Effect of Balloon Cryoablation on Left Atrial Function
Condition: Atrial Fibrillation
MeSH terms: Atrial Fibrillation
Study type: Interventional

Summary: 
      Atrial fibrillation is a common and disabling irregular heart rhythm, that affects 1 to 1.5
      million Americans. Recent clinical experience with the Medtronic Arctic Front™ Cardiac
      CryoAblation Catheter System suggests that it can be used to isolate the pulmonary veins
      (PVs) safely and effectively in patients with AF, thereby reducing or eliminating the
      recurrence of AF.3-4 However, the very large ablative surface of this balloon ablation
      catheter raises the possibility that this technique may damage extensive areas of the atrial
      myocardium.

      The LA is an elastic chamber, designed to expand and contract with ease to accommodate the
      influx and outflow of blood, while maintaining relatively low pressure. When exposed to
      stress or injury, whether acute or chronic, the LA may lose much of its elasticity, resulting
      in overall dilation accompanied by fibrosis in some cases. Overall, this may potentially
      result in diminution of LA mechanical function (both systolic contractile function, and
      diastolic relaxation function). In addition, LA function is linked to both Left Ventricular
      (LV) systolic and diastolic function, manifesting in an overall impact on cardiac remodeling,
      including the area of the pulmonary vein ostia, and a significant decrease in LV ejection
      fraction (LVEF). On the other hand, the positive effects of maintaining sinus rhythm with
      successful catheter ablation of AF may result in improvement of LA mechanical function.5-9

      Based on the potentially deleterious effects of damage caused by cryoablation, to the atrial
      myocardium during balloon ablation, this prospective, non-randomized, single-center study has
      been designed to assess the atrial effects of balloon cryo-ablation.
    

Detailed description: 
      This study is a prospective, non-randomized, single-center, controlled study of patients with
      AF referred for ablation after failing one or more Class I-IV antiarrhythmic drugs used in
      the treatment of AF.

      • All study subjects will undergo cryoablation.

      Subjects will be followed for 12 months to assess the chronic impact of ablation with the
      Medtronic CryoCath Arctic Front™ Cardiac CryoAblation Catheter System on LA and LV mechanical
      function. In addition, patients will undergo scheduled and symptom-driven assessments to
      detect recurrent AF and adverse events (AEs).

      We will evaluate the effect of ablation with the Medtronic Arctic Front™ Cardiac CryoAblation
      Catheter System on the atrial myocardium, with respect to LA (and LV) mechanical function, by
      assessing images acquired using TTE and CT in adult patients with atrial fibrillation who
      have failed at least one anti-arrhythmic drug. The efficacy of the Arctic Front™ Cardiac
      CryoAblation Catheter System will be assessed by ambulatory continuous ECG monitoring
    

Intervention name(s): Pulmonary vein isolation with cryoballoon catheter
Intervention type(s): Device
Intervention description(s): For each patient, the balloon catheter will be advanced to the ostium of each pulmonary vein. Once location has been optimized, the balloon will be inflated, and cryoenergy delivery will be initiated. Because the entire surface of the balloon acts as an ablative surface, circumferential ablation of each pulmonary vein will be achieved concurrently. This will be completed for each pulmonary vein for each patient.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: cryoablation; recurring arrhythmia; stroke; RF ablation; LA ablation; nodal ablation; catheter ablation