Zero Fluoroscopy Voltage Guided vs. Linear CTI Ablation
brief summary
Catheter ablation of the cavo-tricuspid isthmus (CTI) is the curative first-line therapy for typical atrial flutter. Currently, two approaches are used in clinical practice. In contrast to the conventional linear ablation approach, the Maximum voltage-guided (MVG) strategy aims to limit ablation to high voltage areas (HVAs) representing the detectable correlate of relevant conducting bundles. Data from registries show that the MVG technique is sufficient to reach comparable clinical outcome with significantly shorter ablation duration when compared to the conventional linear strategy. Despite growing evidence, however, data from properly powered prospective randomized trials are lacking and the linear approach still remains standard. In addition, data on radiation exposure are controversial. As a substrate-based approach, the MVG strategy requires detailed mapping and signal analysis for identification of the individual architecture and exactly targeted energy application. However, the spatial mapping resolution of large tip catheters is limited. The use of the MicroFidelity catheter technology (IntellaMiFi) with high resolution mini-electrodes at the 8 mm catheter tip can be expected to further improve the feasibility of a voltage-guided approach. In addition, the MVG approach theoretically may encompass an increased risk for clinically inapparent reconduction. A prospective study with predefined invasive re-evaluation of persistent CTI block is needed to further evaluate this issue. Objective of this prospective randomized study is evaluate the performance of the micro-sensor technology for zero-fluoroscopy voltage-guided ablation of typical atrial flutter (AFL) compared with a population undergoing conventional linear ablation including a predefined invasive re-evaluation of persistent CTI block in addition to clinical follow-up. The study has been approved by the responsible ethics committee.
detailed description
Rationale:
Catheter ablation of the CTI represents the established curative first-line treatment for typical AFl. Although the acute and chronic efficacy is high, conventional ablation is still time consuming, requires a considerable amount of radiation as reported even in the most recent trials and treatment failure occurs.
The MVG catheter ablation of the CTI aims to limit energy delivery by selectively treating conductive bundles. Compared to the conventional linear strategy, a reduction of ablation and procedural time had been shown for the MVG technique. For several reasons, however, the current evidence is still not considered to be robust enough to suggest a general change in the ablation approach:
* Despite a reduction in ablation requirements, the additional time needed for voltage mapping often prolongs the total procedure duration. * The spatial mapping resolution of large tip catheters, most often used for CTI-ablation is limited. * Catheter positioning and CTI ablation is still guided by fluoroscopy with the well-known potential harm in the majority of electrophysiological centers. There are conflicting data for the MVG approach regarding radiation duration. * The MVG approach theoretically encompasses an increased risk for clinically inapparent reconduction. A prospective study with predefined invasive re-evaluation of persistent CTI block is lacking.
Aims of the study:
MicroFidelity catheter technology was introduced to enhance the spatial resolution of large tip catheters and may facilitate zero-fluoroscopy substrate-guided ablation by high-resolution (HR) electroanatomic mapping (EAM) and precisely targeted energy application.
This study is designed to prospectively evaluate safety and efficacy of the stepwise maximum voltage mapping guided CTI ablation strategy ("MVG") using IntellaMiFi technology compared with a randomized cohort undergoing conventional linear CTI ablation (control).
Beyond procedural efficacy (main hypothesis) and safety patients outcome will be evaluated
1. by electrophysiologic diagnostic reevaluation of the ablation success after 3 months, 2. by clinical assessment and Holter-monitoring during 6 and 12-month follow-up. Furthermore, we aim to validate efficacy and safety of three-dimensional EAM- guided CTI ablation without the use of fluoroscopy as standard approach in clinical routine.
official title
A Zero Fluoroscopy Maximum Voltage Guided Stepwise Approach Using IntellaMiFi Technology Compared to Linear Ablation of the Cavotricuspid Isthmus for Typical Atrial Flutter: the ZERO MAGIC Trial