Obesity effect on newly diagnosed and recurrent post-ablation atrial fibrillation: a systematic review and meta-analysis

BACKGROUND AND AIMS

The role of overweight and obesity in the development of atrial fibrillation (AF) is well established; however, the differential effect on the occurrence and recurrence of AF remains uncertain. The aim of this review is to compare the effect of underweight and varying degrees of obesity on onset of AF and in recurrent post-ablation AF, and, when possible, in relation to sex.

METHODS

A systematic literature search was conducted in PubMed, Embase, and Cochrane Library from inception to January 31, 2023. Studies reporting frequency of newly-diagnosed AF and of recurrent post-ablation AF in different BMI categories, were included. 3400 records were screened and 50 met the inclusion criteria. Standardized data search and abstraction were performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) Statement. Data were extracted from the manuscripts and were analyzed using a random effect model. The outcome was the occurrence of AF in population studies and in patients undergoing ablation.

RESULTS

Data from 50 studies were collected, of which 27 for newly-diagnosed AF and 23 for recurrent post-ablation AF, for a total of 15,134,939 patients, of which 15,115,181 in studies on newly-diagnosed AF and 19,758 in studies on recurrent post-ablation AF. Compared to normal weight, the increase in AF was significant (p < 0.01) for overweight, obese, and morbidly obese patients for newly-diagnosed AF, and for obese and morbidly obese patients for recurrent post-ablation AF. Newly-diagnosed AF was more frequent in obese female than obese male patients.

CONCLUSION

The effect of increased BMI was greater on the onset of AF, and obese women were more affected than men.

Analyses of lncRNA and mRNA profiles in recurrent atrial fibrillation after catheter ablation

BACKGROUND

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide. Catheter ablation has become a crucial treatment for AF. However, there is a possibility of atrial fibrillation recurrence after catheter ablation. Our study sought to elucidate the role of lncRNA‒mRNA regulatory networks in late AF recurrence after catheter ablation.

METHODS

We conducted RNA sequencing to profile the transcriptomes of 5 samples from the presence of recurrence after AF ablation (P-RAF) and 5 samples from the absence of recurrence after AF ablation (A-RAF). Differentially expressed genes (DEGs) and long noncoding RNAs (DE-lncRNAs) were analyzed using the DESeq2 R package. The functional correlations of the DEGs were assessed through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. A protein‒protein interaction (PPI) network was constructed using STRING and Cytoscape. We also established a lncRNA‒mRNA regulatory network between DE-lncRNAs and DEGs using BEDTools v2.1.2 software and the Pearson correlation coefficient method. To validate the high-throughput sequencing results of the hub genes, we conducted quantitative real-time polymerase chain reaction (qRT‒PCR) experiments.

RESULTS

A total of 28,528 mRNAs and 42,333 lncRNAs were detected. A total of 96 DEGs and 203 DE-lncRNAs were identified between the two groups. GO analysis revealed that the DEGs were enriched in the biological processes (BPs) of "regulation of immune response" and "regulation of immune system process", the cellular components (CCs) of "extracellular matrix" and "cell‒cell junction", and the molecular functions (MFs) of "signaling adaptor activity" and "protein-macromolecule adaptor activity". According to the KEGG analysis, the DEGs were associated with the "PI3K-Akt signaling pathway" and "MAPK signaling pathway." Nine hub genes (MMP9, IGF2, FGFR1, HSPG2, GZMB, PEG10, GNLY, COL6A1, and KCNE3) were identified through the PPI network. lncRNA-TMEM51-AS1-201 was identified as a core regulator in the lncRNA‒mRNA regulatory network, suggesting its potential impact on the recurrence of AF after catheter ablation through the regulation of COL6A1, FGFR1, HSPG2, and IGF2.

CONCLUSIONS

The recurrence of atrial fibrillation after catheter ablation may be associated with immune responses and fibrosis, with the extracellular matrix playing a crucial role. TMEM51-AS1-201 has been identified as a potential key target for AF recurrence after catheter ablation.

Pre-procedural high serum visfatin and tumor necrosis factor-α might predict recurrent atrial fibrillation after catheter ablation

BACKGROUND

Many patients would require repeated ablation procedures owing to recurrent atrial fibrillation with its associated symptoms. Identifying those who are at risk of recurrent AF could assist us to develop preventive strategies and to properly select those who will benefit more from catheter ablation. Our aim is to study the role of preprocedural serum level of certain biomarkers in the prediction of AF recurrence after catheter ablation.

