Radiofrequency Ablation Procedures Research Articles

Different predictors of AF recurrence after pulmonary vein isolation with cryoballoon and radiofrequency ablation: insights from clinical and electroanatomical mapping data of the NO-PERSAF study

Abstract Background Pulmonary vein isolation (PVI) with cryobaloon ablation (CBA) and radiofrequency ablation (RFA) lead to a similar outcome of freedom from atrial tachyarrhythmia (ATA) during follow-up as showed by the NO-PERSAF study. Analyses of ATA recurrence for these two techniques based on data of electroanatomical mapping (EAM) are scarce from randomized clinical trials. Purpose This study aimed to evaluate and compare clinical outcomes and EAM data recorded in the left atrium (LA) during CBA and RFA procedures in patients with persistent atrial fibrillation (AF). Methods For the NO-PERSAF study, 101 patients (mean 63.2±8.6 years, 80 male, 21 female) with persistent AF (77 persistent AF, 24 long-standing persistent AF) referred to PVI were randomized (1:1) to CBA or RFA and followed for 12 months. A prolonged 3-year follow-up was carried out. EAM was performed by a circular mapping catheter with a 3-dimensional mapping system in all patients. EAM data were recorded and analyzed off-line. The areas of the LA, posterior wall, low-voltage (<0.5mV) and complex fractionated electrogram (cycle length <120 ms) were measured and corrected by body surface area (BSA). EAM data from 90 patients were qualified for further analysis and the others (5 in CBA and 6 in RFA) excluded because of disqualification or technical failure of recording. Correlation between clinical results of 3-year follow-up and the EAM data were analyzed using univariate cox regression. Results After 3-year follow-up, freedom from ATA was achieved in 51 (50.5%) of the 101 patients, 28 (54.9%) out of 51 patients in the CBA group and 23 (46.0%) out of 50 patients in the RFA group and no difference was found (p=0.327). RFA compared with CBA resulted in larger ablation lesions in the LA (23.9% vs. 21.3%; p=0.037) and particularly in the posterior wall (44.2% vs 31.8%; p<0.001). Compared between the patients with and without recurrence, there was no difference with respect to age, gender, AF history, body mass index, heart disease and CHA2DS2-vasc score. For EAM data, the area of the LA and low voltage were significantly higher in ATA recurrent patients in CBA group, but not in RFA group (Table 1). Univariate cox regression analyses suggested that 3-year follow-up outcomes were associated with the size of the LA and the amount of low voltage corrected by BSA. The criteria of the LA area >55 cm2/m2 or low voltage area <19 cm2/m2 could predict ATA recurrence after CBA, but not after RFA procedure (Figure 1). Conclusions The size of the LA and the amount of low voltage corrected by BSA was associated with the outcomes of PVI during follow-up and could be employed as predictors of ATA recurrence for CBA, but not for RFA procedure.Table 1Figure 1K-M curves after CBA and RFA

Pulsed field ablation for complex resistant atrial tachycardia recurring after radiofrequency ablation of persistent atrial fibrillation

Abstract Background There is a limited knowledge on immediate and long-term efficacy of pulsed field ablation (PFA) for residual atrial tachycardia (AT) recurring after persistent atrial fibrillation ablation (AF). Purpose To present immediate and medium-term outcome of PFA (Farapulse) for complex AT recurring after ≥1 radiofrequency ablation (RFA) of primary (longstanding) persistent AF. Methods In 5/2022-10/2023, 81 patients (64±8 years, 19 females) underwent PFA for complex AT in 83 PFA procedures after prior RFA procedure(s); in first (n=21), second (n=33), third (n=23), fourth (n=5), or fifth (n=1) repeat ablation procedure, respectively. Mapping/ablation strategy was directed by the CS activation/entrainment to: 1) no 3D mapping and direct PFA in left atrium (n=67); 2) PFA directly after 3D LA mapping (n=9); 3) PFA following RFA after 3D LA mapping (n=7). AT sources were classified as macroreentry (MRAT) (perimitral, roof-dependent, typical flutter) or localized (LOCAT) in case of smaller reentry or ectopic origin. Results At the procedure onset, persistent AT was present in 58 patients, in the remaining cases AT (n=21) or AF (n=4) were induced. AF eventually occurred at some time of procedure in another 10 patients and was terminated by ablation at LA ridge/CS/LOM region 8x, LA posterior wall 3x, LUPV 1x, RUPV 1x, and RA low lateral wall 1x. Only MRAT, only LOCAT, or both AT types were found at 34 (41%), 35 (42%), and 14 (17%) procedures, respectively. A total of 125 ATs was identified (1, 2, and 3 ATs in 52, 20, and 11 patients). MRAT (n=60) included 32 perimitral ATs, 20 roof-dependent ATs, and 8 typical flutters. LOCAT (n=65) included RUPV source (n=1), LA extraPV sources (n=59), and RA sources (n=5). SR was restored with a 5±7 PFA applications at the site of AF source, total of PFA deliveries was 71±27, and procedure and fluoroscopy times were and 89±37 and 9±5 minutes, respectively. In the 7 patients with initial ineffective 6, 6, 11, 5, 18, 10, and 2 minutes of RFA, the AT was converted into SR by subsequent 1, 4, 1, 13, 4, 24, and 20 PFA applications. All ATs were terminated and noninducibility was achieved in 82 (99%) and 74 (89%) procedures, respectively. In 52 patients with >3 month follow-up, 46 (88%) patients remain in stable SR (41 / 79%) off AAD); 3 and 3 patients have paroxysmal or persistent AT. Conclusion PFA with catheter Farapulse can affect complex/epicardial AT sources resistant to RFA in prior or present ablation procedure; however, there is a certain discrepancy between high efficacy in AT terminating and medium-term clinical outcome.

