Ablation Approach Research Articles

Dual‐Active Center AgFeCu Nanocatalyst for Tumor Destruction via Self‐Catalytically Enhanced Mild Photothermal Therapy

AbstractMild photothermal therapy (mPTT) has emerged as a highly promising approach for tumor ablation. However, the heat‐induced overexpression of heat shock proteins (HSPs) limits its efficacy by increasing cellular temperature tolerance. Herein, a self‐catalytically enhanced mild PTT strategy that directly disrupts the structure of HSPs to restore tumor cell sensitivity is proposed. In the proof‐of‐concept study, AgFeCu nanoparticles (AgFeCu NPs) with dual‐active catalytic centers (Fe‐Cu) and near‐infrared photothermal properties are developed. The AgFeCu NPs can efficiently catalyze the conversion of endogenous hydrogen peroxide into hydroxyl radicals in situ, leading to the degradation of HSPs and enhancing the therapeutic effects of mild PTT mediated by their Ag‐based substrates. Furthermore, AgFeCu NPs can also induce oxidative stress by depleting intracellular glutathione and promoting lipid peroxidation, thereby triggering tumor ferroptosis and resulting in significant tumor elimination in a U87MG murine tumor model. This self‐catalytically enhanced strategy maximizes the efficacy of mild PTT while minimizing damage to healthy tissues, which is expected to provide valuable insights for the development of next‐generation photothermal nanoagents for improved tumor therapeutics.

Magnetic resonance detection of advanced atrial cardiomyopathy increases the risk for atypical atrial flutter occurrence following atrial fibrillation ablation.

Recurrence of arrhythmia after catheter ablation of atrial fibrillation (AF) in the form of atypical atrial flutter (AFL) is common among a significant number of patients and often requires redo ablation with limited success rates. Identifying patients at high risk of AFL after AF ablation could aid in patient selection and personalized ablation approach. The study aims to assess the relationship between pre-existing atrial cardiomyopathy and the occurrence of AFL following AF ablation. We analysed a cohort of 1007 consecutive AF patients who underwent catheter ablation and were included in a prospective registry. Patients who did not have baseline cardiac magnetic resonance imaging and late gadolinium enhancement (LGE-CMR) or did not experience any recurrences were excluded. A total of 166 patients were included gathering 56 patients who underwent re-ablation due to AFL recurrences and 110 patients who underwent re-ablation due to AF recurrences (P = 0.11). A multiparametric assessment of atrial cardiomyopathy was based on basal LGE-CMR, including left atrial (LA) volume, LA sphericity, and global and segmental LA fibrosis using semiautomated post-processing software. Out of the initial cohort of 1007 patients, AFL and AF occurred in 56 and 110 patients, respectively. An age higher than 65 [odds ratio (OR) = 5.6, 95% confidence interval (CI): 2.2-14.4], the number of previous ablations (OR = 3.0, 95% CI: 1.2-7.8), and the management of ablation lines in the index procedure (OR = 2.5, 95% CI: 1.0-6.3) were independently associated with AFL occurrence. Furthermore, several characteristics assessed by LGE-CMR were identified as independent predictors of AFL recurrence after the index ablation for AF, such as enhanced LA sphericity (OR = 1.3, 95% CI: 1.1-1.6), LA global fibrosis (OR = 1.03, 95% CI: 1.01-1.07), and increased fibrosis in the lateral wall (OR = 1.03, 95% CI: 1.01-1.04). Advanced atrial cardiomyopathy assessed by LGE-CMR, such as increased LA sphericity, global LA fibrosis, and fibrosis in the lateral wall, is independently associated with arrhythmia recurrence in the form of AFL following AF ablation.

Determinants of acute irreversible electroporation lesion characteristics after pulsed field ablation: the role of voltage, contact, and adipose interference.

