RMN-guided Ablation Research Articles

Robotic magnetic-guided catheter ablation in patients with congenital heart disease: a systematic review and pooled analysis

ABSTRACT Background Robotic magnetic navigation (RMN) has emerged as a potential solution to overcome challenges associated with catheter ablation of arrhythmias in patients with congenital heart disease (CHD). Objectives To assess safety and efficacy of RMNguided catheter ablation in patients with CHD. Design and Methods A systematic review and pooled analysis was conducted on patients with CHD who underwent RMNguided catheter ablation. Random effects models were used to generate pooled estimates with the inverse variance method used for weighting studies. Results Twentyfour nonoverlapping records included 167 patients with CHD, mean age 36.5 years, 44.6% female. Type of CHD was simple in 27 (16.2%), moderate in 32 (19.2%), and complex in 106 (63.5%). A total of 202 procedures targeted 260 arrhythmias, the most common being macroreentrant atrial circuits. The mean procedural duration was 207.5 minutes, with a mean fluoroscopy time of 12.1 minutes. The pooled acute success rate was 89.2% [95% CI (77.8%, 97.4%)]. Freedom from arrhythmia recurrence was 84.5% [95% CI (72.5%, 94.0%)] over a mean follow-up of 24.3 months. The procedural complication rate was 3.5% with no complication attributable to RMN technology. Conclusion RMN-guided ablation appears to be safe and effective across a variety of arrhythmia substrates and types of CHD.

Comparison of the Mid-Term Outcomes of Robotic Magnetic Navigation-Guided Radiofrequency Ablation versus Cryoballoon Ablation for Persistent Atrial Fibrillation.

Introduction: Currently, numerous ablation techniques are available for atrial fibrillation (AF), in addition to manual radio frequency ablation. The aim of this prospective, non-randomized concurrent controlled trial was to compare the mid-term efficacy and procedural outcomes of persistent AF (PerAF) using cryoballoon (CB) and robotic magnetic navigation (RMN). Methods: Two hundred PerAF patients were assigned, in a 1:1 ratio, to undergo catheter ablation using RMN (RMN group) or CB (CB group). The primary endpoint was freedom from AF recurrence following a 3-month period after the index ablation. The secondary endpoint was peri-procedural outcomes, including the total procedure time, left atrial procedure time, fluoroscopy time, and fluoroscopy dose. The Two-step cluster analysis was used to determine the efficacy of RMN and CB between the different groups. The Cox proportional hazard model and restricted cubic spline were used to determine predictors for AF recurrence. Results: At the mean follow-up of 28.1 ± 9.7 months, the primary endpoint was achieved in 71 PerAF patients in the RMN group and in 62 PerAF patients in the CB group (71% vs. 62%, p = 0.158). Compared with CB, RMN-guided ablation led to a longer procedure time (p < 0.001), but with less radiation (p < 0.001). Cluster analysis returned two clusters of patients and RMN was favorable for one cluster (p = 0.037), in which more patients presented with diabetes mellitus and smaller left atria. Conclusions: For patients with PerAF, CB is generally equivalent to RMN-guided ablation with regard to overall efficacy. RMN-guided ablation could be favorable in specific patient populations presenting with diabetes mellitus and smaller left atria.

Utilization of steerable sheath improves the efficiency of atrial fibrillation ablation guided by robotic magnetic navigation compared with fixed-curve sheath.

BackgroundThe objective of this study was to assess the impact of steerable sheaths compared with fixed‐curve sheaths on the procedural outcomes of atrial fibrillation (AF) ablation guided by robotic magnetic navigation (RMN).Methods and ResultsIn this retrospective case−control study, 110 patients scheduled for AF catheter ablation were enrolled and divided into two groups. Fifty‐five patients (paroxysmal, 70%) were treated with RMN‐guided ablation utilizing a steerable sheath and another 55 patients (paroxysmal, 70%) were ablated with RMN using a fixed‐curve sheath. Clinical characteristics were similar between the two groups. Compared with the fixed‐curve sheath group, the steerable sheath group procedure time (111.9 ± 25.2 vs. 90.4 ± 20.7 min, p < .001) and radiofrequency (RF) time (35.9 ± 9.0 vs. 30.5 ± 7.4 min, p < .001) were significantly shortened. Additionally, the navigation index was significantly improved (0.41 ± 0.06 vs. 0.48 ± 0.08, p < .001) in the steerable sheath group. By employing a large catheter loop for targeting the right pulmonary veins (PVs), the steerable sheath group significantly reduced the RF delivery time (15.0 ± 3.0 vs. 12.0 ± 2.1 min, p < .001) during right‐side PV isolation (PVI). However, total fluoroscopy time was similar between the two groups (5.6 ± 2.6 vs. 5.0 ± 2.0 min, p > .05). Acute PVI success rates were similar between the two groups. No major or minor complications occurred in either group.ConclusionAppropriate utilization of steerable sheath technology can improve the efficiency of AF ablation guided by RMN, primarily by reducing the total procedure and RF delivery times of right‐side PVI without compromising safety.

