Radiofrequency Catheter Ablation For Atrial Fibrillation: Approaches And Outcomes

Clinical impact of very high-power-short-duration catheters on biomarkers after atrial fibrillation ablation

Background

Very high-power short-duration (vHPSD) catheters are associated with less irrigation fluid load than standard (STD RF) ablation catheters. However, the impact of this fluid reduction on biomarkers in pulmonary vein isolation (PVI) for atrial fibrillation (AF) remains unknown.

Methods and Aim

Biomarkers of heart failure, myocardial injury, and systemic inflammation status as Brain Natriuretic Peptide (BNP), high-sensitivity Troponin I (hsTnI), and C-reactive protein (CRP) were collected pre- and post-procedure of PVI for symptomatic AF. The study aimed to assess the impact of vHPSD catheter compared to an STD catheter (respectively irrigation of 8 vs. 15 mL/min during ablation) on biomarker alterations.

Results

The study included 83 consecutive patients (59 males [71.1%], mean age 62.6 ± 11 years), with vHPSD catheters used in 53 cases (63.9%). No significant baseline differences were observed between groups.Fluid irrigation resulted in significantly lower with vHPSD catheter than STD RF (434.8 ± 105.6 vs. 806.6 ± 256.5 mL, p < .001). Correspondingly, BNP variation was significantly lower in the vHPSD group than in the STD RF group, both in absolute change (12 [IQR -9-47] pg/mL vs. 44.5 [IQR 21-88.7] pg/mL, p = .002) and percentage change (16.3 [IQR -13.2-108.6] % vs. 84.1 [IQR 32.5-172.1] %, p = .012). When considering absolute values, a statistically significant increase in BNP was found only in the STD catheter group (from 52 [IQR 35.2-113.5] to 113 [IQR 66.7-189.5] pg/mL, p < .001), whereas no significant increase was observed in the vHPSD group (p = .06). CRP levels increased post-PVI in both groups, but the delta was significantly lower in the vHPSD group (p = .025). No significant differences in post-procedural hsTnI were detected between groups.

Conclusion

The use of a vHPSD catheter is associated with reduced fluid irrigation and a correspondingly smaller increase in BNP, a biomarker indicative of fluid overload and heart failure.

Real-world single-center preliminary experience of radiofrequency balloon pulmonary vein ablation for atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia and pulmonary vein isolation (PVI) by percutaneous transcatheter ablation is its pivotal treatment. Nowadays, several techniques using different energy sources are used, such as radiofrequency (RF), cryoablation and laser ablation. A new technology that combines the strengths of different techniques has been developed, in particular having both the speed of one-shot techniques and the selectivity and precision of point-by-point RF: the RF balloon (RFB). Recent clinical studies1-3 have demonstrated its efficacy and safety, with good results in terms of first pass isolation, procedural duration and fluoroscopy time. However, real-world data regarding RFB ablation is scarce, therefore with this study we aimed to describe the experience of our center with this technology (one of the first adopting it in our country). We prospectively enrolled in a single-center a total of 20 consecutive patients who underwent AF ablation with RFB. The primary endpoint, i.e. PVI defined as stable absence of any electrical conduction from and into the veins, was met by 18 patient (90 %). Mean procedural and fluoroscopy times were 79 ± 30.68 min and and 15.36 ± 6.57 min, respectively, dwelling time was 30.3 ± 8.09 min. The only complication reported was a single case mild pericardial effusion 24 h after the procedure, likely of inflammatory nature, which was treated conservatively and resolved before discharge. With this study we demonstrated that PVI with RFB appears to be an effective and safe technique in a real world setting, with many upsides and a reduced atrial dwelling time that theoretically could reduce the risk of thromboembolic complications. Further studies on larger number of patients are needed to confirm the results we obtained.

Effectiveness and Safety of Pulsed Field Ablation in Patients With Atrial Fibrillation

BACKGROUND

As a competitive nonthermal energy technique used in atrial fibrillation (AF), the effectiveness and safety of pulsed field ablation (PFA) has remained uncertain.

OBJECTIVES

The authors meta-analysis aimed to investigate the effectiveness and safety of PFA in treating AF patients and compare its outcomes with conventional thermal ablation.

