Ablation of Clinical Ventricular Tachycardia Versus Addition of Substrate Ablation on the Long Term Success Rate of VT Ablation
Condition: Ventricular Tachycardia
MeSH terms: Tachycardia; Tachycardia, Ventricular
Study type: Interventional
Phase: Phase 3

Summary: 
      This study aims to assess whether a combined technique of substrate ablation and ablation of
      the clinically presenting VT at the site of early activation is superior to ablation of the
      clinically presenting VT alone, in enhancing long-term success of VT ablation.
    

Detailed description: 
      Background: VT is found mostly in patients with structural heart disease. It is classified
      using morphological criteria (monomorphic or polymorphic), duration of arrhythmia (sustained
      or non-sustained) or the mechanism of arrhythmia formation (re-entry, increased automation or
      triggered activity). The therapeutic approach and prognostic estimates of these different
      types of VT depend to a great degree on the mechanistic basis of the disease as well as the
      extent of myocardial damage and success of the therapy is measured by the absence of
      recurrence.

      Myocardial infarction with subsequent induction of VT is observed as a consequence of
      coronary artery disease (CAD). The infarct regions that are morphologically and electrically
      diseased can be arrhythmogenic and may form the substrate for macro-reentrant VT.

      Although antiarrhythmic drugs remain the primary form of therapy for VT, non-pharmacologic
      techniques like implantable cardioverter-defibrillator (ICD) and catheter ablation (CA) are
      becoming increasingly popular because of advancement in technology as well as an increase in
      desire among patients to eliminate the arrhythmia with ablation rather than suppressing it
      with drugs. ICDs and CA effectively terminate VT on a short-term basis; but multiple
      morphologies, hemodynamic instability and non-inducibility limit the long-term success rate
      of CA. The 'substrate mapping' approach defines areas of ventricular scar which can be
      potential VT sources. Several studies on small groups of patients have shown that successful
      ablation of VT substrates either reduces the recurrence of VT to 19- 50% or reduces the
      frequency of recurrence as well as the requirement of anti-arrhythmic drugs (AADs).

      Study design:

      This study is a multicenter, randomized, open label, parallel-arm clinical trial. A total of
      120 post-myocardial infarction patients will be randomized at a 1:1 ratio into 2 groups:

        1. ablation targeting the clinically presenting VT at the site of early activation only, or

        2. ablation targeting the clinically presenting VT at the site of early activation plus
           substrate-based RF ablation

      Follow-up:

      Patients will undergo ICD interrogation at 3, 6 and 12 months to collect VT episode data, VT
      symptom assessment, complication assessment and AAD records. Management of AADs will be at
      the discretion of the physician.
    

Intervention name(s): Radiofrequency Catheter Ablation (RFCA); Radiofrequency Catheter Ablation (RFCA)
Intervention type(s): Procedure; Procedure
Intervention description(s): RFCA of clinical VT; RFCA of clinical VT as well as VT substrates
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment