Functional substrate mapping of atrium in patients with atrial scar: A novel method to predict critical isthmus of atrial tachycardia.

Atrial tachycardia (AT) is a common rhythm disorder, especially in patients with atrial structural abnormalities. Although voltage mapping can provide a general picture of structural alterations which are mainly secondary to prior ablations, surgery or pressure/volume overload, data is scarce regarding the functional characteristics of low voltage regions in the atrium to predict critical isthmus of ATs. Recently, functional substrate mapping (FSM) emerged as a potential tool to evaluate the functionality of structurally altered regions in the atrium to predict critical sites of reentry. Current evidence suggested a clear association between deceleration zones of isochronal late activation mapping (ILAM) during sinus/paced rhythm and critical isthmus of reentry in patients with left AT. Therefore, these areas seem to be potential ablation targets even not detected during AT. Furthermore, abnormal conduction detected by ILAM may also have a role to identify the potential substrate and predict atrial fibrillation outcome after pulmonary vein isolation. Despite these promising findings, the utility of such an approach needs to be evaluated in large-scale comparative studies. In this review, we aimed to share our experience and review the current literature regarding the use of FSM during sinus/paced rhythm in the prediction of re-entrant ATs and discuss future implications and potential use in patients with atrial low-voltage areas.

Enhancing precision in lung tumor ablation through innovations in CT-guided technique and angle control.

BACKGROUND: This retrospective study aimed to evaluate the precision and safety outcomes of image-guided lung percutaneous thermal ablation (LPTA) methods, focusing on radiofrequency ablation (RFA) and microwave ablation (MWA). The study utilized an innovative angle reference guide to facilitate these techniques in the treatment of lung tumors. METHODS: This study included individuals undergoing LPTA with the assistance of laser angle guide assembly (LAGA) at our hospital between April 2011 and March 2021. We analyzed patient demographics, tumor characteristics, procedure details, and complications. Logistic regressions were employed to assess risk factors associated with complications. RESULTS: A total of 202 patients underwent ablation for 375 lung tumors across 275 sessions involving 495 ablations. Most procedures used RFA, especially in the right upper lobe, and the majority of ablations were performed in the prone position (49.7%). Target lesions were at a median depth of 39.3 mm from the pleura surface, and remarkably, 91.9% required only a single puncture. Complications occurred in 31.0% of ablations, with pneumothorax being the most prevalent (18.3%), followed by pain (12.5%), sweating (6.5%), fever (5.0%), cough (4.8%), hemothorax (1.6%), hemoptysis (1.2%), pleural effusion (2.0%), skin burn (0.6%), and air emboli (0.2%). The median procedure time was 21 min. Notably, smoking/chronic obstructive pulmonary disease emerged as a significant risk factor for complications. CONCLUSION: The LAGA-assisted LPTA enhanced safety by improving accuracy and reducing risks. Overall, this investigation contributes to the ongoing efforts to refine and improve the clinical application of these thermal ablation techniques in the treatment of lung tumors.

Catheter ablation for non-paroxysmal atrial fibrillation. A review.

Atrial fibrillation (AF), the most common cardiac arrhythmia is associated with increased morbidity and mortality. The higher mortality is due to the risk of heart failure and cardioembolic events. This in-depth review focuses on the strategies and efficacy of catheter ablation for non-paroxysmal atrial fibrillation. The main medical databases were searched for contemporary studies on catheter ablation for non-paroxysmal AF. Catheter ablation is currently proven to be the most effective treatment for AF and consists of pulmonary vein isolation as the cornerstone plus additional ablations. In terms of SR maintenance, it is less effective in non-paroxysmal AF than in paroxysmal patients. but the clinical benefit in non-paroxysmal patients is substantially higher. Since pulmonary vein isolation is ineffective, a variety of techniques have been developed, e.g. linear ablations, ablation of complex atrial fractionated electrograms, etc. Another paradox consists in the technique of catheter ablation. Despite promising results in early observation studies, further randomized studies have not confirmed the initial enthusiasm. Recently, a new approach, pulsed-field ablation, appears promising. This is an in-depth summary of current technologies and techniques for the ablation of non-paroxysmal AF. We discuss the benefits, risks and implications in the treatment of patients with non-paroxysmal AF.

Distributions and number of drivers on real-time phase mapping associated with successful atrial fibrillation termination during catheter ablation for non-paroxysmal atrial fibrillation.