METHODS

The PubMed, Embase, and Cochrane Library databases were systematically searched until January 2024 for relevant studies investigating the use of PFA for AF. A fixed-effects model was used for pooled analysis if the I2 value was <50%; otherwise, a random-effects model was applied.

RESULTS

A total of 46 studies were included in this analysis. The single-arm meta-analysis of 40 studies showed an acute pulmonary vein isolation (PVI) rate of 99.79% per pulmonary vein (PV) and 99.47% per patient, with atrial arrhythmia recurrence rates of 12.36%, 12.42%, and 23.28% at 3, 6, and 12 months, respectively. The safety outcomes incidence was low. In the comparison of 21 studies between PFA and thermal ablation, PFA demonstrated comparable acute PVI rates but a higher first-pass isolation rate. PFA was associated with a lower incidence of atrial arrhythmia recurrence after 3 months and phrenic nerve paralysis or injury, but a higher risk of cardiac perforation or tamponade. Procedure time was shorter with PFA.

CONCLUSIONS

PFA showed noninferiority to thermal ablation in acute PVI and superiority in first-pass isolation, atrial arrhythmia recurrence, phrenic nerve paralysis or injury, and procedure time. However, PFA treatment exhibited a higher risk of cardiac perforation or tamponade.

An Exploratory Pilot Study on the Application of Radiofrequency Ablation for Atrial Fibrillation Guided by Computed Tomography-Based 3D Printing Technology

Radiofrequency ablation (RFA) is the treatment of choice for atrial fibrillation (AF). Additionally, the utilization of 3D printing for cardiac models offers an in-depth insight into cardiac anatomy and cardiovascular diseases. The study aims to evaluate the clinical utility and outcomes of RFA following in vitro visualization of the left atrium (LA) and pulmonary vein (PV) structures via 3D printing (3DP). Between November 2017 and April 2021, patients who underwent RFA at the First Affiliated Hospital of Xinxiang Medical University were consecutively enrolled and randomly allocated into two groups: the 3DP group and the control group, in a 1:1 ratio. Computed tomography angiography (CTA) was employed to capture the morphology and diameter of the LA and PV, which facilitated the construction of a 3D entity model. Additionally, surgical procedures were simulated using the 3D model. Parameters such as the duration of the procedure, complications, and rates of RFA recurrence were meticulously documented. Statistical analysis was performed using the t-test or Mann-Whitney U test to evaluate the differences between the groups, with a P-value of less than 0.05 considered statistically significant. In this study, a total of 122 patients were included, with 53 allocated to the 3DP group and 69 to the control group. The analysis of the morphological measurements of the LA and PV taken from the workstation or direct entity measurement showed no significant difference between the two groups (P > 0.05). However, patients in the 3DP group experienced significantly shorter RFA times (97.03 ± 28.39 compared to 120.51 ± 44.76 min, t = 3.05, P = 0.003), reduced duration of radiation exposure (2.55 [interquartile range 2.01, 3.24] versus 3.20 [2.28, 3.91] min, Z = 3.23, P < 0.001), and shorter modeling times (7.68 ± 1.03 compared to 8.89 ± 1.45 min, t = 5.38, P < 0.001). 3DP technology has the potential to enhance standard RFA practices by reducing the time required for intraoperative interventions and exposure to radiation.

Colchicine Prevents Post-Ablation Atrial Fibrillation Recurrence: A Systematic Review and Meta-Analysis

Catheter ablation for atrial fibrillation (AF) is a commonly performed procedure, however, post-ablation AF recurrence is often observed due to inflammation and oxidative stress. Colchicine is a potent anti-inflammatory agent with conflicting efficacy in preventing post-ablation AF recurrence. A comprehensive literature search of the major bibliographic databases was conducted to retrieve studies comparing colchicine use versus placebo in AF patients post-ablation. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using the DerSimonian-Laird random-effects model. Statistical significance was set at P < 0.05. Six studies were included with 1791 patients (721 in the colchicine group and 1070 in the placebo group). Patients who received colchicine had significantly lower odds of AF recurrence on follow-up (OR, 0.62; 95% CI, 0.48-0.79; P = 0.0001) but had higher gastrointestinal side effects (OR, 2.67; 95% CI, 1.00-7.12; P = 0.05). There were no statistically significant differences in acute pericarditis (OR, 0.54; 95% CI, 0.27-1.05; P = 0.07) or hospitalization (OR, 1.03; 95% CI, 0.73-1.45; P = 0.87). Prophylactic use of colchicine after catheter ablation in patients with AF leads to a reduction in AF recurrence, albeit with increased gastrointestinal side effects. Colchicine use did not lead to a reduction in the rates of pericarditis and hospitalization after ablation. Large randomized controlled trials are necessary to evaluate the efficacy of colchicine in preventing AF recurrence, particularly focusing on the dose and duration of treatment to optimize the side effect profile.