Ablation of liver tumors : From pre-interventional imaging to post-interventional assessment

The aim of this article is to provide an overview on the most frequently applied image-guided, percutaneous, local ablative techniques for treatment of primary and secondary liver tumors. The technical procedures of microwave ablation (MWA) and radiofrequency ablation (RFA) are presented. The pre-interventional diagnostics, indications and feasibility are also discussed, taking the current national guidelines into consideration. Finally, treatment outcomes and recommendations on post-interventional imaging following local tumor ablation are presented.

Application of Deep Learning for Real-Time Ablation Zone Measurement in Ultrasound Imaging.

The accurate delineation of ablation zones (AZs) is crucial for assessing radiofrequency ablation (RFA) therapy's efficacy. Manual measurement, the current standard, is subject to variability and potential inaccuracies. This study aims to assess the effectiveness of Artificial Intelligence (AI) in automating AZ measurements in ultrasound images and compare its accuracy with manual measurements in ultrasound images. An in vitro study was conducted using chicken breast and liver samples subjected to bipolar RFA. Ultrasound images were captured every 15 s, with the AI model Mask2Former trained for AZ segmentation. The measurements were compared across all methods, focusing on short-axis (SA) metrics. We performed 308 RFA procedures, generating 7275 ultrasound images across liver and chicken breast tissues. Manual and AI measurement comparisons for ablation zone diameters revealed no significant differences, with correlation coefficients exceeding 0.96 in both tissues (p < 0.001). Bland-Altman plots and a Deming regression analysis demonstrated a very close alignment between AI predictions and manual measurements, with the average difference between the two methods being -0.259 and -0.243 mm, for bovine liver and chicken breast tissue, respectively. The study validates the Mask2Former model as a promising tool for automating AZ measurement in RFA research, offering a significant step towards reducing manual measurement variability.

Treatment of Warthin's Tumors of the Parotid Gland With Radiofrequency Ablation: A Systematic Review of the Current Literature.

Objective: Warthin's tumors of the parotid gland can be safely observed. Definitive treatment usually requires parotidectomy under general anesthesia. The decision to operate on Warthin's tumors of the parotid gland can be complicated in patients who wish to avoid risks of surgery and general anesthesia. This systematic review explores the potential of radiofrequency ablation (RFA) as a minimally invasive alternative. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) model was used to collect 3 relevant studies that focused on RFA treatment for Warthin's tumors. The cumulative averages for tumor size and cosmetic scores were then quantified for patients with Warthin's tumors who underwent RFA therapy. The PRISMA systematic review method was employed to the PubMed and EMBASE databases. The comprehensive search term "Warthin Tumor Treatment" yielded 1299 articles from the years 1955 to 2023, 3 of which met inclusion criteria and were then selected. Results: The 3 quantitative studies collectively assessed 37 patients with Warthin's tumors treated with RFA. Patients experienced an average tumor size reduction of 85.03% at 12 months post-RFA. There were minimal complications associated with RFA in these patients. Conclusion: This study suggests that RFA is an alternative to parotidectomy for the symptomatic treatment of Warthin's tumors. RFA procedures demonstrated substantial tumor size reduction with few complications. However, further meta-analysis and comparison with alternative treatments is warranted to establish RFA's role in treatment of Warthin's tumors. The study is limited by its reliance on only 2 databases and a lack of comprehensive examination of different RFA settings.

