF and advanced age synergistically enhanced coagulation potential and promoted atrial structural remodeling in goats. Complexity of atrial conduction was affected by AF, but not by age.

Optimization of a care pathway before atrial fibrillation ablation with the integration of translational research into routine clinical care

Funding Acknowledgements

Type of funding sources: None.

Background

The diagnostic work-up for atrial fibrillation (AF) catheter ablation is often complex and expensive. Improving the organization of this work-up may help to streamline patient journeys and to reduce administrative burden and costs. Additionally, reorganizing the existing work-up provides the opportunity to integrate (translational) research into routine clinical care, hereby contributing to improved patient selection and improved care for future patients.

Purpose

The aim of this project was to optimize a care pathway for patients considered for AF ablation, with the goals to improve the patient journey and simultaneously integrate research into the clinical process.

Methods

The Lean Six Sigma approach was used to map the pre-existing process, identify constraints in the process and formulate countermeasures. The impact of this pathway optimization was evaluated using four outcome measures: (1) efficient use of medical resources, defined as the percentage of patients receiving the pre-ablation work-up and eventually undergoing AF ablation, (2) number of hospital visits and consultations with a cardiologist, (3) pathway compliance, defined as the percentage of patients that completed the work-up with a maximum of 2 outpatient hospital visits, a maximum of 1 cardiologist consultation, laboratory results available, and a complete echocardiogram available, and (4) completeness of scientific data, defined as the availability of a predefined set of relevant variables (clinical indicators, medication, laboratory results and echocardiography derived data).

Results

Five root causes for constraints in the pre-existing work-up were identified and corresponding countermeasures were formulated (Figure 1). The impact of the countermeasures was studied for 33 patients before and 26 patients after pathway optimization. After optimization, efficient use of resources increased from 44% to 95% (p&lt;0.01). The project resulted in fewer hospital visits per patient (3.2 ±1.2 versus 2.3 ±0.8, p=0.01) and fewer cardiologist consultations (1.8 ±0.7 versus 1.0 ±0.3, p&lt;0.01). Pathway compliance increased significantly (3% versus 73%, p&lt;0.01), an increase that was reflected in all separate components of overall pathway compliance (Figure 2, panel A). The percentage of available data for scientific research increased from 80% to 94% (p&lt;0.01), resulting in a complete dataset in 73% of patients after, compared to only 15% of patients prior to the optimization project (p&lt;0.01, Figure 2, panel B).

Conclusions

This optimization project resulted in a more efficient care pathway for patients considered for AF ablation. The structural integration of research into the care pathway may lay the foundations for further improvements of AF care in the future.

High-density sequential mapping of repetitive atrial conduction patterns during atrial fibrillation

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This work was supported by PersonalizeAF project. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 860974.

Background

Localized AF drivers are considered candidate ablation targets for patients with persistent atrial fibrillation (AF). These drivers are expected to be associated with repetitive atrial conduction patterns during AF. Thus, tools that localize atrial sites with repetitive electrical activity might be instrumental in guiding ablation.

Purpose

High-density mapping catheters cover only a small portion of the atria. Combining sequential recordings from those catheters could provide a more complete picture of repetitive conduction patterns, and enable AF driver localization. We hypothesize that the repetitive activity generated by local AF drivers can be detected by means of high-coverage composite activation maps generated from spatially overlapping sequential recordings.

Methods

Repetitive conduction patterns were detected in a goat model of AF (249-electrode epicardial mapping array, 2.4mm inter-electrode distance, n=16) by exploiting recurrence plots (Fig 1A-C). Cross-recurrences of repetitive patterns in sequential recordings were detected in spatially overlapping recording locations. Using this information, local activation maps were aligned and combined into larger composite average activation maps (Fig. 1D-F). The proposed algorithm was tested on a dataset formed by segmenting the epicardial mapping area into four spatially overlapping regions. The proposed algorithm was then used to merge these segmented regions back together to reconstruct the original mapping area. Reconstruction accuracy was measured as the correlation between original and reconstructed average activation patterns (Fig. 2.). Statistical analyses were performed to investigate a possible relation between reconstruction accuracy and pattern properties such as duration, size, complexity, and cycle length. Patterns were classified as single peripheral, multiple waves, focal source, or re-entry based on the preferential conduction velocity directions.

Results

Among 1021 detected repetitive patterns, 328 spatiotemporally stable- patterns were present in all four artificially segmented recordings. In 32% of these, repetitiveness was associated with a local driver-either focal or re-entrant. Composite maps could be generated in 75% of the cases, and mainly in case of larger patterns (p&lt;0.01). The average correlation between the actual activation maps and the composite maps was 0.86 ±0.16. Only pattern duration showed a statistically significant low correlation with reconstruction accuracy of composite maps (r=0.126, p&lt;0.05). There was no significant difference in the reconstruction accuracy for multiple waves, focal sources and re-entries.

