AF Substrate Mapping and Guided Ablation
Condition: Persistent Atrial Fibrillation
MeSH terms: Atrial Fibrillation
Study type: Interventional

Summary: 
      In this study, the investigators aim to identify and characterize, by means of an EnSite
      Velocity Research Software, the electrophysiological characteristics of substrates that
      sustain AF in patients with persistent AF and to test whether ablation of such
      patient-specific substrates might improve the acute and long-term success of conventional
      catheter ablation therapy.
    

Detailed description: 
      This study is a prospective, single center, randomized, single-blind, controlled, 2-arm
      parallel group trial in Milan, Italy.

      The total duration of the study is expected to be 24 months with ~12 months of enrollment.

      Approximately 80 subjects suffering from persistent AF will be randomized in a 1:1 fashion to
      the following investigation arms:

        -  Modified circumferential pulmonary vein ablation alone (mCPVA);

        -  Substrate-targeted ablation guided by AF substrate mapping, followed by completion of
           modified circumferential pulmonary vein ablation (Substrate+ mCPVA)

             -  Ablate the areas that have fast and regular electrical activities, starting from
                the fastest cycle length (defined by Mean CL in the range of 120-250 milliseconds,
                and SD CL in the range of 1-30 milliseconds

             -  Ablate the areas that have consistent rotational or focal propagation pattern
                (defined by conduction velocity vectors)

             -  Ablate the areas that comprises the slow conduction zone of possible arrhythmia
                circuits

             -  If AF terminates during RF ablation, stimulation protocol will be used to examine
                if AF is re-inducible. If AF sustains or is re-inducible and physician decides to
                remap, mapping will be performed again for substrate-targeted ablation. If AF is
                not re-inducible, mCPVA will be completed

      Subjects will be followed up at 3, 6, 12 months.

      The primary objective of the study is to assess acute and long-term outcome of
      patient-tailored substrate-targeted ablation (Substrate) plus modified circumferential
      pulmonary vein ablation (Substrate+mCPVA) versus modified circumferential pulmonary vein
      ablation alone (mCPVA). The secondary objective of the study is to map and characterize
      electrophysiological substrates during AF, including regular and fast activities, complex
      fractionated electrograms, wave front propagation directions, and fibrosis.
    

Intervention name(s): Substrate+mCPVA; mCPVA
Intervention type(s): Device; Device
Intervention description(s): The intervention in the experimental arm includes using a research software (investigational device) to map AF substrate and guide ablation.; The intervention in the active comparator arm includes using the commercially available EnSite Velocity mapping and ablation system for modified circumferential pulmonary vein ablation.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: atrial fibrillation; mapping; substrate; ablation