Does radiofrequency ablation procedural data improve the accuracy of identifying atrial fibrillation recurrence?

Radiofrequency ablation (RFA) using the CARTO 3D mapping system is a common approach for pulmonary vein isolation to treat atrial fibrillation (AF). Linkage between CARTO procedural data and patients' electronical health records (EHR) provides an opportunity to identify the ablation-related parameters that would predict AF recurrence. The objective of this study is to assess the incremental accuracy of RFA procedural data to predict post-ablation AF recurrence using machine learning model. Procedural data generated during RFA procedure were downloaded from CARTONET and linked to deidentified Mercy Health EHR data. Data were divided into train (70%) and test (30%) data for model development and validation. Automate machine learning (AutoML) was used to predict 1 year AF recurrence, defined as a composite of repeat ablation, electrical cardioversion, and AF hospitalization. At first, AutoML model only included Patients' demographic and clinical characteristics. Second, an AutoML model with procedural variables and demographical/clinical variables was developed. Area under receiver operating characteristic curve (AUROC) and net reclassification improvement (NRI) were used to compare model performances using test data. Among 306 patients, 67 (21.9%) patients experienced 1-year AF recurrence. AUROC increased from 0.66 to 0.78 after adding procedural data in the AutoML model based on test data. For patients with AF recurrence, NRI was 32% for model with procedural data. Nine of 10 important predictive features were CARTO procedural data. From CARTO procedural data, patients with lower contact force in right inferior site, long ablation duration, and low number of left inferior and right roof lesions had a higher risk of AF recurrence. Patients with persistent AF were more likely to have AF recurrence. The machine learning model with procedural data better predicted 1-year AF recurrence than the model without procedural data. The model could be used for identification of patients with high risk of AF recurrence post ablation.

New radiofrequency ablation procedure for selective reduction in complicated monochorionic twin or triplet pregnancy using multistep, incremental expansion technique.

Radiofrequency ablation (RFA) is the preferred approach for selective reduction in complex monochorionic (MC) multiple pregnancies owing to the ease of operation and minimal invasiveness. To optimize the RFA technique and reduce the risk of adverse pregnancy outcome resulting from the heat-sink effect of RFA therapy, we used an innovative RFA method, in which an electrode needle was expanded incrementally and stepwise. This study aimed to assess the efficacy and safety profile of this novel multistep incremental expansion RFA method for selective fetal reduction in MC twin and triplet pregnancies. This was a single-center retrospective cohort study of all MC multiple pregnancies undergoing RFA between March 2016 and October 2022 at our center. The multistep RFA technique involved the use of an expandable needle, which was gradually expanded during the RFA procedure until cessation of umbilical cord blood flow was achieved. The needle used for the single-step RFA method was fully extended from the start of treatment. In total, 132 MC multiple pregnancies underwent selective reduction using RFA, including 50 cases undergoing multistep RFA and 82 cases undergoing single-step RFA. The overall survival rates were not significantly different between the multistep and single-step RFA groups (81.1% vs 72.3%; P = 0.234). Similarly, the rates of preterm prelabor rupture of the membranes within 2 weeks after RFA, procedure-related complications, spontaneous preterm delivery and pathological findings on cranial ultrasound, as well as gestational age at delivery and birth weight, did not differ between the two groups. However, there was a trend towards a prolonged procedure-to-delivery interval following multistep RFA compared with single-step RFA (median, 109 vs 99 days; P = 0.377). Moreover, the fetal loss rate within 2 weeks after RFA in the multistep RFA group was significantly lower than that in the single-step RFA group (10.0% vs 24.4%; P = 0.041). The median ablation time was shorter (5.3 vs 7.8 min; P < 0.001) and the median ablation energy was lower (10.2 vs 18.0 kJ; P < 0.001) in multistep compared with single-step RFA. There were no significant differences in neonatal outcomes following multistep vs single-step RFA. Overall survival rates were similar between the two RFA methods. However, the multistep RFA technique was associated with a lower risk of fetal loss within 2 weeks after RFA. The multistep RFA technique required significantly less ablation energy and a shorter ablation time compared with single-step RFA in selective fetal reduction of MC twin and triplet pregnancies. Additionally, there was a trend towards a prolonged procedure-to-delivery interval with the multistep RFA technique. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Short time effects of two radiofrequency ablation methods on hypertrophic obstructive cardiomyopathy.

Radiofrequency ablation has been applied for the treatment of hypertrophic obstructive cardiomyopathy (HOCM). The two known procedures are percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) and endocardial radiofrequency septal ablation (ERSA). This study presents a retrospective analysis of the PIMSRA and ERSA procedures in patients with drug-refractory HOCM. A total of 28 patients participated in the study, with 12 receiving PIMSRA and 16 receiving ERSA. The objective of our study was to compare the short-term effects of these two radiofrequency ablation procedures. At the 30-day follow-up, the PIMSRA group demonstrated a greater reduction in left ventricular outflow tract peak gradient at rest compared to the ERSA group (22.25 [16.72] mmHg versus 47.75 [21.94] mmHg) (p < .01). The values for the PIMSRA group decreased from 99.33 (32.00) mmHg to 22.25 (16.72) mmHg (p < .01), while the ERSA group decreased from 97.75 (30.24) mmHg to 47.75 (21.94) mmHg (p < .01). Only the PIMSRA group exhibited a decrease in mitral regurgitation (MR). The area of MR decreased from 10.13 (4.12) mm2 to 3.65 (2.80) mm2 in the PIMSRA group (p < .01). Additionally, the PIMSRA group experienced reductions in left atrial diameter (LAD) and left ventricular ejection fraction (LVEF)%. The values for LAD changed from 43.58 (7.53) mm to 37.08 (6.92) mm (p = .03), and the values for LVEF% decreased from 65.75 (6.12) pg/mL to 60.83 (4.06) pg/mL (p = .03). In terms of the two types of radiofrequency ablation methods used in HOCM, it has been observed that PIMSRA demonstrates a more favorable early treatment effect compared to ERSA.

Robust, high-density lesion mapping in the left atrium with near-infrared spectroscopy.

Radiofrequency ablation (RFA) procedures for atrial fibrillation frequently fail to prevent recurrence, partially due to limitations in assessing extent of ablation. Optical spectroscopy shows promise in assessing RFA lesion formation but has not been validated in conditions resembling those in vivo. Catheter-based near-infrared spectroscopy (NIRS) was applied to porcine hearts to demonstrate that spectrally derived optical indices remain accurate in blood and at oblique incidence angles. Porcine left atria were ablated and mapped using a custom-fabricated NIRS catheter. Each atrium was mapped first in phosphate-buffered saline (PBS) then in porcine blood. NIRS measurements showed little angle dependence up to 60deg. A trained random forest model predicted lesions with a sensitivity of 81.7%, a specificity of 86.1%, and a receiver operating characteristic curve area of 0.921. Predicted lesion maps achieved a mean structural similarity index of 0.749 and a mean normalized inner product of 0.867 when comparing maps obtained in PBS and blood. Catheter-based NIRS can precisely detect RFA lesions on left atria submerged in blood. Optical parameters are reliable in blood and without perpendicular contact, confirming their ability to provide useful feedback during in vivo RFA procedures.

Computer simulation-based nanothermal field and tissue damage analysis for cardiac tumor ablation.

Radiofrequency ablation is a nominally invasive technique to eradicate cancerous or non-cancerous cells by heating. However, it is still hampered to acquire a successful cell destruction process due to inappropriate RF intensities that will not entirely obliterate tumorous tissues, causing in treatment failure. In this study, we are acquainted with a nanoassisted RF ablation procedure of cardiac tumor to provide better outcomes for long-term survival rate without any recurrences. A three-dimensional thermo-electric energy model is employed to investigate nanothermal field and ablation efficiency into the left atrium tumor. The cell death model is adopted to quantify the degree of tissue injury while injecting the Fe3O4 nanoparticles concentrations up to 20% into the target tissue. The results reveal that when nanothermal field extents as a function of tissue depth (10mm) from the electrode tip, the increasing thermal rates were approximately 0.54362%, 3.17039%, and 7.27397% for the particle concentration levels of 7%, 10%, and 15% compared with no-particle case. In the 7% Fe3O4 nanoparticles, 100% fractional damage index is achieved after ablation time of 18s whereas tissue annihilation approach proceeds longer to complete for no-particle case. The outcomes indicate that injecting nanoparticles may lessen ablation time in surgeries and prevent damage to adjacent healthy tissue.