BACKGROUND: Real-time phase mapping (ExTRa™) is useful in determining the strategy of catheter ablation for non-paroxysmal atrial fibrillation (AF). This study aimed to investigate the features of drivers of AF associated with its termination during ablation. METHODS: Thirty-six patients who underwent catheter ablation for non-paroxysmal AF using online real-time phase mapping (ExTRa™) were enrolled. A significant AF driver was defined as an area with a non-passively activated ratio of ≥ 50% on mapping analysis in the left atrium (LA). All drivers were simultaneously evaluated using a low-voltage area, complex fractionated atrial electrogram (CFAE), and rotational activity by unipolar electrogram analysis. The electrical characteristics of drivers were compared between patients with and without AF termination during the procedure. RESULTS: Twelve patients achieved AF termination during the procedure. The total number of drivers detected on the mapping was significantly lower (4.4 ± 1.6 vs. 7.4 ± 3.8, p = 0.007), and the drivers were more concentrated in limited LA regions (2.8 ± 0.9 vs. 3.9 ± 1.4, p = 0.009) in the termination group than in the non-termination group. The presence of drivers 2-6 with limited (≤ 3) LA regions showed a tenfold increase in the likelihood of AF termination, with 83% specificity and 67% sensitivity. Among 231 AF drivers, the drivers related to termination exhibited a greater overlap of CFAE (56.8 ± 34.1% vs. 39.5 ± 30.4%, p = 0.004) than the non-related drivers. The termination group showed a trend toward a lower recurrence rate after ablation (p = 0.163). CONCLUSIONS: Rotors responsible for AF maintenance may be characterized in cases with concentrated regions and fewer drivers on mapping.

Ablation techniques or active surveillance compared to surgical resection in patients with low-risk papillary thyroid cancer: a systematic review and meta-analysis.

BACKGROUND: The global prevalence of thyroid cancer is on the rise. About one-third of newly diagnosed thyroid cancer cases comprise low-risk papillary thyroid cancer (1.5 cm or more minor). While surgical removal remains the prevailing approach for managing low-risk papillary thyroid cancer (LPTC) in patients, other options such as active surveillance (AS), radiofrequency ablation (RFA), microwave ablation (MWA), and laser ablation (LA) are also being considered as viable alternatives. This study evaluated and compared surgical thyroid resection (TSR) versus non-surgical (NS) methods for treating patients with LPTC. METHODS: The study encompassed an analysis of comparisons between surgical thyroid resection (TSR) and alternative approaches, including active surveillance (AS), radiofrequency ablation (RFA), microwave ablation (MWA), or laser ablation (LA). The focus was on patients with biopsy-confirmed low-risk papillary thyroid cancer (LPTC) of less than 1.5 cm without preoperative indications of local or distant metastasis. The primary outcomes assessed were recurrence rates, disease-specific mortality, and quality of life (QoL). Data were collected from prominent databases, including Cochrane Database, Embase, MEDLINE, and Scopus, from inception to June 3rd, 2020. The CLARITY tool was utilized to evaluate bias risk. The analysis involved odds ratios (OR) with 95% confidence intervals (CI) for dichotomous outcomes, as well as mean differences (MD) and standardized mean differences (SMD) for continuous outcomes. The study is registered on PROSPERO under the identifier CRD42021235657. RESULTS: The study incorporated 13 retrospective cohort studies involving 4034 patients. Surgical thyroid resection (TSR), active surveillance (AS), and minimally invasive techniques like radiofrequency ablation (RFA), microwave ablation (MWA), and laser ablation (LA) were performed in varying proportions of cases. The analysis indicated that specific disease mortality rates were comparable among AS, MWA, and TSR groups. The risk of recurrence, evaluated over different follow-up periods, showed no significant differences when comparing AS, RFA, MWA, or LA against TSR. Patients undergoing AS demonstrated better physical health-related quality of life (QoL) than those undergoing TSR. However, no substantial differences were observed in the overall mental health domain of QoL when comparing AS or RFA with TSR. The risk of bias was moderate in nine studies and high in four. CONCLUSION: Low-quality evidence indicates comparable recurrence and disease-specific mortality risks among patients with LPTC who underwent ablation techniques or active surveillance (AS) compared to surgery. Nevertheless, individuals who opted for AS exhibited enhanced physical quality of life (QoL). Subsequent investigations are warranted to validate these findings.

Comparison of voltage maps using OCTARAY catheter and PENTARAY catheter.

BACKGROUND: Recently, a new OCTARAY® mapping catheter was commercially launched. The catheter is designed to enable high-density mapping and precise signal recording via 48 small electrodes arranged on eight radiating splines. The purpose of this study was to compare bipolar voltage and low-voltage-area size, and mapping efficacy between the OCTARAY catheter and the PENTARAY® catheter METHODS: Twelve consecutive patients who underwent initial and second ablations for persistent atrial fibrillation within 2 years were considered for enrollment. Voltage mapping was performed twice, first during the initial ablation using the PENTARY catheter and second during the second ablation using the OCTARAY Long 3-3-3-3-3 (L3) catheter. RESULTS: Mean voltage with the OCTARAY-L3 catheter (1.64 ± 0.57 mV) was 32.3% greater than that with the PENTARAY catheter (1.24 ± 0.46 mV, p < .0001) in total left atrium. Low-voltage-area (<0.50 mV) size with the OCTARAY-L3 catheter was smaller than that with the PENTARAY catheter (6.9 ± 9.7 vs. 11.4 ± 13.0 cm2 , p < .0001). The OCTARAY-L3 catheter demonstrated greater efficacy than the PENTARAY catheter in terms of shorter mapping time (606 ± 99 vs. 782 ± 211 s, p = .008) and more mapping points (3,026 ± 838 vs. 781 ± 342 points, p < .0001). CONCLUSION: The OCTARAY catheter demonstrated higher voltage recordings, narrower low-voltage areas, and a more efficacious mapping procedure than the PENTARAY catheter.

Reliable focal and rotational activations in CARTOFINDER mapping using the OctaRay catheter.

INTRODUCTION: The aim of the current study was to elucidated the reliable atrial fibrillation (AF) drivers identified by CARTOFINDER using OctaRay catheter. METHODS AND RESULTS: The reliability of focal and rotational activations identified by CARTOFINDER using OctaRay catheter was assessed by the sequential recordings in each site of both atrium before and after pulmonary vein isolation (PVI) in 10 persistent AF patients. The outcome measures were the reproducibility rate during the sequential recordings and the stability rate between pre- and post-PVI as reliable focal and rotational activations. The study results were compared with those under use of PentaRay catheter (N = 18). Total 68928 points of 360 sites in OctaRay group and 24 177 points of 311 sites in PentaRay were assessed. More focal activation sites were identified in OctaRay group than PentaRay group (7.9% vs. 5.7%, p < .001), although the reproducibility rate and the stability rate were significantly lower in OctaRay group (45.3% vs. 58.9%, p < .001; 11.2% vs. 28.4%, p < .001). Meanwhile, the prevalence of reproducible focal activation sites among overall points was comparable (3.6% vs. 3.3%, p = .08). Regarding rotational activation, more rotational activation sites were identified in OctaRay group (5.1% vs. 0.2%, p < .001), and the reproducibility rate and the stability rate were significantly higher in OctaRay group (45.2% and 12.5% vs. 0.0%, p < .001). Both reliable focal and rotational activation sites were characterized by significantly shorter AF-cycle length (CL) and higher repetition of focal and rotational activations during the recordings compared with the sites of non or unreliable focal and rotational activations. CONCLUSION: In CARTOFINDER, OctaRay catheter could identify reliable focal activation with high resolution and reliable rotational activation compared with PentaRay catheter. The repetitive focal and rotational activations with short AF-CL could be the potential target during ablation.

Thermal ablation of hepatocellular carcinoma.

Percutaneous treatment of hepatocellular carcinoma (HCC) by means of thermal ablation (TA) has been introduced in clinical guidelines as a potentially curative treatment for the early stages of the disease since the early 2000s. Due to its safety profile and cost-effectiveness, TA can be offered as a first-line treatment for patients with HCC smaller than 3 cm. Thermal ablative techniques are in fact widely available at many centres worldwide and include radiofrequency (RF) and microwave (MW) ablation, with the latter increasingly applied in clinical practice in the last decade. Pre-clinical studies highlighted, as potential advantages of MW-based ablation, the ability to achieve higher temperatures (>100°C) and larger ablation zones in shorter times, with less susceptibility to blood flow-induced heat sink effects. Despite these advantages, there is no evidence of superior overall survival in patients treated with MW as compared to those treated with RF ablation. Local control has been proven to be superior to MW ablation with a similar complication rate. It is expected that further improvement of TA results in the treatment of HCC will result from the refinement of guidance and monitoring tools and the careful assessment of ablation margins. Thermal ablative treatments may also be performed on nodules larger than 3 cm by applying multiple devices or combining percutaneous and intra-arterial approaches. The role of novel immunotherapy regimens in combination with ablation is also currently under evaluation in clinical trials, with several potential benefits. In this review, indications, technical principles, results, and future prospects of TA for the treatment of HCC will be examined.