Long-Term Efficacy and Impact on Mortality of Remote Magnetic Navigation Guided Catheter Ablation of Ventricular Arrhythmias.

Remote magnetic navigation (RMN) facilitates ventricular arrhythmia (VA) ablation. This study aimed to evaluate the long-term efficacy of RMN-guided ablation for ventricular tachycardia (VT) and premature ventricular contractions (PVC). A total of 176 consecutive patients (mean age 53.23 ± 17.55 years, 37% female) underwent VA ablation for PVC (132 patients, 75%) or VT (44 patients, 25%). The cohort consisted of 119 patients (68%) with idiopathic VA, 31 (18%) with ischemic (ICM), and 26 (15%) with dilated cardiomyopathy (DCM). VA recurrence was observed in 69 patients (39%, mean age 51.71 ± 19.91 years, 23% female) during a follow-up period of 5.48 years (first quartile 770.50 days, second quartile 1101.50 days, third quartile 1615.50 days). Left ventricular ejection fraction <40% lead to a significantly increased risk for VA (p = 0.031*). Multivariate analyses found DCM to be an independent predictor (IP) for VA recurrence (p < 0.001*, hazard ratio (HR) 3.74, confidence interval (CI) 1.58–8.88). ICM resulted in a lower increase in VA recurrence (p = 0.221, HR 1.49, CI 0.79–2.81). Class I/III/IV antiarrhythmic drug therapy (AADs) was also identified as IP for recurrence (p = 0.030*, HR 2.48, CI 1.11–5.68). A total of 16 patients (9%) died within the observational period. RMN-guided ablation of VA lead to acceptable long-term results. An impaired LV function, DCM, and AADs were associated with a significant risk for VA recurrence. Personalized paths are needed to improve efficacy and outcome.

Novel strategy of remote magnetic navigation-guided ablation for ventricular arrhythmias from right ventricle outflow tract

The optimized strategy to further increase the success rate of ablation for ventricular arrhythmias (VAs) from the right ventricular outflow tract (RVOT) is challenging. Recent studies have shown that the pulmonary sinus cusp (PSC) region may be the origin of certain RVOT VAs. We evaluated the efficacy of preferential ablation below the pulmonary valve (PV) and alternated radiofrequency delivery in the PSC using remote magnetic navigation (RMN). Sixty-five (65) consecutive patients experiencing VAs with RVOT-like appearance were included in this study. Mapping and ablation were preferentially performed below the PV. Ablation in the PSC would only be attempted when intensified ablation below the PV could not eliminate VAs. Finally, if ablation in the RVOT region failed, the aortic sinus cusp (ASC) would be mapped. Sixty-one (61) of 65 (93.8%) patients achieved procedural success. Except 7 cases of which the VAs were ablated in the ASC, the rest 54 VAs were thought to be originate from the RVOT region. Fifty (50) of 54 VAs were successfully ablated below the PV, and in the presence of a local special signal in the bipolar electrogram a more aggressive ablation was required. Subsequent ablation in the PSC with assistance of the RMN system achieved success in the remaining 4 patients. No complications occurred in this study. Our strategy of using RMN-guided ablation below the PV for VAs of RVOT origin was proved to be effective. PSC mapping and ablation using a magnetic catheter may provide the optimal strategy for treating these types of arrhythmias.

Procedural outcomes and learning curve of cardiac arrhythmias catheter ablation using remote magnetic navigation: Experience from a large-scale single-center study.