Coronary Artery Bypass Grafting for Refractory Ventricular fibrillation after the Release of the Aortic Cross-Clamp in Patients Undergoing Aortic Valve Replacement: A Case Report

Background: Ventricular fibrillation (VF) is a known complication after the release of the aortic cross-clamp (ACC) during cardiopulmonary bypass (CPB) surgery. Various factors contribute to persistent refractory VF, making its management challenging. This case report describes the successful treatment of postoperative refractory VF by coronary artery bypass grafting (CABG) in a patient undergoing aortic valve replacement (AVR) with ACC release. Case Presentation: A 52-year-old woman with a history of hypertension and ischemic cerebral infarction presented with symptoms of chest tightness, dyspnoea and palpitations. She underwent a modified maze procedure of radiofrequency ablation, mitral repair, left atrial appendage closure and mechanical AVR under a CPB procedure. Following the ACC release, the patient experienced recurrent VF that was unresponsive to standard interventions such as lidocaine, amiodarone and direct current shocks. The suspicion of right coronary artery (RCA) insufficiency led to the decision to perform CABG using the great saphenous vein. After the CABG procedure, the patient's heart rhythm gradually returned to sinus rhythm, and she had an uneventful recovery. Discussion and Conclusions: Refractory VF after the ACC release can pose diagnostic and treatment challenges. In this case, RCA insufficiency was suspected as the cause of refractory VF. The absence of blood flow in the proximal RCA and the presence of distal blood return during cardiac surface exploration supported this suspicion. Coronary artery bypass grafting using the great saphenous vein successfully restored normal sinus rhythm, confirming the diagnosis. This case emphasises the importance of considering coronary artery stenosis or occlusion as a potential cause of refractory VF after the ACC release during CPB, with CABG serving as a viable alternative treatment.

Safety of ventricular arrhythmia radiofrequency ablation with half-normal saline irrigation.

Failure of radiofrequency (RF) ablation of ventricular arrhythmias is often due to inadequate lesion size. Irrigated RF ablation with half-normal saline (HNS) has the potential to increase lesion size and reduce sodium delivery to the patient if the same volume of RF irrigant were used for normal saline (NS) and HNS but could increase risks related to steam pops and lesion size. This study aims to assess periprocedural complications and acute ablation outcome of ventricular arrhythmias ablation with HNS. Prospective assessment of outcomes was performed in 1024 endocardial and/or epicardial RF ablation procedures in 935 consecutive patients (median age 64 years, 71.2% men, 73.4% cardiomyopathy, 47.2% sustained ventricular tachycardia). Half-normal saline was selected at the discretion of the treating physician. Radiofrequency ablation power was generally titrated to a ≤15 Ω impedance fall with intracardiac echocardiography monitoring. Half-normal saline was used in 900 (87.9%) and NS in 124 (12.1%) procedures. Any adverse event within 30 days occurred in 13.0% of patients treated with HNS RF ablation including 4 (0.4%) strokes/transient ischaemic attacks and 34 (3.8%) pericardial effusions requiring treatment (mostly related to epicardial access). Two steam pops with perforation required surgical repair (0.2%). Patients who received NS irrigation had less severe disease and arrhythmias. In multivariable models, adverse events and acute success of the procedure were not related to the type of irrigation. Half-normal saline irrigation RF ablation with power guided by impedance fall and intracardiac echocardiography has an acceptable rate of complications and acute ablation success while administering half of the saline load expected for NS irrigation.

Distinguishing cardiac catheter ablation energy modalities by applying natural language processing to electronic health records.

Aim: Catheter ablation is used to treat symptomatic atrial fibrillation (AF) and is performed using either cryoballoon (CB) or radiofrequency (RF) ablation. There is limited real world data of CB and RF in the USas healthcare codes are agnostic of energy modality. An alternative method is to analyze patients' electronic health records (EHRs) using Optum's EHR database. Objective: To determine the feasibility of using patients' EHRs with natural language processing (NLP) to distinguish CB versus RF ablation procedures. Data Source: Optum® de-identified EHRdataset, Optum® Cardiac Ablation NLP Table. Methods: This was a retrospective analysis of existing de-identified EHR data. Medical codes were used to create an ablation validation table. Frequency analysis was used to assess ablation procedures and their associated note terms. Two cohorts were created (1) index procedures, (2) multiple procedures. Possible note term combinations included (1) cryoablation (2) radiofrequency (3) ablation, or (4) both. Results: Of the 40,810 validated cardiac ablations, 3777 (9%) index ablation procedures had available and matching NLP note terms. Of these, 22% (n=844) were classified as ablation, 27% (n= 1016) as cryoablation, 49% (n=1855) as radiofrequency ablation, and 1.6% (n=62) as both. In the multiple procedures analysis, 5691 (14%) procedures had matching note terms. 24% (n=1362) were classified as ablation, 27% as cryoablation, 47% as radiofrequency ablation, and 2% as both. Conclusion: NLP has potential to evaluate the frequency of cardiac ablation by type, however, for this to be a reliable real-world data source, mandatory data entry by providers and standardized electronic health reporting must occur.

