Catheter ablation of atrial fibrillation: current status, techniques, outcomes and challengesCatheter ablation of atrial fibrillation: current status, techniques, outcomes, and challenges

The impact of ultrasound-guided vascular access for catheter ablation of left atrial arrhythmias in a high-volume centre

BACKGROUND

Vascular complications are a common occurrence during atrial fibrillation ablation. Observational studies indicate that the utilization of ultrasound (US)-guided puncture may decrease the incidence of vascular complications; however, its routine use is not established in many centres.

METHODS

Patients undergoing catheter ablation for atrial fibrillation were included sequentially. All patients receiving US-guided punctures were prospectively enrolled (US group), while patients who underwent the procedure with standard puncture technique served as control group (No-US group). Periprocedural vascular complications requiring intervention within 30 days of the procedure were defined as the primary endpoint.

RESULTS

A total of 599 patients (average age: 69 ± 11 years, 62.9% male) were analysed. The incidence of vascular complications was lower with the US-guided puncture than with the anatomic landmark-guided puncture (14/299 [4.7%] vs. 27/300 [9%], p = 0.036). The US-guided vascular access significantly reduced the rate of false aneurysms (3/299 [1%] vs. 12/300 [4%], p = 0.019). In addition, the occurrence of arteriovenous fistula (2/299 [0.7%] vs. 4/300 [1.3%], p = 0.686) and haematoma requiring treatment (9/299 [3%] vs. 11/300 [3.7%], p = 0.655) were also lower in the US group. US-guided puncture did not prolong the procedure time (mean procedure time: 57.48 ± 24.47 min vs. 56.09 ± 23.36 min, p = 0.478). Multivariate regression analysis identified female gender (OR 2.079, CI 95% 1.096-3.945, p = 0.025) and conventional vascular access (OR 2.079, CI 95% 1.025-3.908, p = 0.042) as predictors of vascular complications.

CONCLUSIONS

The implementation of US-guided vascular access for left atrial catheter ablation resulted in a significant decrease of the overall vascular complication rate.

Atrial fibrillation in older adults with cancer

Cancer and atrial fibrillation (AF) are common co-morbid conditions in older adults. Both cancer and cancer treatment increase the risk of developing new AF which increases morbidity and mortality. Heart rate and rhythm control along with anticoagulation therapy remain the mainstay of treatment of AF in older adults with both cancer and AF. Adjustments to the treatment may be necessary because of drug interactions with concurrent chemotherapy. Cancer and old age increase the risk of both, thromboembolism and bleeding. The risk of these complications is further enhanced by concomitant cancer therapy, frailty, poor nutrition status and, coexisting geriatric syndromes. Therefore, careful attention needs to be given to the risks and benefits of using anticoagulant medications. This review focuses on the management of AF in older patients with cancer, including at the end-of-life care.

Risk factors for late recurrence in patients with nonvalvular atrial fibrillation after radiofrequency catheter ablation

Objective

To identify the risk factors for postoperative atrial fibrillation (AF) recurrence in nonvalvular AF patients undergoing radiofrequency catheter ablation (CA).

Methods

We retrospectively reviewed the data from 426 of 450 AF patients who underwent CA. Patients were divided into two groups according to recurrence after the operation; the risk factors for AF recurrence were analyzed. A stratification system for lesions was created based on the cutoff of the risk factors; the associations among the subgroups and the AF recurrence rate were analyzed.

Results

AF recurrence occurred in 98 (23.0%) patients. Univariate analysis demonstrated that AF type, hypertrophic cardiomyopathy, left atrial diameter (LAD), left ventricular ejection fraction (LVEF), serum albumin, and D‐dimer concentrations were associated with AF recurrence. AF type (OR =2.907, p < .001), serum albumin concentration (OR =1.112, p < .05), and LAD (OR =1.115, p < .001) were independent risk factors for AF recurrence. The area under the ROC curve of LAD for the prediction of AF recurrence was 0.722 (95% CI: 0.664~0.779) and that of serum albumin for the prediction of AF recurrence was 0.608 (95% CI: 0.545~0.672). Further stratification revealed that patients with persistent or paroxysmal AF with LAD ≥43.5 mm and serum albumin concentration ≥42.2 g/L had a higher rate of AF recurrence than the reference group.

Conclusion

Atrial fibrillation type, LAD, and serum albumin concentration are risk factors for AF recurrence after CA in patients with nonvalvular AF. Patients with persistent AF with LAD ≥43.5 mm and serum albumin concentration ≥42.2 g/L have a higher risk of late AF recurrence after surgery.

Quality indicators for the care and outcomes of adults with atrial fibrillation

AIMS

To develop quality indicators (QIs) that may be used to evaluate the quality of care and outcomes for adults with atrial fibrillation (AF).

