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Left Atrial Appendage Electrical Isolation and Occlusion to Treat Persistent Atrial Fibrillation: A Safety and Feasibility Study (LEIO-AF)

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified June 2014 by Royal Brompton & Harefield NHS Foundation Trust.
Recruitment status was:  Enrolling by invitation
Information provided by (Responsible Party):
Royal Brompton & Harefield NHS Foundation Trust Identifier:
First received: January 3, 2014
Last updated: June 2, 2014
Last verified: June 2014

Atrial fibrillation (AF) affects as many as 1 in 16 people over the age of 65 and reduces the quality of life of large numbers of people in the UK and around the world. Catheter ablation is a minimally invasive treatment that has been developed to help eliminate AF. Recent studies have identified that a particular area of the heart, namely the left atrial appendage (LAA), which is a pouch in the left atrium (small collecting chamber of the heart), may be the main source of AF in many cases. There is a clear lack of knowledge about the structure, anatomy, function and electrical properties of the LAA, which is fundamental to furthering our understanding and management of AF.

In addition, it is well known that AF significantly increases the risk of stroke. The majority of strokes occur due to blood clots forming in the LAA. Traditionally, the most effective treatment to minimise the risk of stroke has been to thin the blood with agents such as warfarin. This therapy requires regular blood tests at much inconvenience to patients and increases the risk of bleeding complications. Recently, a large study demonstrated that use of an implanted device (Watchman®) to occlude the LAA is as effective as warfarin in preventing stroke and confers a lower mortality rate.

We aim to investigate whether it is safe and feasible to ablate the LAA and to implant a Watchman® device during the same procedure in patients who are in atrial fibrillation all of the time.

Condition Intervention
Persistent Atrial Fibrillation
Procedure: LAA electrical isolation + occlusion

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: The Safety and Feasibility of Concomitant Left Atrial Appendage Electrical Isolation and Occlusion in the Treatment of Persistent Atrial Fibrillation

Resource links provided by NLM:

Further study details as provided by Royal Brompton & Harefield NHS Foundation Trust:

Primary Outcome Measures:
  • Feasibility of concomitant LAA electrical isolation and percutaneous left atrial appendage occlusion using Watchman® device in patients with persistent atrial fibrillation [ Time Frame: At time of procedure ]
    Success rates of LAA electrical isolation and Watchman® device implantation post-LAA isolation will be determined during index procedures

  • Freedom from serious adverse events (stroke, myocardial infarction, emergency surgery, death) immediately after the procedure and during follow-up [ Time Frame: Immediately after the procedure and at 6 months ]
    Serious adverse event rate will be determined immediately after the procedure and during the 6 month follow-up period

Estimated Enrollment: 20
Study Start Date: July 2013
Estimated Study Completion Date: October 2014
Estimated Primary Completion Date: October 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: LAA electrical isolation + occlusion
Standard persistent AF ablation protocol + LAA electrical isolation + Watchman device implantation to occlude LAA
Procedure: LAA electrical isolation + occlusion
LAA electrical isolation + Watchman device implantation to occlude LAA

Detailed Description:

While catheter ablation has revolutionized the treatment of atrial fibrillation (AF), the long-term outcomes in treating persistent AF are variable, often requiring more than one procedure to maintain long-term freedom from AF. Electrical isolation of the pulmonary veins (PVs) is central to catheter ablation strategies, with the majority of paroxysmal AF recurrences being associated with reconnection of previously isolated PVs. Persistent AF is different, with recurrences being attributable to foci and or substrate outside the PVs, including the left atrial appendage (LAA). Recently, a non-randomised, consecutive study of 987 patients undergoing repeat catheter ablation for persistent (82%) and paroxysmal (18%) AF has demonstrated that almost 30% of recurrences were due to an LAA focus and that the addition of LAA electrical isolation to a standard persistent AF ablation strategy improves freedom from AF.

Percutaneous LAA occlusion has been demonstrated to be as effective as warfarin in reducing the risk of thromboembolic stroke in patients with AF. The combination of a standard AF ablation lesion set with LAA electrical isolation and LAA occlusion may be an elegant method of improving success rates of ablation for persistent AF whilst also mitigating stroke risk and reducing the bleeding risks from long-term anticoagulation. However, the feasibility and safety of concomitant endocardial electrical isolation and mechanical occlusion of the LAA is not known.

In this study we test the hypothesis that concomitant electrical isolation of the LAA and its occlusion with a Watchman device, following a standard persistent AF lesion set is feasible and safe.


Ages Eligible for Study:   18 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Age 18 - 80 years
  • Symptomatic, documented AF lasting for at least 7 days (persistent or permanent AF) refractory to at least 1 AAD and/or DCCV
  • Long-term indication to continue warfarin

Exclusion Criteria:

  • Previous ablation procedure
  • Pregnancy
  • Prior AV nodal ablation or complete heart block (CHB) with a permanent pacemaker (PPM)
  • Contraindication to anticoagulation
  • Persistent thrombus in the left atrium despite anticoagulation
  • Active malignancy
  • Expected life expectancy < 6 months
  • Cerebrovascular accident within the previous 6 months
  • Reversible causes of AF including thyroid disorders, acute alcohol intoxication, recent major surgical procedures, or trauma
  • Cardiac events including myocardial infarction (MI), percutaneous coronary intervention (PCI), valve or coronary bypass surgery within the previous 3 months
  • Prior left atrial catheter ablation with the intention to treat AF
  • Prior surgical interventions for AF such as the MAZE procedure
  • Previous heart transplant
  • Severe neuro−muscular disease
  • Creatinine clearance <30 ml/min (estimated GFR)
  • Current participation in another research study
  • Unable to understand and comply with protocol or to give written informed consent
  • Contraindication to general anaesthesia
  Contacts and Locations
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Please refer to this study by its identifier: NCT02028130

United Kingdom
Royal Brompton & Harefield NHS Foundation Trust
London, Greater London, United Kingdom, SW3 6NP
Sponsors and Collaborators
Royal Brompton & Harefield NHS Foundation Trust
Principal Investigator: Tom Wong, MD Royal Brompton & Harefield NHS Foundation Trust
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Royal Brompton & Harefield NHS Foundation Trust Identifier: NCT02028130     History of Changes
Other Study ID Numbers: 2012CI004B, 12/LO/0809
94318 ( Other Identifier: NIHR CSP )
Study First Received: January 3, 2014
Last Updated: June 2, 2014

Keywords provided by Royal Brompton & Harefield NHS Foundation Trust:
Atrial fibrillation
Left atrial appendage occlusion
Stroke prevention

Additional relevant MeSH terms:
Atrial Fibrillation
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Pathologic Processes processed this record on March 29, 2017