Predicting spatio-temporal radiofrequency ablation temperature using deep neural networks

Radiofrequency ablation (RFA) of the medial branch nerve is a widely used therapeutic intervention for facet joint pain. However, denervation of the multifidus muscle is an inevitable consequence of RFA. New ablation techniques with the potential to prevent muscle denervation can be designed using computational simulations. However, depending on the complexity of the model, they could be computationally expensive. As an alternative approach, deep neural networks (DNNs) can be used to predict tissue temperature during RFA procedure. The objective of this paper is to predict the tissue spatial and temporal temperature distributions during RFA using DNNs. First, finite element (FE) models with a range of distances between the probes were run to obtain the temperature readings. The measured temperatures were then used to train the DNNs that predict the spatio-temporal temperature distribution within the tissue. Finally, a separate data obtained from FE simulations were used to test the efficacy of the network. The results presented in this paper demonstrate that the network can achieve an error rate as low as 0.05%, accompanied by a 92% reduction in time compared to FE simulations. The approach proposed in this study will play a major role in the design of new RFA treatments for facet joint pain.

Impact of diagnosis-to-ablation time on clinical outcomes in patients with early-onset atrial fibrillation.

Evidence was lacking for the early choice of radiofrequency ablation (RFA) among patients with early-onset atrial fibrillation (AF). This study aimed to explore whether earlier RFA was associated with better clinical outcomes among early-onset AF patients. Patients, who were diagnosed with AF before 45 years and underwent their first RFA procedures at baseline of the China Atrial Fibrillationregistry, were enrolled and divided into four diagnosis-to-ablation time (DAT) groups: DAT ≤ 1 year, 1 year < DAT ≤ 3 years, 3 years < DAT ≤ 6 years, and DAT > 6 years. Another group of nonablation patients, who were newly diagnosed with AF and younger than 45 years, were also included. Adjusted associations of groups with composite cardiovascular events (cardiovascular death, embolism, major hemorrhages, or cardiac rehospitalization) or recurrent AF were analyzed using Cox proportional hazards models. Among 1694 patients who underwent their first RFA at enrollment, incidences of composite cardiovascular outcomes were increasing with extension of DAT (DAT ≤ 1 year: 6.1/100 person-years, 1 year < DAT ≤ 3 years: 7.9/100 person-years, 3 years < DAT ≤ 6 years: 7.6/100 person-years, DAT > 6 years: 10.5/100 person-years; p < .001). In comparison with DAT > 6 years group, theDAT ≤ 1 year group was associated with reduced risk of cardiovascular events (adjusted hazard ratio, HR[95%confidence interval,CI] = 0.64 [0.47-0.87], p = .005) and AF recurrence (adjusted HR[95% CI] = 0.70 [0.57-0.88], p = .002). Associations remained similar after stratified by AF types. Compared to nonablation group (n = 413), DAT ≤ 1year patients tended to show lower cardiovascular risk (adjusted HR[95% CI] = 0.78 [0.58-1.05], p = .099) and lower risk of recurrent AF (adjusted HR[95% CI] = 0.46 [0.38-0.55], p < .001). A shorter DAT was associated with a lower risk of cardiovascular events and recurrent AF for early-onset AF patients.

One-year clinical outcomes and the impact of procedural configurations in patients with left atrial appendage occlusion

