'Understanding the Electrophysiological Substrate Underlying Persistent Atrial Fibrillation Study II (USURP AF- Study II)'

NCT04041778 | Completed

• 1 other identifier: 0689
• Study Type: observational
• Target: 17
• Locations: 1 country
• Sites: 1

Brief Summary

Atrial fibrillation (AF) is the most common type of chronic heart rhythm disease worldwide, with significant associated co-morbidities. Although there have been advances in understanding the mechanisms of AF, the underlying cause of AF and factors which perpetuate it remain incompletely understood. This is particularly the case for persistent AF (persAF). Drug treatments for persAF have a role but can have undesirable side effects with relatively limited efficacy. Furthermore, current invasive therapies for persAF remain suboptimal, requiring significant resources, and with potentially serious complications for patients. Catheter ablation is an effective treatment for paroxysmal AF. For persistent AF (persAF), however, catheter ablation does not provide similar results. This is because there remains a poor understanding of the electrophysiological mechanisms driving persAF. Part of this study aims to further explore the specific locations that represent important substrates which would guide more effective catheter ablation. There have been several different ablation approaches explored in the past (see below), however, these did not improve the outcome post procedure compared with pulmonary vein isolation alone. A pilot study has already been carried out and I aim to expand this further with a larger cohort of patients (10-20) over 2 years. In this study the investigators want to explore whether stable high dominant frequency (HDF) sites (with a high organisation index) act as potential drivers of Atrial Fibrillation. Thus, targeting these sites may results in prolongation of the cycle length and thus possible termination of the arrhythmia.

Conditions

Atrial Fibrillation Mechanisms; Persistent Atrial Fibrillation; Substrate Ablation; Pulmonary Vein Isolation; Non-contact Mapping

Outcome Measures

Primary Outcomes (3)

• Termination to sinus rhythm

  in procedure

• Slowing of cycle length by greater than or equal to 20milliseconds

  in procedure

• Termination of AF in to an organised atrial tachyarrhythmia

  in procedure

Interventions

Catheter ablation OTHER

Substrate ablation. Pulmonary vein isolation.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients will have been diagnosed with Persistent Atrial Fibrillation (persAF). They will have been listed for a first time persAF ablation as part of standard routine care.

You may qualify if:

• Must be aged 18 years or over
• Must be able to communicate in written and spoken English
• Must be able to give signed informed consent.
• All patients must be defined as having persistent atrial fibrillation (AF \> 7 days) and must be in AF at the start of the procedure.
• The patient preferably should be undergoing AF ablation for the first time, however repeat ablations can be permitted.
• The patient must be listed for persistent AF ablation as part of standard clinical care.

You may not qualify if:

• Symptoms secondary to ischaemic or valvular heart disease
• Congenital heart disease
• Previous history of a cardiac arrhythmia (other than AF, atrial tachycardia, atrial flutter).
• Previous cardiothoracic surgery
• Underlying severe respiratory disease (i.e. patient on long term oxygen therapy)
• Medical conditions which will affect cardiac rhythm, even if treated (e.g. thyroxine, etc.)
• Presence of chest deformity.
• Left atrial dilatation (L or R atrial end-diastolic dimension \> 4.5cm in any conventional plane of measurement on 2D transthoracic echocardiography).
• Presence of implantable cardiac defibrillator or pacemaker (including cardiac resynchronisation devices).

Sponsors & Collaborators

• University of Leicester: lead

Study Sites (1)

University Hospitals Leicester NHS Foundation Trust, Glenfield Hospital

Leicester, LE3 9QP, United Kingdom

Location

MeSH Terms

Conditions

Atrial Fibrillation

Interventions

Catheter Ablation

Condition Hierarchy (Ancestors)

Arrhythmias, Cardiac; Heart Diseases; Cardiovascular Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Radiofrequency Ablation; Radiofrequency Therapy; Therapeutics; Ablation Techniques; Surgical Procedures, Operative

Study Officials

• Ghulam Andre Ng, MBChB, PhD.

  Professor of Electrophysiology University Hospitals Leicester

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: CASE ONLY
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 29, 2019
• First Posted: August 1, 2019
• Study Start: July 25, 2019
• Primary Completion: September 30, 2024
• Study Completion: September 30, 2024
• Last Updated: October 1, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)