[Ultrasound-guided ablation techniques for thyroid lesions]. / Ultraschallgeführte lokalablative Verfahren zur Behandlung von Schilddrüsenläsionen.

Ultrasound-guided ablation techniques have been increasingly introduced into routine treatment of thyroid lesions as a complement to existing surgical therapies and radioiodine treatment. In cystic or predominantly cystic lesions instillation therapy (ethanol/polidocanol ablation) has yielded good results. Novel thermal ablation techniques, including radiofrequency ablation (RFA), microwave ablation (MWA), laser ablation (LA) and high intensity focused ultrasound (HIFU), induce irreversible cellular effects by locally applying temperatures ≥ 60 °C to the targeted thyroid region. Lesions causing local symptoms or focal hyperfunctionality can thus be selectively treated under continuous sonographic monitoring. While a considerable body of evidence supports the efficacy and safety of various local ablative techniques, future challenges lie in initiating comparative prospective trials and in standardizing clinical practice, training and continuous quality assessment on a regional and superregional level. In the future, it shall be indicated to include local ablative techniques - so far not known to all patients in Germany - into the informed decision-making process as a suitable alternative or supplement to existing therapies.

Reversible Pulsed Electrical Fields as an In Vivo Tool to Study Cardiac Electrophysiology: The Advent of Pulsed Field Mapping.

BACKGROUND: During electrophysiological mapping of tachycardias, putative target sites are often only truly confirmed to be vital after observing the effect of ablation. This lack of mapping specificity potentiates inadvertent ablation of innocent cardiac tissue not relevant to the arrhythmia. But if myocardial excitability could be transiently suppressed at critical regions, their suitability as targets could be conclusively determined before delivering tissue-destructive ablation lesions. We studied whether reversible pulsed electric fields (PFREV) could transiently suppress electrical conduction, thereby providing a means to dissect tachycardia circuits in vivo. METHODS: PFREV energy was delivered from a 9-mm lattice-tip catheter to the atria of 12 swine and 9 patients, followed by serial electrogram assessments. The effects on electrical conduction were explored in 5 additional animals by applying PFREV to the atrioventricular node: 17 low-dose (PFREV-LOW) and 10 high-dose (PFREV-HIGH) applications. Finally, in 3 patients manifesting spontaneous tachycardias, PFREV was applied at putative critical sites. RESULTS: In animals, the immediate post-PFREV electrogram amplitudes diminished by 74%, followed by 78% recovery by 5 minutes. Similarly, in patients, a 69.9% amplitude reduction was followed by 84% recovery by 3 minutes. Histology revealed only minimal to no focal, superficial fibrosis. PFREV-LOW at the atrioventricular node resulted in transient PR prolongation and transient AV block in 59% and 6%, while PFREV-HIGH caused transient PR prolongation and transient AV block in 30% and 50%, respectively. The 3 tachycardia patients had atypical atrial flutters (n=2) and atrioventricular nodal reentrant tachycardia. PFREV at putative critical sites reproducibly terminated the tachycardias; ablation rendered the tachycardias noninducible and without recurrence during 1-year follow-up. CONCLUSIONS: Reversible electroporation pulses can be applied to myocardial tissue to transiently block electrical conduction. This technique of pulsed field mapping may represent a novel electrophysiological tool to help identify the critical isthmus of tachycardia circuits.

Chinese expert consensus on the construction of the fluoroless cardiac electrophysiology laboratory and related techniques.

Transcatheter radiofrequency ablation has been widely introduced for the treatment of tachyarrhythmias. The demand for catheter ablation continues to grow rapidly as the level of recommendation for catheter ablation. Traditional catheter ablation is performed under the guidance of X-rays. X-rays can help display the heart contour and catheter position, but the radiobiological effects caused by ionizing radiation and the occupational injuries worn caused by medical staff wearing heavy protective equipment cannot be ignored. Three-dimensional mapping system and intracardiac echocardiography can provide detailed anatomical and electrical information during cardiac electrophysiological study and ablation procedure, and can also greatly reduce or avoid the use of X-rays. In recent years, fluoroless catheter ablation technique has been well demonstrated for most arrhythmic diseases. Several centers have reported performing procedures in a purposefully designed fluoroless electrophysiology catheterization laboratory (EP Lab) without fixed digital subtraction angiography equipment. In view of the lack of relevant standardized configurations and operating procedures, this expert task force has written this consensus statement in combination with relevant research and experience from China and abroad, with the aim of providing guidance for hospitals (institutions) and physicians intending to build a fluoroless cardiac EP Lab, implement relevant technologies, promote the standardized construction of the fluoroless cardiac EP Lab.