Pulsed field ablation (PFA) is a non-thermal ablative approach in which cardiomyocyte death is obtained through irreversible electroporation (IRE). Data correlating the biophysical characteristics of IRE and lesion characteristics are limited. The aim of this study was to assess the effect of different procedural parameters [voltage, number of cycles (NoCs), and contact] on lesion characteristics in a vegetal and animal model for IRE. Two hundred and four Russet potatoes were used. Pulsed field ablation lesions were delivered on 3 cm cored potato specimens using a multi-electrode circular catheter with its dedicated IRE generator. Different voltage (from 300 to 1200 V) and NoC (from 1 to 5×) protocols were used. The impact of 0.5 and 1 mm catheter-to-specimen distances was tested. A swine animal model was then used to validate the results observed in the vegetable model. The association between voltage, the NoCs, distance, and lesion depth was assessed through linear regression. An almost perfect linear association between lesion depth and voltage was observed (R2 = 0.95; P < 0.001). A similarly linear relationship was observed between the NoCs and the lesion depth (R2 = 0.73; P < 0.001). Compared with controls at full contact, a significant dampening on lesion depth was observed at 0.5 mm distance (1000 V 2×: 2.11 ± 0.12 vs. 0.36 ± 0.04, P < 0.001; 2.63 ± 0.10 vs. 0.43 ± 0.08, P < 0.001). No lesions were observed at 1.0 mm distance. In a vegetal and animal model for IRE assessment, PFA lesion characteristics were found to be strongly dependent on voltage settings and the NoCs, with a quasi-linear relationship. The lack of catheter contact was associated with a dampening in lesion depth.

Segmental Yttrium-90 Radioembolization Using Glass Microspheres Greater than 400 Gray for the Treatment of Intrahepatic Cholangiocarcinoma: A Preliminary Experience

Radiation segmentectomy with a dose of >190 Gy using yttrium-90 (90Y) glass microspheres for intrahepatic cholangiocarcinoma (iCCA) has been shown to be safe and effective. The present study further increased the dose to >400 Gy for treatment of iCCA as complete pathologic necrosis has been shown in hepatocellular carcinoma using this ablative approach. A total of 10 patients with 13 tumors (median size, 5.3 cm; range, 1.5–13.6 cm) at a single institution underwent >400-Gy segmental radioembolization. Objective response was achieved in all tumors (13 of 13, 100%). One patient developed a Grade 3 or greater major adverse event (stroke and hepatic decompensation). One patient was bridged to transplant (>95% pathologic necrosis), whereas another underwent resection (>99% necrosis). Contralateral hypertrophy was observed in 6 out of 6 patients treated with modified lobectomy dosing, with a functional liver reserve increase from a median of 31.5% to 57.1%. The present report suggests that segmental transarterial radioembolization with >400 Gy is feasible in terms of safety and effectiveness for treating iCCA.

Short and Long-Term Outcomes of Lesion Index-Guided High-Power Short-Duration Approach for Atrial Fibrillation Ablation.

High-power short-duration (HPSD) ablation is an increasingly used ablation strategy for pulmonary vein isolation (PVI) procedures, but Lesion Index (LSI)-guided HPSD radiofrequency (RF) applications have not been described in this clinical setting. We evaluated the procedural efficiency and safety of an LSI-guided HPSD strategy for atrial fibrillation (AF) ablation. Paroxysmal and persistent AF patients scheduled for AF ablation were prospectively enrolled and divided into two groups, according to the ablation power used (≥45 W for the LSI-HP Group and ≤40 W for the LSI-LP group). All patients underwent only PVI LSI-guided ablation (5.5 to 6 anteriorly; 5 to 5.5 superiorly, 4.5 to 5 posteriorly) with a point-by-point strategy and an inter-lesion distance <6 mm. Forty-six patients with AF (25 in the LSI-HP Group vs 21 in the LSI-LP Group)-59% paroxysmal, 78% male, with low-intermediate CHA2DS2-Vasc scores (2 [1-3]), a preserved ejection fraction (65 ± 6%) and a mean left atrial index volume of 39 ± 13 mL/m2 were prospectively enrolled. Baseline clinical characteristics were comparable between groups. PVI was successful in all patients. The RF time (29 (23-37) vs. 49 (41-53) min, p < 0.001), total procedure time (131 (126-145) vs. 155 (139-203) min, p = 0.007) and fluoroscopy time (12 (10-18) vs. 21 (16-26) min, p = 0.001) were significantly lower in the LSI-HP Group. No complications or steam pops were seen in either group. LSI-HP AF ablation significantly improved procedural efficiency-reducing ablation time, total procedural duration, and fluoroscopy use, while maintaining a comparable safety profile to lower-power procedures.

