Study design of the man and machine trial: a prospective international controlled noninferiority trial comparing manual with robotic catheter ablation for treatment of atrial fibrillation.

BACKGROUND: Pulmonary vein isolation (PVI) has become the cornerstone procedure for the treatment of symptomatic drug-resistant atrial fibrillation (AF). At the present time, circumferential PVI (CPVI) using irrigated radiofrequency (RF) is the mostly used ablation technique. However, for CPVI, precise catheter navigation and excellent catheter stability is crucial thereby requiring experienced operators. Robotic navigation systems have been introduced to facilitate catheter navigation and to improve catheter stability, therefore potentially increasing procedural success and making CPVI accessible to less experienced operators. To date, no prospective randomized trial has evaluated the efficacy and safety of CPVI using RNS compared to manually performed ablation. METHODS: In this prospective international multicenter noninferiority trial, 258 patients with either paroxysmal or short-standing persistent AF will be randomized for comparison of PVI using either manual or robotic ablation. In all patients, CPVI will be performed using irrigated RF ablation in combination with a 3D mapping system. The primary endpoint of the trial is the absence of AF or atrial tachycardia without antiarrhythmic drug therapy during 12-month follow-up. Secondary endpoints will be evaluation of periprocedural complications and procedural data such as procedure time, fluoroscopy time, as well as the incidence of esophageal injury assessed by endoscopy within 48 hours after the procedure. CONCLUSION: The "Man and Machine Trial" is the first prospective international randomized controlled multicenter noninferiority trial to compare manually performed CPVI with robotically navigated CPVI, evaluating both the safety and efficacy of the 2 techniques during a 12-month follow-up period.

Worldwide experience with the robotic navigation system in catheter ablation of atrial fibrillation: methodology, efficacy and safety.

INTRODUCTION: The Hansen Robotic system has been utilized in ablation procedures for atrial fibrillation (AF). However, because of the lack of tactile feedback and the rigidity of the robotic sheath, this approach could result in higher risk of complications. This worldwide survey reports a multicenter experience on the methodology, efficacy, and safety of the Hansen system in AF ablations. METHODS AND RESULTS: A questionnaire addressing questions on patient's demographics, procedural parameters, ablation success rate and safety information was sent to all centers where more than 50 robotic AF ablation cases have been performed. From June 2007 to December 2009, 1,728 procedures were performed at 12 centers utilizing the Hansen robotic navigation technology. The overall complication rate was 4.7% and the success rate was 67.1% after 18 ± 4 months of follow-up. In 5 low volume centers there appeared to be a learning curve of about 50 cases (complication rate 11.2% for the first 50 cases vs 3.7% for the 51-100 cases; P = 0.044) and a trend showing a decrease of complication rate with increasing case volume. However, in the remaining 7 centers no learning curve was present and the complication rate was stable over time (3.7% for the first 50 cases vs 3.6% for the 51st case thereafter; P = 0.942). CONCLUSION: The Hansen robotic system can be used for AF ablation safely. In low volume centers, there appeared to be a learning curve of the first 50 cases after which the complication rate decreased. With a higher case volume, the success rate increased.

Remote robotic catheter ablation for atrial fibrillation: how fast is it learned and what benefits can be earned?

INTRODUCTION: Recently, results describing pulmonary vein isolation (PVI) on patients using a robotic navigation system (RNS) in a high-volume center specialized in pulmonary vein isolation were published. The main purpose of this prospective study was to evaluate the learning curve of new users of RNS in a community hospital and to address the effectivity of RNS in electrophysiological settings with fewer patients. Radiation times, procedural times, feasibility, and safety with the RNS were assessed. METHODS: PVI using the RNS was performed on 100 consecutive patients with symptomatic paroxysmal (n = 56, 56%) or persistent atrial fibrillation (AF). To assess the learning curve of practitioners with first-time use of RNS, patients were divided into four groups of 25 patients each (Q1-Q4). Procedural times as well as radiation times, complications, and outcome after a 6-month follow-up period were assessed for each quartile. All patients were ablated by the same physician. RESULTS: Comparing the four patient groups, a continuous and significant reduction of procedural and radiation times was seen in the first 75 patients (Q1-Q3), whereas no further improvement was seen in the consecutive patients (Q3-Q4). One pericardial tamponade occurred in the course of 100 patients (1%). Overall success rate after a 6-month follow-up period was 74% in patients with paroxysmal and persistent AF. Comparing the four quartiles there was a higher but non-significant number of patients with freedom of atrial fibrillation after a 6-month follow-up in the subsequent groups (Q2-Q4) when compared to group 1. CONCLUSIONS: This data suggest that RNS is feasible and safe when performed in a community hospital with a significant reduction of radiation times and procedure times within the first 75 patients and with similar success and complication rates as compared to high-volume centers.

Persistent iatrogenic atrial septal defect after a single-puncture, double-transseptal approach for pulmonary vein isolation using a remote robotic navigation system: results from a prospective study.

AIMS: Persistent iatrogenic atrial septal defect (iASD) after transseptal puncture for pulmonary vein isolation (PVI) has been described recently as a complication of PVI. No data exists evaluating systematically the incidence and clinical implications of iASDs after PVI using a remote robotic navigation system (RNS) with sheaths with a distinct larger outer diameter. METHODS AND RESULTS: In this prospective study, 40 patients with either paroxysmal (n = 22, 55%) or persistent symptomatic atrial fibrillation were treated with circumferential PVI using an RNS. In all patients, a single-puncture, double-transseptal approach was used to access the left atrium. Transoesophageal echocardiography was performed before and the day after PVI as well as after a 3 and 6 months follow-up (FU). The day after ablation an iASD was detected in 38 of 40 (95%) patients with a mean diameter of 3.45 +/- 1.5 mm. At 6-month FU, the iASDs were closed in 30 of 39 (78.9%) patients. During the 6-month FU period, no patient died or suffered from cerebral or cardiac embolism. CONCLUSION: After a single-puncture, double-transseptal approach for PVI using the RNS, iASDs show a high spontaneous closure rate of 78.9% after a 6-month FU period. Persistent iASDs following PVI with the RNS are not associated with an increased rate of paradoxical embolism or with relevant shunting.

Recurrence-plot-based measures of complexity and their application to heart-rate-variability data.

The knowledge of transitions between regular, laminar or chaotic behaviors is essential to understand the underlying mechanisms behind complex systems. While several linear approaches are often insufficient to describe such processes, there are several nonlinear methods that, however, require rather long time observations. To overcome these difficulties, we propose measures of complexity based on vertical structures in recurrence plots and apply them to the logistic map as well as to heart-rate-variability data. For the logistic map these measures enable us not only to detect transitions between chaotic and periodic states, but also to identify laminar states, i.e., chaos-chaos transitions. The traditional recurrence quantification analysis fails to detect the latter transitions. Applying our measures to the heart-rate-variability data, we are able to detect and quantify the laminar phases before a life-threatening cardiac arrhythmia occurs thereby facilitating a prediction of such an event. Our findings could be of importance for the therapy of malignant cardiac arrhythmias.