Baseline left atrial low-voltage area predicts recurrence after pulmonary vein isolation: WAVE-MAP AF results.

AIMS: Electro-anatomical mapping may be critical to identify atrial fibrillation (AF) subjects who require substrate modification beyond pulmonary vein isolation (PVI). The objective was to determine correlations between pre-ablation mapping characteristics and 12-month outcomes after a single PVI-only catheter ablation of AF. METHODS AND RESULTS: This study enrolled paroxysmal AF (PAF), early persistent AF (PsAF; 7 days-3 months), and non-early PsAF (>3-12 months) subjects undergoing de novo PVI-only radiofrequency catheter ablation. Sinus rhythm (SR) and AF voltage maps were created with the Advisor HD Grid™ Mapping Catheter, Sensor Enabled™ for each subject, and the presence of low-voltage area (LVA) (low-voltage cutoffs: 0.1-1.5 mV) was investigated. Follow-up visits were at 3, 6, and 12 months, with a 24-h Holter monitor at 12 months. A Cox proportional hazards model identified associations between mapping data and 12-month recurrence after a single PVI procedure. The study enrolled 300 subjects (113 PAF, 86 early PsAF, and 101 non-early PsAF) at 18 centres. At 12 months, 75.5% of subjects were free from AF/atrial flutter (AFL)/atrial tachycardia (AT) recurrence. Univariate analysis found that arrhythmia recurrence did not correlate with AF diagnosis, but LVA was significantly correlated. Low-voltage area (<0.5 mV) >28% of the left atrium in SR [hazard ratio (HR): 4.82, 95% confidence interval (CI): 2.08-11.18; P = 0.0003] and >72% in AF (HR: 5.66, 95% CI: 2.34-13.69; P = 0.0001) was associated with a higher risk of AF/AFL/AT recurrence at 12 months. CONCLUSION: Larger extension of LVA was associated with an increased risk of arrhythmia recurrence. These subjects may benefit from substrate modification beyond PVI.

False Tendons in the Left Ventricle: Implications for Successful Ablation of Left Posterior Fascicular Tachycardias.

BACKGROUND: The anatomical substrate for left posterior fascicular ventricular tachycardia (LPF-VT) is still unclear. OBJECTIVES: The purpose of this study is to describe the endocavitary substrate of the re-entrant loop of LPF-VT. METHODS: A total of 26 consecutive patients with LPF-VT underwent an electrophysiology study and radiofrequency ablation. RESULTS: Intracardiac echocardiography imaging observed a 100% prevalence of false tendons (FTs) at the left posterior septal region in all patients, and 3 different types of FTs could be classified according to their location. In 22 patients, a P1 potential could be recorded via the multielectrode catheter from a FT. In 4 patients without a recorded P1 during LPF-VT, the earliest P2 potentials were recorded from a FT in 3 patients, and from a muscular connection between 2 posteromedial papillary muscles in 1 patient. Catheter ablation focused on the FTs with P1 or earliest P2 (in patients without P1) was successful in all 26 patients. After 19 ± 8.5 months of follow-up, no patients had recurrence of LPF-VT. CONCLUSIONS: FTs provide an electroanatomical substrate for LPF-VT and a "culprit FT" may be identified as the critical structure bridging the macro-re-entrant loop. Targeting the "culprit FT" is a novel anatomical ablation strategy that results in long-term arrhythmia-free survival.

Impact of Interatrial Epicardial Connections on the Dominant Frequency of Atrial Fibrillation.