Septal Substrate Ablation Guided by Delayed Transmural Conduction Times: A Novel Ablation Approach to Target Intramural Substrates

BackgroundIntraprocedural identification of intramural septal substrate for ventricular tachycardia (ISS-VT) in nonischemic cardiomyopathy (NICM) is challenging. Delayed (>40 ms) transmural conduction time (DCT) with right ventricular basal septal pacing has been previously shown to identify ISS-VT. ObjectivesThis study sought to determine whether substrate catheter ablation incorporating areas of DCT may improve acute and long-term outcomes. MethodsWe included patients with NICM and ISS-VT referred for catheter ablation between 2016 and 2020. ISS-VT was defined by the following: 1) confluent septal areas of low unipolar voltage (<8.3 mV) in the presence of normal or minimal bipolar abnormalities; and 2) presence of abnormal electrograms in the septum. Substrate ablation was guided by the following: 1) activation and/or entrainment mapping for tolerated VT and pace mapping with ablation of abnormal septal electrograms for unmappable VTs (n = 57, Group 1); and 2) empirically extended to target areas of DCT during right ventricular basal septal pacing regardless of their participation in inducible VT(s) but sparing the conduction system when possible (n = 24, Group 2). ResultsThere were no significant baseline differences between Groups 1 and 2. Noninducibility of any VT programmed stimulation at the end of ablation was higher in Group 2 compared with Group 1 (80% vs 53%; P = 0.03). At 12-month follow-up, single-procedure VT-free survival was significantly higher (79% vs 46%; P = 0.006) and the time to VT recurrence was longer (mean 10 ± 3 months vs 7 ± 4 months; P = 0.02) in Group 2 compared with Group 1. ConclusionsIn patients with NICM and ISS-VT, a substrate ablation strategy that incorporates areas of DCT appears to improve freedom from recurrent VT.

Practical guidance to reduce radiation exposure in electrophysiology applying ultra low-dose protocols: a European Heart Rhythm Association review.

Interventional electrophysiology offers a great variety of treatment options to patients suffering from symptomatic cardiac arrhythmia. Catheter ablation of supraventricular and ventricular tachycardia has globally evolved a cornerstone in modern arrhythmia management. Complex interventional electrophysiological procedures engaging multiple ablation tools have been developed over the past decades. Fluoroscopy enabled interventional electrophysiologist throughout the years to gain profound knowledge on intracardiac anatomy and catheter movement inside the cardiac cavities and hence develop specific ablation approaches. However, the application of X-ray technologies imposes serious health risks to patients and operators. To reduce the use of fluoroscopy during interventional electrophysiological procedures to the possibly lowest degree and to establish an optimal protection of patients and operators in cases of fluoroscopy is the main goal of modern radiation management. The present manuscript gives an overview of possible strategies of fluoroscopy reduction and specific radiation protection strategies.

Clinical outcomes and cost of open, laparoscopic, and percutaneous ablation for hepatocellular carcinoma.