Radiofrequency catheter ablation of atrial fibrillation: A review of techniques

Ablation of atrial fibrillation is a key area of current research. A multitude of techniques have been tested, some of which are poorly evidenced and not recommended in routine clinical practice whilst others are more promising. Additionally, a plethora of issues exist when researching ablation techniques, from control arm ablation strategy to the relevance of outcome measures. In this review article, we discuss these issues in the context of the current evidence base.

Acupuncture-assisted anaesthesia for catheter ablation of atrial fibrillation to reduce the consumption of morphine hydrochloride and postoperative nausea and vomiting (PONV): study protocol for a randomised controlled trial

BACKGROUND

Patients often experience postoperative nausea and vomiting (PONV) after catheter ablation of atrial fibrillation (AF) because of the use of opioids for anaesthesia and analgesia during the procedure. Some clinical trials have demonstrated that acupuncture-assisted anaesthesia (AAA) reduces opioid consumption and prevents PONV. Although several studies have been conducted on AAA, its safety and efficacy in AF catheter ablation remain unclear due to small sample sizes and a paucity of methodologically rigorous designs. Therefore, this trial was designed to evaluate the safety and efficacy of AAA in reducing PONV and morphine hydrochloride consumption during catheter ablation.

METHODS

This single-centre, patient-blinded, randomised, non-penetrating sham-controlled trial will be conducted in China. A total of 100 patients will be randomly assigned to the AAA and conventional anaesthesia (CA) groups in a ratio of 1:1. The patients will receive AAA or CA plus sham acupuncture during catheter ablation and will be followed up for 30 days. The primary outcomes include the total amount of morphine hydrochloride consumed during catheter ablation and PONV within the first 24 hours after the procedure. The secondary outcomes include pain, nausea and vomiting, anxiety, patient's ability to cope during catheter ablation, AF recurrence and quality of life, as assessed using the numeric rating scale. Adverse events will be recorded and their influence will be analysed at the end of the trial.

DISCUSSION

This study will help in evaluating the safety and efficacy of AAA applied for AF catheter ablation in reducing opioid doses during the procedure and the occurrence of PONV.

ETHICS AND DISSEMINATION

The study has been approved by the Medical Ethics Committee of Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine. The results of the study will be published in peer-reviewed journals and presented at conferences if possible.

TRIAL REGISTRATION NUMBER

ChiCTR 2100042646; Chinese Clinical Trial Registry.

Effect of social support on illness perception in patients with atrial fibrillation during "Blanking Period": Mediating role of sense of mastery

AIM

To explore whether sense of mastery can mediate the relationship between social support and illness perception in patients with atrial fibrillation (AF) who were at the "Blanking Period."

DESIGN

A cross-sectional design.

METHODS

405 patients with AF who were at the "Blanking Period" in the Affiliated Hospital of Qingdao University were recruited; they completed a set of questionnaires, including the Perceived Social Support Scale, the Personal Mastery Scale and the Brief Illness Perception Questionnaire.

RESULTS

Social support and sense of mastery were both adversely connected to illness perception. The indirect effect of social support on illness perception through sense of mastery was negative, accounting for 86.04% of the total effect.

CONCLUSION

During the "Blanking Period," better social support and sense of mastery contribute to a positive illness perception of AF patients. Social support also can influence patients' illness perception indirectly via the mediator of sense of mastery.