RESULTS

The present study included 117 patients: 26 patients with persistent and 91 patients with paroxysmal AF. Blood samples for estimation of serum levels of studied cytokines were obtained prior to the procedure. Pulmonary vein isolation was performed in all patients through point-by point radiofrequency ablation guided by 3D electroanatomical mapping system. Patients were followed for 12 months for AF recurrence. Forty-one (35%) patients developed AF recurrence. Those patients were significantly older, had significantly higher BMI, lower ejection fraction, and wider maximal left atrial diameter (LAD). Serum hs-CRP, IL-6, TNF-α, visfatin, and adiponectin levels were significantly higher compared to those who did not develop AF recurrence. Correlation analysis showed positive correlations between the incidence of RAF and patients' age, BMI, and maximum LAD and elevated cytokine levels and maximal LAD showed significant correlations with the type of AF and elevated serum TNF-α, visfatin, and adiponectin. Statistical analyses defined elevated serum levels of TNF-α, visfatin, and adiponectin as positive predictors for RAF, and automatic linear modeling analysis showed that elevated serum visfatin, TNF-α, and adiponectin can predict RAF by accuracy rates of 50%, 34%, and 16%, respectively.

CONCLUSIONS

RAF is most probably an outcome of the interplay between patients' clinical data, obesity, and inflammation. Pre-procedural estimation of serum levels of visfatin and TNF-α might determine patients with probability for RAF.

High-power short-duration versus standard-power standard-duration settings for repeat atrial fibrillation ablation

INTRODUCTION

High-power short-duration (HPSD) ablation is a novel strategy using contact force-sensing catheters optimized for radiofrequency ablation for atrial fibrillation (AF). No study has directly compared HPSD versus standard-power standard-duration (SPSD) contact force-sensing settings in patients presenting for repeat ablation with AF recurrence after initial ablation.

METHODS

We studied consecutive cases of patients with AF undergoing repeat ablation with SPSD or HPSD settings after their initial pulmonary vein isolation (PVI) with temperature controlled non-contact force, SPSD or HPSD settings between 6/23/14 and 3/4/20. Procedural data collected included radiofrequency ablation delivery time (RADT). Clinical data collected include sinus rhythm maintenance post-procedure.

RESULTS

A total of 61 patients underwent repeat ablation (36 SPSD, 25 HPSD). A total of 51 patients (83.6%) were found to have pulmonary vein reconnections necessitating repeat isolation, 10 patients (16.4%) had durable PVI and ablation targeted non-PV sources. RADT was shorter when comparing repeat ablation using HPSD compared to SPSD (22 vs 35 min; p = 0.01). There was no difference in sinus rhythm maintenance by Kaplan-Meier survival analysis (log rank test p = 0.87), after 3 or 12-months between groups overall, and when stratified by AF type, left atrial volume index, CHA₂DS₂-VASc score, or left ventricular ejection fraction.

CONCLUSION

We demonstrated that repeat AF ablation with HPSD reduced procedure times with similar sinus rhythm maintenance compared to SPSD in those presenting for repeat ablation.

Temporal trends in atrial fibrillation recurrence rates after ablation between 2005 and 2014: a nationwide Danish cohort study

Aims

During the last decade, ablation has increasingly been used in rhythm control management of patients with atrial fibrillation (AF). Over time, experience and techniques have improved and indications for ablation have expanded. The purpose of this study was to investigate whether the recurrence rate of AF following ablation has improved during last decade.

Methods and results

Through Danish nationwide registers, all patients with first-time AF ablation, between 2005 and 2014 in Denmark were identified. Recurrent AF after ablation was identified with 1 year follow-up. A total of 5425 patients undergoing first-time ablation were included. While patient median age increased over time the median AF duration prior to ablation decreased. The rates of recurrent AF decreased from 45% in 2005-2006 to 31% 2013-2014 with the relative risk of recurrent AF almost halved with an odds ratio of 0.57 [95% confidence intervals (95% CI) 0.47-0.68] in 2013-2014 compared with patients undergoing ablation in 2005-2006. Female gender, hypertension, AF duration >2 years, and cardioversion within 1 year prior to ablation were all associated with an increased risk of recurrent AF.

Conclusion

One year risk of recurrent AF following first-time ablation has almost halved from 2006 to 2014. Hypertension, female sex, cardioversion 1 year prior to ablation, and AF duration for more than 2 years all increased the associated risk of recurrent AF.