Open (OA), laparoscopic (LA), and percutaneous (PA) ablation are all ablation approaches for hepatocellular carcinoma (HCC) utilized in the United States today. However, it remains unclear today which approach is (A) most effective, (B) cost-efficient, and (C) nationally practiced. In-hospital mortality and cost were collected from the National Inpatient Sample (NIS) database for patients undergoing liver ablation from 2011 to 2018. Secondary outcomes included length of stay, disposition, and perioperative composite complications. We used inverse probability of treatment weighting (IPTW) to adjust for differences in patient and hospital baseline characteristics. One thousand and one hundred and twenty-five LA, 1221 OA, and 1068 PA liver ablations were analyzed. After IPTW, in-hospital mortality risk was significantly lower in PA versus OA cohorts (0.57% vs. 2.90%, p < 0.001) and reduced among PA patients, yet not significantly different from the LA cohort (0.57% vs. 1.64%, p = 0.056). The median length of hospital stay was significantly lower in the PA and LA group compared to OA (2 days vs. 6 days, p < 0.001). The median hospitalization costs were significantly lower for PA ($44,884 vs. $90,187, p < 0.001) and LA ($61,445 vs. $90,187, p < 0.001) compared to OA. Moreover, we found significant regional differences regarding the use of each ablation approach, with the Midwest having the lowest rates of PA and LA. Among patients hospitalized after ablation for HCC, PA leads to the lowest hospital cost. Both PA and LA result in lower peri-operative morbidity and mortality relative to OA. Despite these reported advantages, there are significant regional differences with respect to ablation availability suggesting the need to promote the standardization of best practices.

Endometrium Ablation using a Foley catheter with a cost-effective technique in a hospital environment.

Objective: To evaluate the effectiveness of employing Foley’s catheter and modified thermal balloon ablation to treat heavy menstrual bleeding (HMB). Study Design: Prospective Interventional Randomized Control study. Setting: Departments of Gynecological of Three Semi Government Hospitals of the City. Period: January 2021 to September 2022. Material &amp; Methods: In the study, 12 patients between the ages of 42 and 50 who complained of menorrhagia and who had not responded to treatment for at least 6 months were recruited. Pre-ablation endometrial curettage was performed on each patient. A 30-50 ml latex covered Foley’s Catheter was evaluated after being introduced into uterine cavity, inflated as much as the cavity would allow under moderate pressure, and changed every two minutes with fresh boiling saline for eight minutes. Following that, hysteroscopic examination and a 6-month follow-up were performed to look for endometrial scarring. Results: Significantly shorter hospital stays, shorter recovery times following surgery, and quicker return to normal daily and sexual activities. Regarding problems, menstrual alterations, amenorrhea rate, and failure rate during the course of follow-up, there was no discernible difference between patients. This method has a success rate of almost 88%. Conclusion: In situations with limited resources, improved thermal balloon ablation with a Foley’s catheter can be a potential treatment for HMB. It is a more affordable option that the preliminary endometrial ablation approaches.

The iceberg technique: an innovative approach for radiofrequency ablation of diving thyroid nodules.

Diving thyroid nodules are a limitation of radiofrequency ablation because the mediastinal component cannot be adequately identified by ultrasound (US). We aim to describe a new technique, the iceberg technique, to overcome this issue and explain our three-year experience of using this novel method. The iceberg technique consists of a two-stage treatment. First, the ablation of the cervical portion of the nodules (easily visualized during the initial US exam) using trans-isthmic access is performed using the moving-shot technique. After three to six months, there is a volumetric reduction of the treated portion, leading to retraction of the thyroid parenchyma. This brings the mediastinal component to the cervical region, thereby enabling a perfect visualization by US. Then, the second stage of treatment is carried out with complete nodule ablation, and the region that was treated first is looked at a second time. From April 2018 to April 2021, nine patients with nine benign nodules were submitted for the iceberg technique. No complications occurred during the entire follow-up period. The patients displayed normal hormonal levels after the procedures, and there was a significant volume reduction of the nodules until three months post-ablation. The iceberg technique is an effective and safe option for the radiofrequency treatment of diving goiters.