BACKGROUND: An epicardial connection (EC) between the right-sided pulmonary venous (RtPV) carina and right atrium (RA) may preclude PV isolation, but its electrophysiological role during atrial fibrillation (AF) remains unknown.Methods and Results: This prospective observational study included 98 consecutive patients undergoing catheter ablation for AF, subdivided into the EC group (n=17) and non-EC group (n=80) based on observation of RA posterior wall breakthrough during RtPV pacing. Mean left atrial (LA) dominant frequency (mean DFLA) was defined as the averaged DFs at the right and left PVs and LA appendage. The regional DF was higher in the EC group vs. the non-EC group except at the left PV antrum. The DF at the RA appendage (RAA) and mean DFLAwere equivocal (6.5±0.7 vs. 6.6±0.7 Hz) in the EC group, but the mean DFLAwas significantly higher than that at the RAA (5.8±0.6 vs. 6.1±0.5 Hz, P=0.001) in the non-EC group, suggesting an LA-to-RA DF gradient. A significant correlation of DF between the RtPV antrum and RAA was observed in the EC group (P<0.001, r=0.84) but not in the non-EC group. CONCLUSIONS: An electrophysiological link via interatrial ECs might attenuate the hierarchical nature of activation frequencies of AF, leading to advanced electrical remodeling of the atria.

Effectiveness of a Mindfulness Meditation App Based on an Electroencephalography-Based Brain-Computer Interface in Radiofrequency Catheter Ablation for Patients With Atrial Fibrillation: Pilot Randomized Controlled Trial.

BACKGROUND: Radiofrequency catheter ablation (RFCA) for patients with atrial fibrillation (AF) can generate considerable physical and psychological discomfort under conscious sedation. App-based mindfulness meditation combined with an electroencephalography (EEG)-based brain-computer interface (BCI) shows promise as effective and accessible adjuncts in medical practice. OBJECTIVE: This study aimed to investigate the effectiveness of a BCI-based mindfulness meditation app in improving the experience of patients with AF during RFCA. METHODS: This single-center pilot randomized controlled trial involved 84 eligible patients with AF scheduled for RFCA, who were randomized 1:1 to the intervention and control groups. Both groups received a standardized RFCA procedure and a conscious sedative regimen. Patients in the control group were administered conventional care, while those in the intervention group received BCI-based app-delivered mindfulness meditation from a research nurse. The primary outcomes were the changes in the numeric rating scale, State Anxiety Inventory, and Brief Fatigue Inventory scores. Secondary outcomes were the differences in hemodynamic parameters (heart rate, blood pressure, and peripheral oxygen saturation), adverse events, patient-reported pain, and the doses of sedative drugs used in ablation. RESULTS: BCI-based app-delivered mindfulness meditation, compared to conventional care, resulted in a significantly lower mean numeric rating scale (mean 4.6, SD 1.7 [app-based mindfulness meditation] vs mean 5.7, SD 2.1 [conventional care]; P=.008), State Anxiety Inventory (mean 36.7, SD 5.5 vs mean 42.3, SD 7.2; P<.001), and Brief Fatigue Inventory (mean 3.4, SD 2.3 vs mean 4.7, SD 2.2; P=.01) scores. No significant differences were observed in hemodynamic parameters or the amounts of parecoxib and dexmedetomidine used in RFCA between the 2 groups. The intervention group exhibited a significant decrease in fentanyl use compared to the control group, with a mean dose of 3.96 (SD 1.37) mcg/kg versus 4.85 (SD 1.25) mcg/kg in the control group (P=.003).The incidence of adverse events was lower in the intervention group (5/40) than in the control group (10/40), though this difference was not significant (P=.15). CONCLUSIONS: BCI-based app-delivered mindfulness meditation effectively relieved physical and psychological discomfort and may reduce the doses of sedative medication used in RFCA for patients with AF. TRIAL REGISTRATION: ClinicalTrials.gov NCT05306015; https://clinicaltrials.gov/ct2/show/NCT05306015.

Impact of the introduction of minimally invasive treatments of the thyroid (MITT) for benign thyroid nodules in an Italian hospital: a cost-minimization analysis.