Conclusion(s)

The proposed framework could align sequentially recorded repetitive epicardial patterns over different atrial regions, to produce high-fidelity composite maps. The performance was minimally affected by pattern properties, thus suggesting potential use with a diverse range of AF patterns.

Atrial endomysial fibrosis is associated with sex, atrial fibrillation, heart failure and age in cardiac surgery patients: results from the Catch-Me consortium

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Horizon 2020

Background

Risk factors for atrial fibrillation (AF), such as ageing, heart failure and AF itself, enhance AF propensity partly by inducing atrial fibrosis. Atrial endomysial fibrosis, a type of reactive fibrosis occurring between cardiomyocytes, impairs transverse conduction in rapid atrial pacing animal models. The factors underlying transcriptional regulation of endomysial fibrosis are largely unknown.

Objective

To examine the contributions of age, sex, AF and heart failure to the development of endomysial fibrosis in the context of concurrent pathologies. To study genome-wide transcriptional changes associated with endomysial fibrosis in human left and right atrial appendage biopsies (LAA, n=95; RAA, n=76).

Methods

An algorithm for automated quantification of endomysial fibrosis following staining with wheat germ agglutinin (WGA) was employed. Linear mixed models were constructed to determine endomysial fibrosis quantity as a function of AF, heart failure, sex, age and four principal components that accounted for potential confounding effects of other clinical characteristics. RNA sequencing was used to study expression changes in the atrial transcriptome associated with endomysial fibrosis.

Results

Sex, persistent AF, heart failure and age were independently associated with endomysial fibrosis. We identified hundreds (LAA: 386, RAA: 311) of RNA transcripts associated with endomysial fibrosis. None of these associations were independent from the clinical phenotypes. However, explorative gene set enrichment analysis identified association of endomysial fibrosis with gene sets involved in extracellular matrix organization, immune response, cell motility, developmental processes, cardiac muscle contraction and proteostasis in LAA while in RAA only gene sets regulating contractile function were enriched.

Conclusion

Besides AF, female sex, age and heart failure are associated with endomysial fibrosis in the atria. While abundance of none of the differential genes were independently associated with endomysial fibrosis, gene set enrichment analysis suggests an involvement of extracellular matrix organization, immune response, cell motility, developmental processes and cardiac muscle contraction in endomysial fibrosis.

Performance of STOP-BANG questionnaire as sleep apnoea screening tool and development of a novel pre-selection model in patients with atrial fibrillation - insights from the Virtual-SAFARI study

Funding Acknowledgements

Type of funding sources: None.

Background

Sleep-disordered breathing (SDB) is highly prevalent in patients with atrial fibrillation (AF) and its screening is recommended in this population. The STOP-BANG questionnaire is widely used as SDB screening tool, but the subjective assessment of some of its parameters might limit its validity to detect SDB in AF patients.

Purpose

We assessed the performance of the STOP-BANG questionnaire to detect SDB with the use of a mobile health-based portable home sleep test given as reference in a cohort of AF patients. Moreover, we explored options to improve pre-selection for SDB screening in this cohort.

Methods

Consecutive AF patients who were referred for AF catheter ablation in two AF outpatient clinics and without previous history of SDB and/or SDB screening, were included prospectively. Patients characteristics together with STOP-BANG questionnaire were assessed at baseline visitation. STOP-BANG scores of 3-4 and 5-8 were interpreted as intermediate and high risk for SDB, respectively. All patients were digitally referred to a virtual SDB management pathway, independent of STOP-BANG score. Patients received a portable home sleep test to detect SDB, which patients used for one night at home after instructions. Sleep recordings were accessed by sleep physicians via a secured cloud and sleep reports were discussed with patients and referring physicians. Apnoea-hypopnoea-indexes (AHI) of &gt;=15 and of &gt;= 30 were interpreted as moderate-to-severe and severe SDB, respectively. Results of the STOP-BANG and the home sleep test were compared and performance of the STOP-BANG questionnaire was assessed. Uni- and multivariable logistic regression analyses based on patient characteristics were used to construct a nomogram to improve pre-selection for SDB screening in this cohort.

Results

A total of 156 patients (median age 65 years, 63.8% male) were included. According to results from the home sleep test, 53% of patients were diagnosed with moderate-to-severe SDB, including 16% with severe SDB. STOP-BANG questionnaire performed poorly with an area under the receiver operating characteristic curve (AUROC) of 0.661 and 0.684 in predicting moderate-to-severe and severe SDB, respectively. On multivariable logistic analysis, independent predictors for moderate-to-severe SDB were body-mass-index (BMI), age and apnoeas. A nomogram was built on this variables (Fig. 1), which performed good with an AUROC of 0.728 in predicting moderate-to-severe SDB.