A macrophage subpopulation promotes airineme-mediated intercellular communication in a matrix metalloproteinase-9 dependent manner

Tissue-resident macrophages are heterogeneous and perform location-dependent functions. Skin resident macrophages play intriguing roles in long-distance intercellular signaling by mediating cellular protrusions called airinemes in zebrafish. These macrophages relay signaling molecules containing airineme vesicles between pigment cells, and their absence disrupts airineme-mediated signaling and pigment pattern formation. It is unknown if the same macrophages control both these signaling and typical immune functions or if a separate subpopulation functions in intercellular communication. With high-resolution imaging and genetic ablation approaches, we identify a macrophage subpopulation responsible for airineme-mediated signaling. These seem to be distinct from conventional skin-resident macrophages by their ameboid morphology and faster or expansive migratory behaviors. They resemble ectoderm-derived macrophages termed metaphocytes. Metaphocyte ablation markedly decreases airineme extension and signaling. In addition, these ameboid/metaphocytes require matrix metalloproteinase-9 for their migration and airineme-mediated signaling. These results reveal a macrophage subpopulation with specialized functions in airineme-mediated signaling, which may play roles in other aspects of intercellular communication.

Adaptive Microwave Ablation System for Localized Tumor Treatment

Though microwave ablation (MWA) technology has shown obvious advantages, it has the problem that the ablation zone is not sufficiently localized. As a result, normal tissue might be inevitably damaged during the ablation process. To solve this problem, the comprehensive MWA theory is first analyzed in this article, and then, a frequency-adaptive ablation approach is proposed and verified by simulations. Accordingly, a frequency-adaptive MWA system for optimizing the ablation zone is developed. As the tissue’s electromagnetic properties change with the increase in temperature during the ablation, the proposed system is designed to monitor the working performance of the antenna in real time and to automatically select the optimum working frequency, simultaneously. The ablation-controlling system is designed as an integrated controller so that the overall size and fabrication cost are obviously reduced. Preliminary validation experiments are performed on the system, which shows that the proposed system is capable of delivering stable power output from 0.5 to 3 GHz and creating a highly localized ablation zone. The proposed MWA system is expected to be a dedicated device for the treatment of tumors.

High-power radiofrequency ablation for ventricular tachycardia in patients with structural heart disease: one-year follow-up data from the multicenter prospective registry

Background: The outcomes of ventricular tachycardia (VT) ablation in patients with structural heart disease (SHD) are not ideal. High-power radiofrequency ablation (RFA) may have a long-term beneficial effect in this patient cohort.Objective: To evaluate the safety, early and long-term efficacy of high-power RFA for VT and concomitant SHD in a multicenter prospective registry.Methods: Our study included a total of 63 patients (66,7% of them were men; median age was 61.0 [51.0-66.5] years) with ischemic heart disease and drug-resistant VT who were scheduled for RFA (50 W). Non-fluoroscopic 3D mapping systems were used for bipolar and activation mapping with standard settings. The safety end point included perioperative complications, such as death, hemopericardium, stroke, myocardial infarction, electrical storm, and vascular complications. The efficacy end points included VT non-inducibility at the end of ablation and freedom from VT at 12 months of the follow-up. The secondary end points were changes in implantable cardioverter-defibrillator (ICD) therapy, sonographic findings, and number of hospital admissions.Results: All patients underwent VT ablation under general sedation. One clinical VT was induced in 96.8% of the patients before ablation. After ablation no clinical VTs were induced (P &lt; .0001 vs baseline). No perioperative complications were observed. Freedom from VT without antiarrhythmic drugs was 82.6% at 12 months of the follow-up. The number of ICD therapies significantly decreased at 12 months of the follow-up compared with baseline (3.2% vs 31.7%, respectively; P = .0001). The left ventricular ejection fraction increased from 48.7% ± 14.7% at baseline to 50.3% ± 11.9% at 12 months of the follow-up (P = .038). There was a statistically significant decrease in hospital admission rate before and after ablation (from 2 [range: 0-12] to 0 [range: 0-3], P &lt; .0001).Conclusion: High-power RFA for VT in patients with ischemia demonstrated its safety and high perioperative and long-term efficacy, which were linked to clinical improvement. Further randomized studies will help introduce this VT ablation approach into routine clinical practice. Received 5 September 2022. Revised 16 February 2023. Accepted 31 May 2023. Funding: The study did not have sponsorship. Conflict of interest: The authors declare no conflict of interest. Contribution of the authorsConception and study design: S.V. Korolev, A.Sh. Revishvili, A.B. Romanov Data collection and analysis: S.V. Korolev, E.A. Artyukhina, V.V. Shabanov, O.V. Sapelnikov, A.V. Tsyganov, A.Sh. Revishvili, A.B. RomanovStatistical analysis: S.V. Korolev Drafting the article: S.V. Korolev Critical revision of the article: A.B. Romanov, A.Sh. Revishvili Final approval of the version to be published: S.V. Korolev, E.A. Artyukhina, V.V. Shabanov, O.V. Sapelnikov, A.V. Tsyganov, A.Sh. Revishvili, A.B. Romanov