A contrastive consistency semi-supervised left atrium segmentation model

Accurate segmentation for the left atrium (LA) is a key process of clinical diagnosis and therapy for atrial fibrillation. In clinical, the semantic-level segmentation of LA consumes much time and labor. Although supervised deep learning methods can somewhat solve this problem, a high-efficient deep learning model requires abundant labeled data that is hard to acquire. Therefore, the research on automatic LA segmentation of leveraging unlabeled data is highly required. In this paper, we propose a semi-supervised LA segmentation framework including a segmentation model and a classification model. The segmentation model takes volumes from both labeled and unlabeled data as input and generates predictions of LAs. And then, a classification model maps these predictions to class-vectors for each input. Afterward, to leverage the class information, we construct a contrastive consistency loss function based on these class-vectors, so that the model can enlarge the discrepancy of the inter-class and compact the similarity of the intra-class for learning more distinguishable representation. Moreover, we set the class-vectors from the labeled data as references to the class-vectors from the unlabeled data to relieve the influence of the unreliable prediction for the unlabeled data. At last, we evaluate our semi-supervised LA segmentation framework on a public LA dataset using four universal metrics and compare it with recent state-of-the-art models. The proposed model achieves the best performance on all metrics with a Dice Score of 89.81 %, Jaccard of 81.64 %, 95 % Hausdorff distance of 7.15 mm, and Average Surface Distance of 1.82 mm. The outstanding performance of the proposed framework shows that it may have a significant contribution to assisting the therapy of patients with atrial fibrillation. Code is available at: https://github.com/PerceptionComputingLab/SCC.

Uncertainty-guided symmetric multi-level supervision network for 3D left atrium segmentation in late gadolinium-enhanced MRI

PURPOSE

Atrial fibrillation is a common arrhythmia and requires volumetric imaging to guide the therapy procedure. Late gadolinium-enhanced magnetic resonance imaging (LGE MRI) is an efficient non-invasive technology for imaging the diseased heart. Three-dimensional segmentation of the left atrium (LA) in LGE MRI is a fundamental step for guiding the therapy of patients with atrial fibrillation. However, the low contrast and fuzzy surface of the LA in LGE MRI make accurate and objective LA segmentation challenge. The purpose of this study is to propose an automatic and efficient LA segmentation model based on a convolutional neural network to obtain a more accurate predicted surface and improve the LA segmentation results.

METHODS

In this study, we proposed an uncertainty-guided symmetric multi-level supervision network for 3D LA segmentation in LGE MRI. Firstly, we constructed a symmetric multi-level supervision structure to combine the corresponding features from the encoding and decoding stages to learn the multi-scale representation of LA. Secondly, we formulated the discrepancy of predictions of our model as model uncertainty. Then we proposed an uncertainty-guided objective function to further increase the segmentation accuracy on the surface.

RESULTS

We evaluated our proposed model on the public LA segmentation database using four universal metrics. The proposed model achieved Hausdorff Distance of 11.68 mm, average symmetric surface distance of 0.92 mm, Dice score of 0.92, and Jaccard of 0.85. Compared with state-of-the-art models, our model achieved the best Hausdorff Distance that is sensitive to surface accuracy. For the other three metrics, our model also achieved better or comparable performance.

CONCLUSIONS

We proposed an efficient automatic LA segmentation model that consisted of a symmetric multi-level supervision structure and an uncertainty-guided objective function. Compared to other models, we designed an additional supervision branch in the encoding stage to learn more detailed representations of LA while learning global context information through the multi-level structure of each supervision branch. To address the fuzzy surface challenge of LA segmentation in LGE MRI, we leveraged the model uncertainty to enhance the distinguishing ability of the model on the surface, thereby the predicted accuracy of the LA surface can be further increased. We conducted extensive ablation and comparative experiments with state-of-the-art models. The experiment results demonstrated that our proposed model could handle the complex structure of LA and had superior advantages in improving the segmentation performance on the surface. This article is protected by copyright. All rights reserved.

General anesthesia is not superior to sedation in clinical outcome and cost-effectiveness for ablation of persistent atrial fibrillation

Background

The strategy of anesthesia used during ablation of atrial fibrillation (AF) remains controversial. This study aimed to compare sedation with general anesthesia (GA) for catheter ablation of AF.