Abstract Background To evaluate the long-term clinical performance, the impact of procedural configurations and post-procedure medications in atrial fibrillation patients with percutaneous left atrial appendage occlusion (LAAO). Methods The RECORD study was a prospective, all-comers registry conducted in 39 Chinese centers that consecutively enrolling patients who received LAAO between 1st April 2019 and 31st October 2020 with minimum inclusion and exclusion criteria. Events including any death, any stroke, systemic embolism and bleeding event were collected at 1 year and adjudicated by an independent clinical event committee. Cox proportional hazard models with multivariable adjustments were applied to estimate hazard ratios (HRs) for each outcome. Results Of the 3,096 participants, 3,082 successfully received an LAAO implant and 3,013 (97.8%) completed the 1-year follow-up. Participants had a high risk of stroke (mean CHA2DS2-VASc score of 4.0) and a moderate-to-high risk of bleeding (mean HAS-BLED score of 2.4). Local anesthetic was performed in 1,287 (41.6%) patients and fluoroscopy guidance in 492 (16.0%) patients. In 1295 (42.0%) cases, one-stage combination procedures of LAAO and radiofrequency ablation or cryoablation (CA) were performed. At 1 year, the composite ischemic endpoint of death, stroke, and systemic embolism occurred in 133 (4.51%) patients. Any life-threatening, disabling or major bleeding events occurred in 71 (2.36%) patients. There was no significant association between the type of anesthesia (general versus local), modality of image guidance (TEE, ICE, or fluoroscopy) with the ischemic or bleeding events. Combination procedures of LAAO plus CA was associated with a significantly lower rate of death, stroke, or systemic embolism than performing LAAO only (3.5% versus 5.2%, HRadjusted:0.69, 95%CI:0.48-0.98, P=0.041). The commonest antithrombotic strategy was OAC | APT | APT (38.1%; corresponded to medication prescribed at discharge | 45 days | 6 months), followed by OAC | OAC | APT (27.0%). Compared with OAC | APT | APT, the OAC | OAC | APT group was associated with a higher risk of life-threatening, disabling or major bleeding (1.2% versus 2.5%, HRadjusted:0.50, 95%CI: 0.25-0.99, P=0.47); whereas the risk of death, stroke and SE was numerically similar (2.9% versus 3.0%, HRadjusted:1.05, 95%CI: 0.61-1.78, P=0.867). There was no significant difference between OAC | APT | APT and OAC+APT | APT | APT groups regarding ischemic events; however, in patients with HAS-BLED ≥ 3, OAC | APT | APT was associated with lower rates of life-threatening, disabling or major bleeding events (1.1% versus 4.8%, HRadjusted:4.55, 95%CI: 1.31-15.81, P=0.017). Conclusion In Chinese centers, patients with a WATCHMAN LAAO device had low rates of ischemic and bleeding events at 1 year. One-stage combination procedures of LAAO and catheter ablation was associated with a significantly lower rate of ischemic events than performing LAAO only.Procedural configurations to outcomesPost-LAAO antithrombotic medications

Comparative Effectiveness of Various Radiofrequency Ablation Catheters in the Ablation of Typical Atrial Flutter.

Although ablation of typical atrial flutter (AFL) can be easily achieved with radiofrequency energy (RF), no studies compare the effectiveness of different ablation catheters. Our study aimed to compare the efficacy of various types of ablation catheters in treating typical AFL. We analyzed patients with AFL who underwent RF ablation by a single operator at our institution. Successful ablation was evidenced by a bidirectional conduction block (trans-isthmus conduction time ≥ 130ms or double potentials ≥ 90ms). Logistic regression was used to compare success rate and linear regression to compare lesion time. Out of 222 patients, only six did not meet the success criteria (2.7%). The catheters used were non-irrigated, large-tip, internally irrigated (Chili II Boston Scientific), and externally irrigated (non-force-sensing) catheters (Cool Path, Abbott). An externally irrigated force-sensing catheter (TactiCath, Abbott) was used with > 10 gm of force and (LPLD) setting (30 W- 45°C- 60s), and high-power short-duration (HPSD) setting (50 W- 43°C - 12s). No complications were encountered. The catheter type had no statistically significant association with ablation success. With the use of externally irrigated catheter with contract force-sensing and HPSD settings, statistically significantly shortening of lesion time was achieved 758.3s, [CI - 1128.29, - 388.35s] followed by LPLD by 419.0s [CI - 808.49, - 29.47s]. The typical atrial flutter radiofrequency ablation procedure had a high success rate, which was not influenced by the type of ablation catheter. Contact force ablation catheter and HPSD are associated with shorter total lesion time.

Complications of transvaginal radiofrequency ablation of fibroids: A 5-year experience

IntroductionTransvaginal radiofrequency ablation is a relatively noninvasive approach for the treatment of fibroids in patients who do not wish to undergo conventional surgery. Information on potential complications of this novel technique is very scarce. MethodsRetrospective, descriptive, epidemiological study of 115 patients who underwent transvaginal radiofrequency ablation of fibroids and for whom complications were recorded. ResultsWe performed 115 transvaginal radiofrequency ablation procedures, we recorded a total of 11 complications (9.6%; 95% CI, 3.8–14.8). Of these, 8 (7.0%) were classified as Clavien-Dindo type I, 1 (0.9%,) as type II, and 2 (1.7%) as type IIIb (severe). No other complications were recorded in a year follow-up. ConclusionTransvaginal radiofrequency ablation is a treatment option that makes it possible to treat fibroids that are difficult to manage using other techniques. Few associated complications have been described, and most of them are mild.