Pulsed-Field Ablation on Mitral Isthmus in Persistent Atrial Fibrillation: Preliminary Data on Efficacy and Safety

BackgroundPulsed-field ablation (PFA) is a new and promising modality of ablation that has been shown to specifically ablate cardiac tissue while sparing other anatomic structures, thus avoiding thermal ablation–related complications. Recent studies have certified safety and efficacy of PFA for pulmonary vein isolation (PVI) in the setting of paroxysmal atrial fibrillation (AF). However, there are very limited data assessing the feasibility and safety of PFA ablation of different substrates within the left atrium in the setting of persistent AF. ObjectivesThe purpose of this study was to evaluate the feasibility and safety of mitral isthmus (MI) ablation in addition to PVI and posterior wall (PW) ablation with PFA in patients with persistent AF. MethodsWe prospectively included all consecutive patients with persistent AF who underwent a first ablation procedure with PFA. We performed in all these patients a substrate ablation strategy comprising PVI, PW, and MI ablation with the use of PFA only. The primary feasibility endpoint was obtaining a persistent MI block at the end of the procedure. The safety endpoint was a composite of major safety events. ResultsFrom November 2021 to September 2022, we included 45 patients. Complete MI block was achieved in all 45 (100%). Three patients presented with complications, among them 2 cases (4.4%) of reversible and nonfatal coronary spasm. During a mean follow-up time of 107.8 ± 59.5 days, a 20% recurrence rate was observed. ConclusionsPFA is a feasible and safe ablation approach for mitral isthmus ablation in addition to PVI in patients with persistent AF.

Neural gut-to-brain communication for postprandial control of satiation and glucose metabolism.

The brain is tuned to integrate food-derived signals from the gut, allowing it to accurately adjust behavioral and physiological responses in accordance with nutrient availability. A key element of gut-to-brain communication is the relay of neural cues via peripheral sensory neurons (PSN) which harbor functionally specialized peripheral endings innervating the muscular and mucosal layers of gastrointestinal (GI) tract organs. In this review, we detail the properties of GI tract innervating PSN and describe their roles in regulating satiation and glucose metabolism in response to food consumption. We discuss the complex anatomical organization of vagal and spinal PSN subtypes, their peripheral and central projection patterns, and describe the limitations of unselective lesion and ablation approaches to investigate them. We then highlight the recent identification of molecular markers that allow selective targeting of PSN subtypes that innervate GI tract organs. This has facilitated accurately determining their projections, monitoring their responses to gut stimuli, and manipulating their activity. We contend that these recent developments have significantly improved our understanding of PSN-mediated gut-to-brain communication, which may open new therapeutic windows for the treatment of metabolic disorders, such as obesity and type 2 diabetes.

Efficacy of local ablative therapies in patients with solid tumors treated with immune checkpoint inhibitors and oligoprogression: a single-center analysis.

The concept of oligoprogression reflects a situation where a limited number of metastatic tumor sites have progressed and other metastatic sites are under control with current systemic therapy. The optimal management of oligoprogression remains unclear. In this retrospective study, we evaluated the contribution of local ablative treatment approaches after oligoprogression to progression-free survival and response rates (RRs) in patients with renal cell carcinoma ( N : 5), nonsmall cell lung cancer ( N : 1) and melanoma ( N : 21) who received immunotherapy. We found that patients received local ablative therapies after oligoprogression had longer progression-free survival and higher RR compared to those who did not. Specifically, patients who received concurrent radiotherapy had a median survival time of 24.7 months compared to 14.5 months in those who did not. Our results suggest that local ablative therapies may have a beneficial impact on progression-free survival and RR in patients with oligoprogression who are being treated with immune checkpoint inhibitors. Further studies are needed to confirm these findings and determine the optimal use of local ablative therapies in this setting.

