Substrate abLatIon as Concomitant trEatment for Left Atrial Macroreentrant Tachycardia (SLICE-LAMRT)

Substrate abLatIon as Concomitant trEatment for Left Atrial Macroreentrant Tachycardia - SLICE LAMRT

SLICE-LAMRT is a multicenter, prospective, randomized, double-blind trial that will be carried out in patients older than 18 years with atypical flutter suspected to be of left atrial origin. The aim of this trial is to evaluate the safety and superiority of a substrate-guided ablation procedure vs the conventional strategy guided by electrical activity.

The composite primary endpoint is time to first episode of sustained atrial arrhythmia in the absence of pharmacological antiarrhythmic treatment or new ablation.

Study Overview

• Status: Recruiting
• Conditions: Atrial Fibrillation
• Intervention / Treatment: Procedure: Line Set Strategy; Procedure: Conventional strategy

Detailed Description

Left atrial macroreentrant tachycardias (LAMRT), also known as left atrial flutter, represent a small percentage of supraventricular arrhythmiass. These tachycardias occur due to reentrant circuits, that is, electrical activation that occurs around natural anatomical obstacles or scar areas.

Classically, by analogy with ventricular tachycardias, these tachycardias are approached by delimiting the circuit (locating the anatomical and functional obstacles), searching for critical areas for their maintenance (isthmuses, generally of slow conduction) and creating controlled lesions that interrupt these circuits (catheter ablation). This requires electromagnetic mapping systems and uses programmed stimulation techniques. This approach treats flutter(s) present at the time of ablation to prevent recurrence. However, it is not uncommon for these patients to develop new macroreentrant circuits during the subsequent clinical course, so the recurrence rate of atrial arrhythmias in this population is relatively high.

The goal of this trial is to determine whether substrate-guided ablation of atypical atrial flutter is superior to electrical activation-guided ablation in reducing the recurrence of atrial arrhythmias and increasing the time to first recurrence of atrial fibrillation, atrial flutter, or atrial tachycardia. The investigators hypothesize that ablation not only of inducible tachycardias during the ablation procedure, but guided by the substrate that is most often key to the maintenance of these tachycardias, is superior to conventional treatment in reducing associated clinical events.

• Study Type: Interventional
• Enrollment (Estimated): 128
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Daniel Rodríguez Muñoz, MD, PhD; Phone Number: +34 917792742; Email: danielantonio.rodriguez@salud.madrid.org

Study Locations

• Spain
  • Madrid, Spain, 28041
    • Recruiting
    • Hospital Universitario 12 de Octubre
    • Contact: Daniel Rodríguez Muñoz, MD, PhD; Phone Number: +34 917792742; Email: danielantonio.rodriguez@salud.madrid.org

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Atypical flutter with positive F wave in V1, suspected left atrial origin.
• Age ≥ 18 years
• Capacity to understand the nature of the study, legal ability and willingness to give informed consent.

Exclusion Criteria:

• Simultaneous participation in a different trial.
• Presence of congenital heart disease.
• Suspected flutter of right origin or related to atriotomy scar from previous cardiac surgery.
• NYHA IV functional class at the time of recruitment.
• Contraindication to chronic anticoagulation or allergy/intolerance to heparin.
• Uncontrolled hyperthyroidism.
• Life expectancy less than 18 months.
• Presence of heart disease that is expected to require surgery or heart transplantation within 18 months.
• Pregnancy or the prospect of it in the next 18 months.
• Left atrium without pathological substrate: area ≥ 4 cm2 of low voltages (<0.5 mV) in the left atrium.
• Severe fragility (Clinical Frailty Score ≥ 7).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Line set strategy; Pulmonary vein isolation, roof line, posterior wall isolation (posterior box), anterior septal line and cavo-tricuspid isthmus.	Procedure: Line Set Strategy; Substrate-guided ablation procedure of atypical atrial flutter
Active Comparator: Conventional strategy; Mapping and ablation of the present flutter and those that could be induced later until sinus rhythm is obtained.	Procedure: Conventional strategy; Electrical activation-guided ablation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Composite primary endpoint	Time to first episode of sustained atrial arrhythmia in the absence of pharmacological antiarrhythmic treatment or new ablation	18 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Major complications	Death, stroke/systemic embolism, tamponade, during the procedure and immediate post-procedure.	First month
Unplanned cardiovascular hospitalisation	Unplanned cardiovascular hospitalisation	18 months
Unplanned hospitalization for any cause.	Unplanned hospitalization for any cause.	18 months
All-cause mortality	Mortality due to any cause	18 months
Cardiovascular mortality	Mortality due to cardiovascular causes	18 months
Proportion of patients without recurrence of atrial arrhythmia at 18 months	Maintainance of sinus rhythm by ablation, without requiring electrical cardioversion.	18 months
Procedure duration	Procedure duration, radiofrequency time, left atrial time (from transseptal puncture to left atrial catheter removal), fluoroscopy time.	In the procedure

Collaborators and Investigators

• Sponsor: Hospital Universitario 12 de Octubre
• Investigators: Study Chair: Fernando Arribas Ynsaurriaga, MD, PhD, Hospital Universitario 12 de Octubre

Study record dates

Study Major Dates

• Study Start (Actual): June 15, 2021
• Primary Completion (Estimated): January 1, 2026
• Study Completion (Estimated): January 1, 2026

Study Registration Dates

• First Submitted: April 24, 2023
• First Submitted That Met QC Criteria: April 24, 2023
• First Posted (Actual): May 6, 2023

Study Record Updates

• Last Update Posted (Actual): July 11, 2023
• Last Update Submitted That Met QC Criteria: July 9, 2023
• Last Verified: July 1, 2023

More Information

Terms related to this study

• Keywords: Ablation; Scar; Atypical flutter; Pulmonary veins; Atypical atrial flutter; Macroreentrant Tachycardia
• Additional Relevant MeSH Terms: Pathologic Processes; Heart Diseases; Cardiovascular Diseases; Arrhythmias, Cardiac; Cardiac Conduction System Disease; Atrial Fibrillation; Tachycardia
• Other Study ID Numbers: SLICE-LAMRT

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No