Hypothesis

The presence of AF is associated with an increased risk of stroke and heart failure and decreased quality of life and survival.

Methods

We carried out a retrospective single‐centered study with 351 patients undergoing the first ablation procedure for AF under sedation or GA. The main outcome was freedom from recurrence of AF at 1 year. The total time of staying at the ablation laboratory and procedure cost were also calculated.

Results

Freedom from atrial arrhythmia and ablation time did not differ between AF patients under sedation and GA (77.9% vs 79.9% and 42.27 ± 9.84 minutes vs 41.51 ± 9.27 minutes, respectively), while the total procedure time and cost were lower in patients who underwent sedation than GA (171.39 ± 45.09 minutes vs 202.92 ± 43.85 and 8.00 ± 7.02 CNY vs 8.79 ± 11.63 CNY, respectively).

Conclusion

GA is not superior to sedation, in terms of ablation time and freedom from atrial arrhythmia at 1 year, whereas patients with GA had more anesthesia time and procedure cost than sedation.

Attenuation of atrial remodeling by aliskiren via affecting oxidative stress, inflammation and PI3K/Akt signaling pathway

INTRODUCTION

Atrial fibrillation (AF) is the most common type of arrhythmia. Atrial remodeling is a major factor to the AF substrate. The purpose of the study is to explore whether aliskiren (ALS) has a cardioprotective effect and its potential molecular mechanisms on atrial remodeling.

METHODS

In acute experiments, dogs were randomly assigned to Sham, Paced and Paced+aliskiren (10 mg kg^-1) (Paced+ALS) groups, with 7 dogs in each group. Rapid atrial pacing (RAP) was maintained at 600 bpm for 2 h for paced and Paced+ALS groups and atrial effective refractory periods (AERPs), inducibility of AF (AFi) and average duration time (ADT) were measured. In chronic experiments, there were 5 groups: Sham, Sham+ALS, Paced, Paced+ALS and Paced+ALS+PI3K antagonist wortmannin (WM) (70 μg kg^-1 day^-1). RAP at 500 beats/min was maintained for 2 weeks. Inflammation and oxidative stress indicators were measured by ELISA assay, echocardiogram and pathology were used to assess atrial structural remodeling, phosphatidylinositol 3-hydroxy kinase/protein kinase B (PI3K/Akt) signaling pathways were studied by RT-PCR and western blotting to evaluate whether the cardioprotective effect of ALS works through PI3K/Akt signaling pathway.

RESULTS

The electrophysiological changes were observed after 2-h pacing. The AERP shortened with increased AFi and ADT, which was attenuated by ALS (P < 0.05). After pacing for 2 weeks, oxidative stress and inflammation markers in the Paced group were significantly higher than those in the Sham group (P < 0.01) and were reduced by ALS treatment (P < 0.01). The reduced level of antioxidant enzymes caused by RAP was also found to be elevated in ALS-treated group (P < 0.01). The results of pathology and echocardiography showed that RAP can cause atrial enlargement, fibrosis (P < 0.01), and were attenuated in ALS treatment group. The PI3K/Akt signaling pathway were downregulated induced by RAP. ALS could upregulate the PI3K/Akt pathway expression (P < 0.05). Furthermore, the cardioprotective effects in structural remodeling of ALS were suppressed by WM.

CONCLUSIONS

ALS may offer cardioprotection in RAP-induced atrial remodeling, which may partly be ascribed to its anti-inflammatory and anti-oxidative stress action and the regulation of PI3K/Akt signaling pathway.

MediYoga as a part of a self-management programme among patients with paroxysmal atrial fibrillation - a randomised study

BACKGROUND

Paroxysmal atrial fibrillation is associated with impaired health-related quality of life. Yoga has been suggested to improve health-related quality of life among patients with heart failure and hypertension.

AIM

The aim of the study was to evaluate the effects of MediYoga, in respect of health-related quality of life, blood pressure, heart rate, as well as N-terminal pro b-type natriuretic peptide, among patients with symptomatic paroxysmal atrial fibrillation, compared with standard therapy or relaxation.