Hybrid Epicardial Ventricular Ablation for Arrhythmogenic Right Ventricular Cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) causes progressive fibro-fatty infiltration of the right ventricle (RV) and is associated with ventricular arrhythmias (VA). The disease progresses from the subepicardium to subendocardium; thus. epicardial ablation improves outcome in patients with recurrent VA. When percutaneous epicardial ablation is unsuccessful, a surgical approach may be required. Limited data are available for minimally invasive hybrid surgical-catheter techniques. Case: A 28-year-old man with ARVC presented with recurrent VA refractory to medical therapy following COVID-19 infection and underwent endocardial ablation with attempted epicardial ablation. He had nine or more different inducible VA morphologies at this study. Epicardial access was unsuccessful due to adhesions. Minimally invasive surgical access for epicardial ablation was scheduled as a multidisciplinary procedure in the electrophysiology suite. A left thoracoscopic approach provided intrapericardial access. Surgical ports were used to facilitate catheter placement and mapping. Relevant clinical arrhythmias were targeted, and substrate modification was performed. The patient was discharged the following morning. No subjective symptoms or implanted-device defibrillation has been required post procedure. Combined surgical and catheter-based approaches for ARVC ablation are safe and feasible. Multidisciplinary team collaboration is key for case planning and success.

Management of Ventricular Arrhythmias in Heart Failure.

Despite substantial progress in medical and device-based heart failure (HF) therapy, ventricular arrhythmias (VA) and sudden cardiac death (SCD) remain a major challenge. Here we review contemporary management of VA in the context of HF with one particular focus on recent advances in imaging and catheter ablation. Besides limited efficacy of antiarrhythmic drugs (AADs), their potentially life-threatening side effects are increasingly acknowledged. On the other hand, with tremendous advances in catheter technology, electroanatomical mapping, imaging, and understanding of arrhythmia mechanisms, catheter ablation has evolved into a safe, efficacious therapy. In fact, recent randomized trials support early catheter ablation, demonstrating superiority over AAD. Importantly, CMR imaging with gadolinium contrast has emerged as a central tool for the management of VA complicating HF: CMR is not only essential for an accurate diagnosis of the underlying entity and subsequent treatment decisions, but also improves risk stratification for SCD prevention and patient selection for ICD therapy. Finally, 3-dimensional characterization of arrhythmogenic substrate by CMR and imaging-guided ablation approaches substantially enhance procedural safety and efficacy. VA management in HF patients is highly complex and should be addressed in a multidisciplinary approach, preferably at specialized centers. While recent evidence supports early catheter ablation of VA, an impact on mortality remains to be demonstrated. Moreover, risk stratification for ICD therapy may have to be reconsidered, taking into account imaging, genetic testing, and other parameters beyond left ventricular function.

Outcomes of cavotricuspid isthmus-dependent fLutter ablation: randomized study comparing single vs multiple catheter procedures. The SIMPLE study