BACKGROUND: Prevalence of thyroid nodules is high in the adult population, approaching 60% in women and older people. Most thyroid nodules are benign and asymptomatic. However, a not negligible part of them causes compressive symptoms and/or cosmetic concerns and need to be treated. In the last two decades, minimally-invasive treatments of the thyroid (MITT) have been proposed in routine clinical practice as a reliable cost-effective alternative to surgery in patients with symptomatic benign thyroid nodules (SBTNs). AIM OF THE STUDY: To perform a cost-minimization analysis comparing direct, indirect and intangible costs of radiofrequency (RFA) and laser thermal ablation (LTA) with traditional surgery in patients with SBTNs. METHODS: Data of patients treated by MITT for SBTNs from October 1st 2019 to September 30th 2022 in a single Italian tertiary Center were analyzed. Costs were compared to those of traditional surgery reported in the 2022 Associazione Medici Endocrinologi Guidelines on the Management of SBTNs. RESULTS: In the study lapse, 157 MITT of SBTNs were performed in 148 patients, 114 females and 34 males (mean age: 59 yrs; median age: 57 yrs). Before MITT, the mean thyroid nodule volume was 19 ml; 1 year after MITT, volume reduction rate >50% and symptom relief were achieved in 89% and 93% of patients, respectively. No major complications occurred. Adding up pre-operative, operative and post-operative costs, total direct costs per single procedure are the following: 1361.43 € for LTA when using one optic fiber; 1761.43 € for LTA when using two optic fibers; 1968.53 € for RFA; 3338.39 € for hemithyroidectomy plus isthmectomy; 4034.99 € for total thyroidectomy. Surgery was impactful on direct-i.e., preoperative, operative and postoperative-costs, due to longer operating room occupation time and hospital stay. Overall, a total saving for the Italian National Health Service of 285,377.15 € has been obtained treating the 148 patients by MITT instead of surgery. Likewise, MITT was advantageous also for indirect costs-i.e., those related to "loss of productivity" caused by time off work due to hospital stay and recovery time-, for both the self-employed workers and the Government, the latter saving 53,838.50 € overall. Finally, intangible costs, related to patients' quality of life-e.g., residual surgical scar, stress related to general anesthesia, convalescence, and life-long intake of L-Thyroxine replacement therapy-were all in favor of MITT. CONCLUSIONS: This real-life cost-minimization analysis demonstrates that LTA and RFA are safe and cost-effective procedures for the treatment of SBTNs. In our 3 years experience, adding the savings of 285,377.15 € for direct costs to those of 53.838,50 € for indirect costs, in total 339,215.65 € were saved. The saving concern patients, the National Health System and the Government.

In Atrial Fibrillation, Omnipolar Voltage Maps More Accurately Delineate Scar Than Bipolar Voltage Maps.

BACKGROUND: Optimal method for voltage assessment in AF remains unclear. OBJECTIVES: This study evaluated different methods for assessing atrial voltage and their accuracy in identifying pulmonary vein reconnection sites (PVRSs) in atrial fibrillation (AF). METHODS: Patients with persistent AF undergoing ablation were included. De novo procedures: voltage assessment in AF with omnipolar voltage (OV) and bipolar voltage (BV) methodology and BV assessment in sinus rhythm (SR). Activation vector and fractionation maps were reviewed at voltage discrepancy sites on OV and BV maps in AF. AF voltage maps were compared with SR BV maps. Repeat ablation procedures: OV and BV maps in AF were compared to detect gaps in wide area circumferential ablation (WACA) lines that correlated with PVRS. RESULTS: Forty patients were included: 20 de novo and 20 repeat procedures. De novo procedure: OV vs BV maps in AF; average voltage 0.55 ± 0.18 mV vs 0.38 ± 0.12 mV; P = 0.002, voltage difference of 0.20 ± 0.07 mV; P = 0.003 at coregistered points and proportion of left atrium (LA) area occupied by low-voltage zones (LVZs) was smaller on OV maps (42.4% ± 12.8% OV vs 66.7% ± 12.7% BV; P < 0.001). LVZs identified on BV maps and not on OV maps correlated frequently to wavefront collision and fractionation sites (94.7%). OV AF maps agreed better with BV SR maps (voltage difference at coregistered points 0.09 ± 0.03 mV; P = 0.24) unlike BV AF maps (0.17 ± 0.07 mV, P = 0.002). Repeat ablation procedure: OV was superior in identifying WACA line gaps that correlated with PVRS than BV maps (area under the curve = 0.89, P < 0.001). CONCLUSIONS: OV AF maps improve voltage assessment by overcoming the impact of wavefront collision and fractionation. OV AF maps correlate better with BV maps in SR and more accurately delineate gaps on WACA lines at PVRS.

Impact of anesthetic management on catheter ablation for premature ventricular complexes: insights during the COVID-19 outbreak.