METHODS

Patients with symptomatic paroxysmal atrial fibrillation, n=132, were stratified for gender and randomised to MediYoga, a relaxation group or a control group, 44 patients per group with a 12-week follow-up. Health-related quality of life, blood pressure, heart rate and N-terminal pro b-type natriuretic peptide were assessed.

RESULTS

After 12 weeks, there were no differences in health-related quality of life between the groups. There were improvements in Short-Form Health Survey bodily pain, general health, social function, mental health and mental component summary scores within the MediYoga group (p=0.014, p=0.037, p=0.029, p=0.030, p=0.019, respectively). No change was seen in the relaxation and control groups. Systolic blood pressure decreased in the MediYoga group (134±18 to 127±13) compared with the control group (126±17 to 127±15, p=0.041); no difference compared with the relaxation group (131±17 to 125±12). Diastolic blood pressure decreased in the MediYoga group (79±9 to 74 ±9) compared with the control group (76±9 to 79±8, p=0.005); no difference compared with the relaxation group (76±9 to 77±8). There were no differences in heart rate and N-terminal pro b-type natriuretic peptide between the groups after 12 weeks.

CONCLUSIONS

MediYoga improves health-related quality of life and decreases blood pressure in patients with paroxysmal atrial fibrillation. MediYoga may be used as a part of a self-management programme among patients with paroxysmal atrial fibrillation.

Combination of doxorubicin liposomes with left atrial appendage radiofrequency catheter ablation to reduce post-ablation recovery of electrical conduction

Aims

To determine whether use of radiofrequency catheter ablation (RFCA) combined with intravenously administered liposomal doxorubicin (L-DOX) facilitates a reduction in the recovery of post-ablation electrical conduction.

Methods

Circumferential ablation was performed on the epicardial surface of the left atrial appendage (LAA) in New Zealand White rabbits, and L-DOX was then administered intravenously. Fluorescence spectrophotometry was used to assess reagent bio-distribution, while Western blots and immunohistochemistry were used to assess the localization of the apoptotic markers Bcl-2, Bax, and cleaved CASP3 in the LAA. Liver, kidney, and cardiac functions were also measured to evaluate the safety of this approach.

Results

At 1 week and 1 month after RFCA, a pacing electrocardiogram could not be detected in most of the rabbits that had received the combined RFCA and L-DOX therapy. L-DOX began to target the LAA on the second day after RFCA. L-DOX treatment increased the apoptosis of cardiomyocytes in the regions peripheral to the necrotic area induced by RFCA. Doxorubicin had some effect on liver and kidney function, but these effects were reversible and did not affect survival.

Conclusion

The present results provide evidence that L-DOX treatment can reduce the recovery of electrical conduction after RFCA therapy owing to L-DOX-induced apoptosis of cardiomyocytes in the ablated area and the proximal transition zone of the LAA.

Cardiac computed tomography previous to atrial fibrillation ablation - effects of technological improvements and protocol optimization

BACKGROUND

Cardiac computed tomography (CT) can provide a precise tridimentional anatomic map and exclude intra-cardiac thrombus. We aimed to access the impact of CT protocol optimization and technological evolution on the contrast and radiation dose as well as on image quality previous to atrial fibrillation (AF) ablation.

METHODS

From a prospective registry of consecutive patients who underwent cardiac CT in a single center, we selected 270 patients in whom the CT was done for evaluation prior to AF ablation and they were distributed in 3 groups: Group1: the first 150 patients included; Group2: the last 60 patients performed with the same CT scanner; Group3: the first 60 exams performed with the new CT scanner. Quality of the protocol was access based on radiation dose, contrast volume used, the use of a second (delayed) acquisition, and on quantitative image quality analisis (signal to noise and contrast to noise ratios; density homogeneity racio between LA and LAA).

RESULTS

We found a significant radiation dose as well as contrast dose reduction between the first and last subgroups (G1: 5,6mSv and 100ml; G2: 1,3mSv and 90ml; G3: 0,6mSv and 65ml). Even though group 3 had less radiation and contrast used it still had better quantitative image quality (signal/noise of 13,5; contrast/noise 14,8; density homogeneity racio of 0,92).

CONCLUSION

Protocol optimization and technology both contributed to significant lower radiation dose and contrast volume used on cardiac CTs prior to AF ablation, without compromising image quality.