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation is recommended as first-line therapy for patients with symptomatic typical atrial flutter (AFl). Although the conventional multi-catheter approach is the standard of care for cavotricuspid isthmus (CTI) ablation, a single-catheter approach was recently described as a feasible alternative. Purpose The present study sought to compare safety, efficacy, and efficiency of single vs multi-catheter approach for AFl ablation. Methods In this randomized multicentre study, consecutive patients referred for AFl ablation (n= 253) were enrolled and randomized to multiple vs single-catheter approach for CTI ablation. In the single-catheter arm CTI block was confirmed analyzing PR interval (PRI) on the surface ECG as previously described by Madaffari and colleagues: briefly, PRI defined as the time between the pacing spike and the onset of the QRS complex, was measured on the surface ECG during atrial pacing (10 V, 1.5 ms) at a stable cycle length from the tip of the ablation catheter placed at 5 o’clock (medial to CTI line), 7 o’clock (lateral to CTI line), and 9 o’clock position. CTI block was assumed when: (i) the PRI at 7 o’clock was &amp;gt;80ms longer than that at pacing sites of 5, and (ii) the PRI at 9 o’clock was shorter than the PRI at 7 o’clock (Figure 1). Procedural and follow-up data were collected and compared between the two arms. Results 128 and 125 patients were assigned to the single-catheter and to the multi-catheter arms, respectively. In the single-catheter arm, procedure time was singificantly shorter (37±25 vs 48±27 minutes, p=0.002), required less fluoroscopy time (430±461 vs 712±628 seconds, p&amp;lt;0.001) and less radiofrequency time (428±316 vs 643±519 seconds, p&amp;lt;0.001), achieving a higher first-pass CTI block rate [55 (45%) vs 37 (31%), p=0.044], compared with the multi-catheter arm. After a median follow-up of 12 months, 11 (4%) patients experienced AFl recurrences [5 (4%) in the single-catheter arm and 6 (5%) in the multi-catheter arm, P=0.99]. No differences were found in arrhythmia-free survival between arms (log-rank= 0.71). Results are summarized in Figure 2. Conclusions Recurrence-free survival of the single-catheter approach for typical AFl ablation is not inferior to the conventional multiple-catheter approach, reducing procedure, fluoroscopy and radiofrequency time.

Retrograde access of the left atrium for catheter ablation using robotic magnetic navigation in atrial fibrillation: a case series

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation for which the left atrium (LA) is usually accessed by the antegrade femoral venous route and transseptal puncture. However, in rare cases, alternative routes must be used to overcome anatomical challenges. A retrograde approach via the femoral artery and by subsequently passing the aortic and mitral valve is virtually impossible using conventional catheters. Purpose To investigate the feasibility of a retrograde approach for AF ablation by robotic magnetic navigation (RMN) using floppy radiofrequency ablation catheters. Methods Between June 2014 and December 2021, a total of 6 consecutive patients underwent a total of 8 ablation procedures for AF by retrograde approach using a RMN at tour center. A magnetic catheter was introduced through the right femoral artery and manually advanced retrogradely to the aortic arch. Thereafter, it was further advanced to the LA using RMN by switching the magnets to navigation mode, passing through both aortic and mitral valve (Figure 1). Circumferential PVI was performed by antral point-by-point radiofrequency ablation and additional atrial lines were targeted when deemed necessary. Bidirectional conduction block was proven by loss of pulmonary vein potentials on the ablation catheter which automatically moved in a radial manner collecting 16 mapping points. Results The patient group (Figure 2) consisted of 4 females and 2 males with a mean age of 58,0±10,8years. 4 patients (67%) presented with persistent AF. The mean time between diagnosis and catheter ablation was 5,3±3,5 years. 2 patients (33%) had an acquired mechanical obstruction of the conventional transseptal route. The other 4 patients (67%) had an anatomical abnormality precluding conventional access to the LA. These 4 patients all underwent an unsuccessful ablation attempt via conventional approach elsewhere, before referral to our center. Patients 3 and 4 also underwent an epicardial ablation for AF respectively 1,3 and 6,2 years before catheter ablation using RMN. Patient 3 also underwent a failed attempt on manual catheter ablation using the retrograde route in another center. AF catheter ablation via retrograde access using RMN was possible in all patients and no complications occurred. The mean follow-up was 3,4±3,3 years. Conclusion Our findings indicate that a retrograde transaortic approach for catheter ablation in AF using magnetic navigation system and electroanatomical mapping is technically feasible and safe in patients with anatomical challenges precluding the use of a conventional antegrade transseptal approach. This technique may serve as an indispensable component of the management of this subgroup of patients in experienced centers.