LAA Excision With AF Ablation Versus Oral Anticoagulants for Secondary Prevention of Stroke
Condition: Atrial Fibrillation; Stroke; Systemic Embolism
MeSH terms: Stroke; Atrial Fibrillation; Embolism
Study type: Observational

Summary: 
      This cohort study aims to evaluate thoracoscopic left atrial appendage excision plus atrial
      fibrillation ablation versus oral anticoagulants for the prevention of stroke and non-central
      nervous systemic embolism in patients with atrial fibrillation and thromboembolism.
    

Detailed description: 
      Brief Summary: This cohort study aims to compare thoracoscopic left atrial appendage excision
      plus atrial fibrillation ablation versus oral anticoagulants for secondary prevention of
      stroke and non-central nervous systemic embolism in patients with atrial fibrillation and
      thromboembolism.

      Detailed Description: BACKGROUND: Atrial fibrillation (AF) is one of the most common cardiac
      arrhythmias and has been shown to be an important cause of stroke. AF is responsible for 15%
      of all strokes. Most strokes in AF are caused by cardioembolism. The left atrial appendage
      (LAA) is the dominant source of cardioembolism. The greatest priority in treating AF is
      stroke prevention. There are now 3 main approaches for prevention: (1) oral anticoagulation
      (OAC), (2) eradication of AF, and (3) exclusion of the LAA from the systemic circulation. OAC
      therapy, including warfarin and novel oral anticoagulants, effectively reduces the risk of
      stroke in AF and is currently the first line of treatment in patients with AF and one or more
      risk factors. Despite the advancements in medical therapy, the risk of stroke in patients
      with AF who undergo optimal anticoagulation therapy still remains between 2% and 5% per year,
      regardless of the agent used. The limitations of OAC include (1) patient unsuitability for
      OAC, (2) increased risk of bleeding, (3) need for monitoring optimal international normalized
      ratio (INR) levels (with warfarin), and (4) patient noncompliance. Percutaneous methods of
      ablation are widely used to attempt to eliminate AF. Approximately 20% of patients who
      underwent ablation had AF recurrence. It is because of this well-demonstrated occurrence that
      the guidelines do not recommend discontinuation of warfarin or equivalent therapies after
      ablation. Since at least 90% of all left atrial thrombi are found within the LAA, it is
      plausible that its occlusion will lead to a decreased risk of stroke in patients with AF.
      However, the evidence for surgical excision is extremely limited.

      AIM OF THE STUDY: The primary objective of this study is to evaluate whether thoracoscopic
      LAA excision plus atrial fibrillation ablation for the purpose of prevention of
      thromboembolism in patients with AF and thromboembolism is more effective and safer compared
      with OACs for reducing the composite endpoint of stroke, TIA and systemic embolism. The
      primary end point was the composite of ischemic stroke/systemic embolism/transient ischemic
      attack (TIA), major bleeding, or all-cause mortality. The secondary end point is defined as
      ischemic strokes, all strokes (including ischemic and hemorrhagic), major and fatal bleeding
      events, minor bleeding complication, all-cause mortality, cardiovascular death, and
      hospitalization due to cardiovascular or cerebral diseases.

      STUDY DESIGN: This is a single-center prospective cohort study. Adult patients with
      non-valvular AF and a previous history of ischemic stroke/systemic embolism/ TIA are eligible
      for inclusion of this study. Approximately 300 patients with paroxysmal or persistent AF and
      previous thromboembolic events will receive novel oral anticoagulant or warfarin treatment
      with a targeted INR between 2.0 and 3.0 or surgical LAA excision plus AF ablation. Follow-up
      for these patients includes visits at 3 m, 6 m, 9 m, 12 m, and every additional 6 months
      there after.
    

Intervention name(s): Thoracoscopic LAA Excision plus AF Ablation; Warfarin or Novel Oral Anticoagulants
Intervention type(s): Procedure; Drug
Intervention description(s): In this group, patients receive thoracoscopic LAA excision plus AF ablation, which means thoracoscopic left atrial appendage excision plus atrial fibrillation ablation.; In this group, patients receive warfarin or novel oral anticoagulants
Intervention MeSH terms: Warfarin; Anticoagulants
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Adult patients with non-valvular AF and a previous history of embolic events are eligible
        for inclusion of this study.
      
Biospecimen description: 
      Serum and plasma
    
Keywords: Atrial Fibrillation; Stroke; Systemic embolism; Left atrial appendage excision; Warfarin