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