Conclusion

In a cohort of AF patients scheduled for AF catheter ablation, SDB was highly prevalent. STOP-BANG questionnaire had poor value for the prediction of moderate-to-severe and severe SDB compared to a systematical SDB screening via home sleep test. Using STOP-BANG questionnaire as a pre-selection tool might lead to frequently undetected and untreated SDB. Whether the nomogram based on our analyses improves pre-selection for SDB screening in AF patients will be validated in a future cohort.

Advanced vascular aging in patients with paroxysmal atrial fibrillation - Data from RACE V

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Dutch Heart Foundation, Medtronic

Background

The incidence of atrial fibrillation (AF) increases exponentially with age. To which extend vascular aging is part of this process is unknown. Pulse wave velocity and carotid intima-media thickness are established markers for vascular aging and have been combined in a vascular aging index as published before(1).

Purpose

We aim to investigate if vascular age exceeds chronological age in our cohort with paroxysmal AF and if yes to which extend.

Methods

In this substudy from RACE V we included 295 patients with paroxysmal AF in which carotid-femoral pulse wave velocity (cfPWV) and carotid intima-media thickness (IMT) were measured. To calculate vascular aging we used a logarithmic formula derived from the Malmö-Cancer-and-Diet study which yields a vascular age index derived from cfPWV, cIMT and chronological age. This vascular aging index (VAI) is a strong predictor of cardiovascular events. (1). All patients underwent cardiac echocardiography and had a native cardiac CT scan in which fat around the heart and coronary calcium were quantified. In 121 patients Agatston scores from the ascending aortic artery were also measured.

Results

Patients in this study had a mean chronological age of 63.8 ± 10.1 years and a vascular age of 71.4 ± 11.7 years. Vascular age was on average 9.3 ± 10.2 years higher than chronological age. Vascular age correlated significantly with markers for diastolic dysfunction, vascular calcification in the coronary arteries as well as the aorta and the amount of epicardial and pericardial fat (table 1).

Conclusions

In patients with PAF vascular age was on average 9.3 years higher than chronological age in our cohort. Advanced vascular age is represented by vascular and myocardial remodeling related to fibrosis, calcification and fat accumulation. The results suggest that in patients with AF enhanced inflammation is leading to fibrosis and calcification. Whether AF is a marker, a mechanism or both in advanced vascular aging warrants further study.

The impact of different fat depots in the body on the progression of atrial fibrillation - data from RACE V

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Dutch Heart Foundation, Medtronic

Background

Paroxysmal atrial fibrillation (PAF) progression is associated with cardiovascular complications and worse outcome. Obesity is independently associated with AF prevalence and progression. The association between different fat depots in the body with AF is unclear.

Aim

We aim to systematically investigate the association of different fat depots in the body with AF.

Methods

417 patients with PAF and continuous rhythm monitoring (implantable loop recorder or pacemaker) were included in the prospective RACE V study. In addition to extensive phenotyping at baseline including calculating BMI and measuring waist circumference (WC) epicardial and pericardial fat were measured on non-contrast enhanced cardiac CT scans by tracing the pericardium manually on every slice and afterwards fat automatically summed between -50 and -150 HU. Epicardial fat was defined as fat within the pericardium, pericardial fat as fat inside the pericardium and adjacent to the pericardium and thoracic fat as adjacent fat outside the pericardium. AF progression was defined as (1) progression to persistent or permanent AF, or (2) progression of PAF with &gt;3% burden increase within 2.2years of follow-up. Multivariable logistic regression analysis was used to analyse the association of different fat pads with AF progression.

Results

Six percent of patients per year showed AF progression (51/417) after a median follow-up of 2.2 (1.6-2.8) years. Multivariate analysis identified WC (odds ratio [OR] 1.03, 95% confidence intervals [CI] 1.01-1.06, p=.014) to be associated with AF progression. Epicardial fat (OR 1.00, 95%CI .99-1.01, p=.407), pericardial fat (OR 1.00, 95%CI .99-1.01, p=.311), thoracic fat (OR 1.00, 95%CI .99-1.01, p=.372), and BMI (OR 1.03, 95%CI .97-1.10, p=.328) showed no relation with AF progression.

Conclusion

AF progression occurred in 6% per year in patients with PAF. In contrast to epicardial, pericardial and thoracic fat measured in a semiautomatic way, WC was the only fat depot associated with AF progression. Whether a more different assessment of obesity and epicardial fat may demonstrate an association with AF progression warrants further study.