Atrial Fibrillation catheter Ablation Versus Surgical Ablation Treatment - FAST

Description:

The current trial sought to compare outcomes after catheter-based ablation (pulmonary vein isolation [PVI]) versus a minimally invasive surgical approach in patients with severe symptomatic drug-refractory atrial fibrillation (AF).

Hypothesis:

Minimally invasive surgical ablation would be superior to percutaneous PVI in patients with severe symptomatic drug-refractory AF.

Study Design

  • Randomized
  • Blinded
  • Placebo Controlled
  • Parallel

Patient Populations:

  • Drug-refractory AF, documented in the last 12 months
  • Symptom duration >12 months
  • High chance of catheter-based failure due to:
    • LA diameter >40-44 mm with hypertension
    • LA diameter ≥45 mm
    • Failed prior catheter-based ablation

      Number of enrollees: 129
      Duration of follow-up: 2 years
      Mean patient age: 56 years
      Percentage female: 20%
      Ejection fraction: 56%

Exclusions:

  • AF >1 year
  • Catheter ablation or surgical procedure within 3 months
  • Previous stroke/transient ischemic attack
  • LA size >65 mm
  • Left ventricular ejection fraction <45%
  • Mitral or aortic regurgitation >2+
  • Moderate to severe mitral stenosis or aortic stenosis
  • Active infection or sepsis
  • Unstable angina
  • Myocardial infarction within 3 months
  • AF secondary to electrolyte imbalance
  • Thyroid disease
  • History of blood clotting abnormalities

Primary Endpoints:

  • Efficacy: Freedom of LA arrhythmia lasting >30 seconds, in the absence of AAD
  • Safety: Significant adverse events, both acute and chronic

Secondary Endpoints:

  • Freedom of LA arrhythmia lasting >30 seconds, with AAD use

Drug/Procedures Used:

Eligible patients were randomized to a minimally invasive surgical approach (PVI, ganglionic plexi ablation, and left atrial appendage [LAA] excision) by VATS under GA, or catheter-based PVI with linear antral PVI, guided by 3-D mapping.

Concomitant Medications:

Amiodarone (35%)

Principal Findings:

A total of 129 patients were enrolled at two centers, 61 to surgical approach and 63 to catheter-based PVI. Baseline characteristics were similar between the different arms. The mean LA diameter was 4.3 cm, and approximately 70% had a history of prior failed catheter-based ablation. Approximately 60% had paroxysmal AF, and about 40% had been on three or more antiarrhythmic drugs (ADDs) in the past. The total procedure time was higher in the surgical arm (188 vs. 163 minutes, p = 0.018). Two or more additional LA lines were necessary in about 19% of patients in both arms.

The primary efficacy (freedom from LA arrhythmia lasting >30 seconds, in the absence of AAD) was significantly higher in the surgical arm as compared with the catheter-based arm (65.6% vs. 36.5%, p = 0.0022). On allowing for AAD use, results were similar (42.9% vs. 78.7%, p < 0.0001). Results were also similar in the group that had failed catheter-based ablation before (68.2% vs. 36.8%, p = 0.0089). There were no deaths in either arm; all complications were significantly higher in the surgical arm (23% vs. 3.2%, p = 0.001), including six instances of pneumothorax.

Interpretation:

The results of this trial indicate that a minimally invasive surgical approach involving PVI, ganglionic plexi ablation, and LAA excision was superior to a catheter-based approach involving PVI guided by 3-D mapping in reducing the primary endpoint of freedom from LA arrhythmia lasting >30 seconds in patients with drug-refractory symptomatic AF. The surgical approach was, however, associated with a significant increase in complications, including pneumothorax.

These results are interesting and applicable only to patients with severe refractory AF, most of whom had a prior attempt at catheter-based ablation, but unlikely to change practice soon, since longer studies with harder endpoints are necessary.

References:

Boersma LV, Castella M, van Boven W, et al. Atrial Fibrillation Catheter Ablation Versus Surgical Ablation Treatment (FAST): A 2-Center Randomized Clinical Trial. Circulation 2011;Nov 14:[Epub ahead of print].

Presented by Dr. Lucas Boersma at the American Heart Association Scientific Sessions, Orlando, FL, November 14, 2011.

Clinical Topics: Arrhythmias and Clinical EP, Prevention, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Hypertension

Keywords: Thoracic Surgery, Video-Assisted, Follow-Up Studies, Atrial Appendage, Pulmonary Veins, Pneumothorax, Electrophysiologic Techniques, Cardiac, Catheter Ablation, Hypertension


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