BackgroundRemote magnetic navigation (RMN)‐guided ablation has become an inspiring method of catheter ablation for tachyarrhythmias.HypothesisData from a large‐scale single center may provide further insight into the safety of and the learning curve for RMN‐guided ablation.MethodsA total of 1003 catheter ablation procedures using RMN for conditions including supraventricular ventricular tachycardia, atrial tachyarrhythmias, and premature ventricular contraction/ventricular tachycardia (PVC/VT) were retrospectively analyzed from an ablation registry. Procedural outcomes, including procedure time, mapping time, X‐ray time, and RF time, were assessed. The complications were classified into two categories: major and minor. A subanalysis was used to illustrate the learning curve of RMN‐guided ablation by assessing procedure time and total X‐ray time of 502 atrial fibrillation (AF) ablation procedures.ResultsAmong these procedures, 556 (55.4%) were AF and 290 (28.9%) were PVC/VT. Electrical pulmonary vein isolation was achieved in 99.0% of AF procedures, and acute success reached 90.3% in PVC/VT procedures. The overall complication rate was 0.5%. In the subanalysis of AF procedures, the overall procedure time and X‐ray time of procedures were short (125.9 ± 54.6 and 5.3 ± 3.9 minutes, respectively) and proceeded to decrease from the initial 30 procedures to about 300 procedures, where the learning curve reached plateau, demonstrating maximum procedure efficiency.ConclusionsRMN‐guided ablation is safe, as verified by very low overall complication rate and reduced X‐ray time. In our study, even the first AF procedures had a relatively low procedure time and total X‐ray time, and procedure efficiency improved during the learning curve.

Remote magnetic navigation facilitates the ablations of frequent ventricular premature complexes originating from the outflow tract and the valve annulus as compared to manual control navigation

ObjectiveThe purpose of this study was to assess the role of remote magnetic navigation (RMN) in the ablation of ventricular premature complexes (VPCs) arising from outflow tracts (OT) and valve annuli by comparing to manual control navigation (MCN). MethodsA total of 152 patients with frequent VPCs were prospectively enrolled. 64 (42%) patients underwent ablation guided by RMN. Acute success rate was defined as the complete elimination and non-inducibility of clinical VPCs during the procedure. ResultsOverall, acute success rate of RMN group was not different from MCN group (87.5% vs 84.1%, p = 0.56). Compared to MCN group, the fluoroscopic time of OT-VPCs ablation in the RMN group was significantly reduced by 67% (2.9 ± 2.3 min vs 8.9 ± 9.7 min, p = 0.006), and the ablation applications in successful cases were significantly reduced (11 ± 7 vs 15 ± 11, p = 0.018). Compared to MCN, RMN significantly decreased ablation applications (15 ± 9 vs 23 ± 9, p = 0.013) in the acute success rates of ablating VPCs of valve annulus, and has a trend of a higher success rate for VPCs arising from tricuspid annulus (10/11 vs 7/12, p = 0.193). No complications occurred in the RMN group. Three cases of cardiac tamponade and one case of transient atrioventricular block occurred in the MCN group (p = 0.22). After a mean follow up of 16.2 months, 2/56 and 3/74 patients had a recurrence of VPCs in the RMN group and MCN group respectively (p = 0.75). ConclusionsWhen compared to MCN, RMN-guided ablation for VPCs was just as effective and safe, with the added benefit of reduced fluoroscopic time and fewer ablation applications.

Long-term outcomes of remote magnetic navigation for ablation of supraventricular tachycardias.

Little is known about the long-term outcomes of catheter ablation of supraventricular tachycardia (SVT) using remote magnetic navigation system (RMN). One hundred twenty patients underwent catheter ablation of SVTs with RMN (Niobe, Stereotaxis, USA): atrioventricular nodal re-entrant tachycardia (AVNRT; n = 59), atrioventricular re-entrant tachycardia (AVRT; n = 45), and focal atrial tachycardia (AT, n = 16). The outcome of AVRT with right free wall accessory pathway was compared with those of a group of 26 consecutive patients undergoing manual ablation. Mean follow-up period was 2.2 ± 1.4 years. Overall arrhythmia-free survival was 86%; AVRT (77%), AVNRT (96%), and focal AT (71%). After the learning period (initial 50 cases), procedural outcomes had improved for AVRT and AVNRT (91% in overall group, 90% in AVRT group, 100% in AVNRT group, and 68% in focal AT group). The recurrence-free rate was higher for the free wall accessory pathways than those of the other sites (92 vs. 73%, log-rank P = 0.06). Furthermore, when it is confined for the right free wall accessory pathway, RMN showed excellent long-term outcome (7/7, 100 %) compared to the results of manual approach (18/26, 69.2%, log-rank P = 0.07). RMN showed favorable long-term outcomes for the ablation of SVT. In our experience, RMN-guided ablation may be associated with a higher success rate as compared to manual ablation when treating right-sided free wall pathways.