METHODS AND RESULTS

We followed the ESC methodology for QI development. This methodology involved (i) the identification of the domains of AF care for the diagnosis and management of AF (by a group of experts including members of the ESC Clinical Practice Guidelines Task Force for AF); (ii) the construction of candidate QIs (including a systematic review of the literature); and (iii) the selection of the final set of QIs (using a modified Delphi method). Six domains of care for the diagnosis and management of AF were identified: (i) Patient assessment (baseline and follow-up), (ii) Anticoagulation therapy, (iii) Rate control strategy, (iv) Rhythm control strategy, (v) Risk factor management, and (vi) Outcomes measures, including patient-reported outcome measures (PROMs). In total, 17 main and 17 secondary QIs, which covered all six domains of care for the diagnosis and management of AF, were selected. The outcome domain included measures on the consequences and treatment of AF, as well as PROMs.

CONCLUSION

This document defines six domains of AF care (patient assessment, anticoagulation, rate control, rhythm control, risk factor management, and outcomes), and provides 17 main and 17 secondary QIs for the diagnosis and management of AF. It is anticipated that implementation of these QIs will improve the quality of AF care.

Catheter Ablation Energy Sources and Myocardial Injury and Coagulation Biomarkers During Uninterrupted Periprocedural Edoxaban Use - A Subanalysis of KYU-RABLE

BACKGROUND

The effects of catheter ablation (CA) energy sources on myocardial injury and coagulation biomarkers among Japanese non-valvular atrial fibrillation patients receiving uninterrupted periprocedural edoxaban are unclear. This KYU-RABLE exploratory subanalysis compared the effects of CA using radiofrequency energy vs. cryoballoon on: (1) myocardial injury; and (2) plasma edoxaban and coagulation biomarker concentrations measured before and after CA.Methods and Results:Plasma creatine kinase (CK), edoxaban, D-dimer, and prothrombin fragment 1+2 (F1+2) concentrations within 1 h before CA were compared with concentrations the day after. All biomarkers increased after CA, regardless of the energy source, but especially with cryoballoon. Significantly higher increases in CK concentrations from before to the day after CA were seen with cryoballoon compared with radiofrequency energy (P<0.0001). Edoxaban concentrations were similar in both groups. Concentrations of D-dimer and F1+2 increased in both groups, but were significantly higher in the cryoballoon group (P<0.0001 and P=0.006, respectively). There were no significant between-group differences in the incidence of thrombotic or bleeding events.

CONCLUSIONS

Uninterrupted edoxaban concentrations were similar in both groups. Both myocardial injury and coagulation biomarkers increased after CA, especially with cryoballoon, but there was no difference in the incidence of thrombotic or bleeding events. These findings suggest the efficacy of uninterrupted edoxaban, regardless of the CA energy source. Periprocedural anticoagulation, particularly with cryoballoon, should be undertaken with care.

Exosomes in atrial fibrillation: therapeutic potential and role as clinical biomarkers

Atrial fibrillation (AF), the most common cardiac arrhythmia, is a global epidemic. AF can cause heart failure and myocardial infarction and increase the risk of stroke, disability, and thromboembolic events. AF is becoming increasingly ubiquitous and is associated with increased morbidity and mortality at higher ages, resulting in an increasing threat to human health as well as substantial medical and social costs. Currently, treatment strategies for AF focus on controlling heart rate and rhythm with medications to restore and maintain sinus rhythm, but this approach has limitations. Catheter ablation is not entirely satisfactory and does not address the issues underlying AF. Research exploring the mechanisms causing AF is urgently needed for improved prevention, diagnosis, and treatment of AF. Exosomes are small vesicles (30-150 nm) released by cells that transmit information between cells. MicroRNAs in exosomes play an important role in the pathogenesis of AF and are established as a biomarker for AF. In this review, a summary of the role of exosomes in AF is presented. The role of exosomes and microRNAs in AF occurrence, their therapeutic potential, and their potential role as clinical biomarkers is considered. A better understanding of exosomes has the potential to improve the prognosis of AF patients worldwide, reducing the global medical burden of this disease.