SAT307 Intraoperative Radiofrequency Ablation Of An Unresectable Abdominal Paraganglioma Promoted Objective Tumor Response And Complete Biochemical Remission

Abstract Disclosure: I.P. de Magalhães: None. B.S. Boger: None. N.L. Gomes: None. G.L. Martins: None. L.A. Bomfim Jr: None. G.F. Fagundes: None. A.F. Afonso: None. J. Petenuci: None. F.M. Coelho: None. V. Srougi: None. F.Y. Tanno: None. J.L. Chambo: None. A. Latronico: None. M.B. Fragoso: None. A.O. Hoff: None. B.B. Mendonca: None. M.R. Menezes: None. M.Q. Almeida: None. Background: Metastatic pheochromocytoma and paraganglioma (PPGL) are incurable neuroendocrine tumors. Few reports demonstrated the efficacy of radiofrequency ablation (RFA) in achieving tumor control of metastatic lesions (usually &amp;lt;3 cm). However, intraoperative RFA of large and unresectable primary PPGLs was not previously demonstrated. Case Report: A 31-year-old male patient was diagnosed with symptoms of catecholamine excess, high levels of plasma metanephrines and a 9 cm retroperitoneal tumor. The patient underwent an open laparotomy, which revealed unresectable disease. Anatomopathological and immunohistochemical analysis was compatible with the diagnosis of paraganglioma. The patient was treated with 13 cycles of cytotoxic chemotherapy (cyclophosphamide, vincristine and dacarbazine) without objective tumor response by RECIST. Then, he was referred to our Institution for evaluation of additional therapies. Blood pressured was well controlled with doxazosin 16 mg/d, propranolol 40 mg/d and losartan 100 mg/d. A magnetic resonance imaging (MRI) revealed an extensive retroperitoneal mass with 9.0 x 8.6 x 6.0 cm (208 ml) that involved the inferior portion of the vein inferior vena cava, inferior mesenteric artery and infrarenal aorta. Biochemical evaluation demonstrated very high levels of plasma normetanephrine (20.2 nmol/L; normal range &amp;lt;0.9 nmol/L) and normal metanephrine level (0.2 nmol/L; &amp;lt;0.5 nmol/L). The genetic investigation showed the germline pathogenic variant c.1591delC (p.Ser198Alafs*22) in SDHB gene. I131-metaiodobenzylguanidine scintigraphy was negative and Ga68-dotatate PET-CT scan displayed a high uptake in the abdominal mass without metastatic disease. Unfortunately, lutetium177 treatment is not available in our Institution. Due to the lack of alternative therapies, we proposed a debulking open laparotomy with intraoperative RFA in the remaining tumoral lesion. Nevertheless, the tumor did not present a clear cleavage plane with the large vessels and had a large caliber intratumoral vasculature. Intraoperative RFA was performed by a very experienced team (interventional radiologist and anesthesiologist to control blood pressure during the procedure). After 2 months, the dose of doxazosin decreased from 16 mg to 8 mg (50% reduction), plasma normetanephrines dropped to 4.6 nmol/L (79%), and the largest tumor diameter at MRI reduced to 6.8 cm (88.8 ml, 57% reduction). After 7 months of the RFA procedure, the tumor continues shrinking (4.8 cm, 45 ml, 78% reduction) and plasma normetanephrine completely normalized. Conclusion: This is the first report of intraoperative RFA of a large primary unresectable paraganglioma. The patient presented a striking clinical success, complete biochemical remission and an objective tumor response. Support: Sao Paulo Research Foundation (FAPESP) grant 2019/15873-6 (to M.Q. Almeida). Presentation: Saturday, June 17, 2023

Radiofrequency ablation for thyroid Bethesda III nodules: preliminary results.

The purpose of this study was to evaluate the feasibility of radiofrequency ablation (RFA) for thyroid nodules with cytological atypia of undetermined significance or follicular lesion of undetermined significance (AUS/FLUS, Bethesda III). A total of 28 adults presenting with 30 initial Bethesda III nodules underwent thyroid RFA at a single medical center. Thyroid nodules with Bethesda IV or V according to the second aspiration were excluded. All RFA procedures were performed using the free-hand, 'moving-shot' technique under local anesthesia. Clinical features and demographics, RFA details, nodule volume reduction rate (VRR), and complications were analyzed. The mean age of patients was 47.6 years, 82.1% of whom were females. Mean nodule volumes at pre-RFA, and at 6 months and 12 months post-RFA were 7.92, 2.42, and 1.25 mL, respectively, with a VRR of 77.9% at 6 months, and 87.4% at 12 months. Post-RFA complications were noted in two patients, one with transient vocal cord palsy and another with isthmus minor rupture. RFA may be another safe alternative except for active surveillance or surgical excision for AUS/FLUS nodules with low-suspicion Thyroid Imaging Reporting and Data System features for patients who are unsuitable or strongly refuse surgery. Long-term results remain uncertain, thus further follow-up study is necessary.