Acute and long term outcomes of catheter ablation using remote magnetic navigation for the treatment of electrical storm in patients with severe ischemic heart failure

BackgroundCatheter ablation with remote magnetic navigation (RMN) can offer some advantages compared to manual techniques. However, the relevant clinical evidence for how RMN-guided ablation affects electrical storm (ES) due to ventricular tachycardia (VT) in patients with severe ischemic heart failure (SIHF) is still limited. MethodsForty consecutive SIHF patients (left ventricular ejection fraction, 21±6.9%) presenting with ES underwent ablation using RMN. All the patients received implantable cardioverter-defibrillators (ICDs) either before or after ablation. Acute ablation success was defined as noninducibility of any sustained monophasic VT at the end of the procedure. Long-term analysis addressed VT recurrence, ICD therapies and all-cause death. ES was acutely suppressed by ablation in all patients. ResultsAcute ablation success was obtained in 32 of 40 (80%) patients. The procedure time and fluoroscopy time were 105±27min and 7.5±4.8min respectively. No major complications occurred during procedures. During a mean follow-up of 17.4months, 19 patients (47.5%) remained free of VT recurrence. The percentage of patients receiving ICD shocks after ablation was lower than before ablation (30% vs 69%, P<0.01). The mean number of ICD shocks per individual per year was reduced from 4.3 before ablation to 1.9 after ablation (P<0.05). Ten patients died during follow-up. ConclusionsAcute catheter ablation with RMN is safe and effective to suppress ES in SIHF patients. RMN-guided catheter ablation can prevent VT recurrence and significantly reduce ICD shocks, suggesting that this strategy can be used as an alternative therapy for VT storm in SIHF patients with ICDs.

Remote magnetic navigation for circumferential pulmonary vein ablation: single-catheter technique or additional use of a circular mapping catheter?

Remote magnetic navigation (RMN) is utilized for catheter guidance during pulmonary vein ablation (PVA). We aimed to determine whether the additional use of a circular mapping catheter (CMC) influences efficacy and outcome of RMN-guided PVA. A total of 80 consecutive subjects (65 % male, age 62 ± 9 years) underwent circumferential PVA with a 3D mapping system and an RMN-guided irrigated catheter. Procedural endpoint was complete PV isolation (PVI), total radiofrequency (RF) time >60 min, or procedure duration >5 h. PVI was defined as an entrance and/or exit block, diagnosed with a CMC within the PV ostium or by pacing via the roving RMN-guided catheter (single-catheter technique). Prolonged Holter monitoring after 3 and 6 months was used to detect atrial tachyarrhythmia (AT/AF) recurrences. Complete PVI was achieved in 56 % (45/80) of all subjects (isolated PVs per patient, 3.1 ± 1.2; RF time, 56.3 ± 17.2 min; procedure duration, 3.8 ± 0.8 h). Prospective validation of the single-catheter technique for diagnosing PVI demonstrated high concordance (94 %) with blinded CMC results. CMC use in first-time PVA was associated with similar total RF and procedure times but higher PV isolation rate. Upon multivariate analysis, CMC use, female gender, left PV, smaller PV ostium and repeat PVA predicted PVI during RMN-guided ablation. Persistent AF and mitral regurgitation at baseline and the number of non-isolated PVs predicted AT/AF recurrence during follow-up. Concomitant CMC use for first-time, RMN-guided PVA is associated with similar procedure duration but higher PV isolation rates as compared to a single-catheter approach. Since the number of isolated PVs predicts freedom from AT/AF, CMC utilization appears advisable for first-time, RMN-guided PVA.