Effect of Empirical Left Atrial Appendage Isolation on Long-term Procedure Outcome in Patients With Persistent or Long-standing Persistent Atrial Fibrillation Undergoing Catheter Ablation
Condition: Persistent Atrial Fibrillation
MeSH terms: Atrial Fibrillation
Study type: Interventional
Phase: Phase 3

Summary: 
      The purpose of this prospective randomized study is to assess whether empirical Left Atrial
      Appendage (LAA) isolation along with the standard approach of pulmonary vein isolation (PVI)
      and ablation of extra-pulmonary triggers is superior to the standard approach alone in
      enhancing the long-term success rate of catheter ablation in persistent or long-standing
      persistent atrial fibrillation (AF) patients.
    

Detailed description: 
      Persistent (PeAF) and long-standing persistent (LSP) AF are defined as sustained AFs
      extending beyond seven days and one year respectively (1). Hypertensive, ischemic, valvular
      and other structural heart diseases most commonly underlie these arrhythmias (2) and the
      resulting abnormal atrial substrate is believed to be the major contributor toward
      perpetuation of AF in these non-paroxysmal categories. Several studies have demonstrated that
      pulmonary vein isolation (PVI) by radiofrequency catheter ablation (RFCA) though successfully
      restores sinus rhythm in most patients with paroxysmal AF; it has limited success in these
      sustained arrhythmias (3). Presence of potential trigger-generating areas in the left and
      right atrium besides pulmonary veins, with reported incidence from 3.2% to 47% (4), can be
      held responsible for this limited success. These areas include superior vena cava, ligament
      of Marshall, crista terminalis, coronary sinus, left atrial (LA) posterior wall and LA
      appendage (3). Therefore, in order to enhance the procedural-success rate, various hybrid
      measures have emerged to target the PV as well as extra-PV areas that have the ability to
      initiate or maintain AF. Several previous studies have demonstrated the prevalence of LAA
      firing in patients with recurrence of AF/AT (atrial tachycardia) after catheter ablation of
      AF (4). Embryologically, LAA is the remnant of primitive LA, which is formed by the
      adsorption of primordial PV and their branches during 4th week of embryonic development.
      Therefore, it is logical to suggest that LAA may initiate AF like pulmonary veins. In an
      earlier study conducted by our group on 987 AF patients, LAA firing was revealed to be the
      source of AF in 27% of patients and 93% of those patients were arrhythmia free 6 months after
      LAA isolation (4).

      Our study aims to compare the procedure outcome for two different ablation strategies; 1)
      standard approach of pulmonary vein isolation extended to the posterior wall down to the
      coronary sinus and to the left side of the interatrial septum along with isolation of
      superior vena cava and ablation of complex fractionated atrial electrograms (CFAE) in the
      atria and coronary sinus, 2) standard approach plus LAA isolation.

      Hypothesis: LAA isolation combined with standard ablation procedure enhances the procedural
      success rate in non-paroxysmal AF patients undergoing catheter ablation.
    

Intervention name(s): RFCA of PV and extra-PV triggers; LAA isolation along with the conventional ablation strategy
Intervention type(s): Procedure; Procedure
Intervention description(s): PVAI and isolation of extra PV triggers; PVAI + isolation of extra PV triggers + LAA isolation
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Long-standing persistent atrial fibrillation