BACKGROUND: The influence of divergent anesthesia types during ablation of premature ventricular complexes (PVCs) is not known. While previously performed under general anesthesia (GA) at our institution, these procedures were exclusively performed under local anesthesia (LA) ± minimal sedation during the COVID-19 outbreak for logistic reasons. METHODS: One hundred and eight consecutive patients (82 GA versus 26 LA) undergoing PVC ablation at our center were evaluated. Intraprocedural PVC burden (over 3 min) pre-ablation was measured twice: (1) at the start (before GA induction) and (2) before catheter insertion (after GA induction). Upon cessation of ablation and after a waiting period of ≥ 15 min, acute ablation success (AAS) was defined as absence of PVCs until the end of the recording period. RESULTS: Intraprocedural PVC burden was not significantly different between LA versus GA group: (1) 17.8 ± 3% vs 12.7 ± 2%, P = 0.17 and (2) 10.0 ± 3% vs 7.4 ± 1%, P = 0.43, respectively. Activation mapping-based ablation was performed significantly more in the LA vs GA group (77% vs 26% of patients, P < 0.001, respectively). AAS was significantly higher in LA vs GA group: 22/26 (85%) vs 41/82 (50%), respectively, P < 0.01. After multivariable analysis, LA was the only independent predictor for AAS (OR 13, 95% CI 1.57-107.4, P = 0.017). CONCLUSION: Ablation of PVC under LA presented significantly higher AAS rate compared to GA. The procedure under GA might be complicated by PVC inhibition (after catheter insertion/during mapping) and PVC disinhibition post-extubation.

Multi-centre, prospective randomized comparison of three different substrate ablation strategies for persistent atrial fibrillation.

AIMS: The optimal strategy for persistent atrial fibrillation (PerAF) is poorly defined. We conducted a multicentre, randomized, prospective trial to compare the outcomes of different ablation strategies for PerAF. METHODS AND RESULTS: We enrolled 450 patients and randomly assigned them in a 1:1:1 ratio to undergo pulmonary vein isolation and subsequently undergo the following three different ablation strategies: anatomical guided ablation (ANAT group, n = 150), electrogram guided ablation (EGM group, n = 150), and extensive electro-anatomical guided ablation (EXT group, n = 150). The primary endpoint was freedom from atrial fibrillation (AF) lasting longer than 30 s at 12 months after a single ablation procedure. After 12 months of follow-up, 72% (108) of patients in the EXT group were free from AF recurrence, as compared with the 64% (96) in the EGM group (P = 0.116), and 54% (81) in the ANAT group (P = 0.002). The EXT group showed less AF/atrial tachycardia recurrence than the EGM group (60% vs. 50%, P = 0.064) and the ANAT group (60% vs. 37.3%, P < 0.001). The EXT group showed the highest rate of AF termination (66.7%), followed by 56.7% in the EGM group, and 20.7% in the ANAT group. The AF termination signified less AF recurrence at 12 months compared to patients without AF termination (30.1% vs. 42.7%, P = 0.008). Safety endpoints did not differ significantly between the three groups (P = 0.924). CONCLUSIONS: Electro-anatomical guided ablation achieved the most favourable outcomes among the three ablation strategies. The AF termination is a reliable ablation endpoint.

Experiments on physical ablation of long bone using microwave ablation; defining optimal settings using ex- and in-vivo experiments.

BACKGROUND: Improved survival of cancer patients leads to more skeletal metastatic lesions that need local therapies for tumor control and pain relief. Not all tumors are radiosensitive and alternative therapies are direly needed. Microwave ablation (MWA) is a technique for minimally invasive local tumor control by physical ablation. In soft tissue local temperature ablation is more common, but studies on bone tissue are limited. To ensure safe and effective treatment, studies on local tumor ablation in bone are needed. METHOD: Microwave ablation was performed on sheep bone, for both in- and ex-vivo settings. Both a slow-cooking MWA protocol (gradually increasing wattage in the first two minutes of ablation) and a fast-cooking protocol (no warm-up period) were used. Heat distribution through the bone during ablation was determined by measuring temperature at 10- and 15mm from the ablation probe (= needle). Ablation size after procedure was measured using nitro-BT staining. RESULTS: In-vivo ablations led to up to six times larger halos than ex-vivo with the same settings. Within both ex- and in-vivo experiments, no differences in halo size or temperature were found for different wattage levels (65W vs 80W). Compared to a fast cooking protocol, a two-minute slow cooking protocol led to increased temperatures and larger halos. Temperatures at 10- and 15mm distance from the needle no longer increased after six minutes. Halo sizes kept increasing over time without an evident plateau. CONCLUSION: Microwave ablation is technically effective for creating cell death in (sheep) long bone. It is recommended to start ablations with a slow-cooking period, gradually increasing the surrounding tissue temperature in two minutes from 40 to 90°C. Ex-vivo results cannot simply be translated to in-vivo.