World Heart Federation Roadmap on Atrial Fibrillation - A 2020 Update

The World Heart Federation (WHF) commenced a Roadmap initiative in 2015 to reduce the global burden of cardiovascular disease and resultant burgeoning of healthcare costs. Roadmaps provide a blueprint for implementation of priority solutions for the principal cardiovascular diseases leading to death and disability. Atrial fibrillation (AF) is one of these conditions and is an increasing problem due to ageing of the world's population and an increase in cardiovascular risk factors that predispose to AF. The goal of the AF roadmap was to provide guidance on priority interventions that are feasible in multiple countries, and to identify roadblocks and potential strategies to overcome them. Since publication of the AF Roadmap in 2017, there have been many technological advances including devices and artificial intelligence for identification and prediction of unknown AF, better methods to achieve rhythm control, and widespread uptake of smartphones and apps that could facilitate new approaches to healthcare delivery and increasing community AF awareness. In addition, the World Health Organisation added the non-vitamin K antagonist oral anticoagulants (NOACs) to the Essential Medicines List, making it possible to increase advocacy for their widespread adoption as therapy to prevent stroke. These advances motivated the WHF to commission a 2020 AF Roadmap update. Three years after the original Roadmap publication, the identified barriers and solutions were judged still relevant, and progress has been slow. This 2020 Roadmap update reviews the significant changes since 2017 and identifies priority areas for achieving the goals of reducing death and disability related to AF, particularly targeted at low-middle income countries. These include advocacy to increase appreciation of the scope of the problem; plugging gaps in guideline management and prevention through physician education, increasing patient health literacy, and novel ways to increase access to integrated healthcare including mHealth and digital transformations; and greater emphasis on achieving practical solutions to national and regional entrenched barriers. Despite the advances reviewed in this update, the task will not be easy, but the health rewards of implementing solutions that are both innovative and practical will be great.

Effects of Atrial Fibrillation-Derived Exosome Delivery of miR-107 to Human Umbilical Vein Endothelial Cells

The aim of this study was to explore the effects of atrial fibrillation (AF)-derived exosome delivery of miR-107 to human umbilical vein endothelial cells (HUVECs) and its related mechanisms. Exosomes were isolated from the plasma of patients with AF and healthy controls, followed by characterization. The expression levels of miR-320d, miR-103a-3p, and miR-107 were measured using real-time quantitative PCR (RT-qPCR). The dual-luciferase reporter gene was used to verify the downstream target of miR-107. Afterward, HUVECs were treated with AF-derived exosomes or transfected with miR-107 mimics. After cell culture, Cell Counting Kit-8, Transwell, and flow cytometry were used to determine cell viability, migration, and apoptosis and cell cycle phase. Finally, RT-qPCR was performed to examine the expression of related genes. NanoSight, transmission electron microscopy, and western blotting showed that exosomes were successfully isolated, and that AF-derived exosomes could be taken up by HUVECs. The expression of miR-107 was significantly higher in AF-derived exosomes than in normal exosomes (p < 0.05). USP14 was shown to be the direct target of miR-107. In addition, miR-107 mimics and AF-derived exosomes significantly suppressed cell viability and migration (p < 0.05) and enhanced cell apoptosis; they also increased G0/G1-phase cells and reduced S-phase cells. RT-qPCR showed that exosomal miR-107 overexpression significantly downregulated the expression of USP14 and Bcl2 (p < 0.05), whereas it markedly upregulated the expression of ERK2, FAK, and Bax (p < 0.05). AF-derived exosomes can deliver miR-107 to HUVECs, and exosomal miR-107 may regulate cell viability, migration, and apoptosis and cell cycle progression by mediating the miR-107/USP14 pathway.

[2020 ESC guidelines on atrial fibrillation : Summary of the most relevant recommendations and innovations]

The new guidelines for the diagnosis and management of atrial fibrillation (AF) were published by the European Society of Cardiology (ESC) in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS) in August 2020. The 2020 guidelines of the ESC on AF summarize the current developments in this field and provide general recommendations for the management of patients with AF based on the principles of evidence-based medicine. Beside the general statements on definition, epidemiology and clinical features of AF, interesting new aspects in screening and diagnosis of AF are also presented. The main novelties of the 2020 guidelines are the proposal of the 4S-AF scheme for a structured characterization of AF that takes the stroke risk, severity of symptoms, severity of AF burden and substrate severity into account. Also new is the ABC approach for improvement of the structured management and treatment results. A further innovation is the introduction of the concept of major risk factors for recurrences in the decision for catheter ablation. This review focuses on the newest and most important recommendations taken from the 2020 ESC guidelines for the diagnosis and management of AF.

Rhythm Control in AF: Have We Reached the Last Frontier?

AF is a worldwide epidemic, affecting approximately 33 million people, and its rising prevalence is expected to account for increasing clinical and public health costs. AF is associated with an increased risk of MI, heart failure, stroke, dementia, chronic kidney disease and mortality. Preserving sinus rhythm is essential for a better outcome. However, because of the inherent limits of both pharmacological and interventional methods, rhythm strategy management is reserved for symptom and quality-of-life improvement. While ‘classical’ antiarrhythmic drug therapy remains the first-line therapy for rhythm control, its efficacy and safety are limited by empirical use, proarrhythmic risk and organ toxicity. Ablative techniques have had an impressive development, but AF ablation still failed to demonstrate a significant impact on hard endpoints. Understanding of the complex mechanisms of AF will help to develop new vulnerable targets to therapy. Promising molecules are under development, intended to fill the gap between the current pharmacological treatment aimed at maintaining sinus rhythm and the expectations from rhythm strategy.