Paroxysmal Atrial Fibrillation. Clinical Trial
Official title:
Atrial Fibrillation: Ablation or Surgical Treatment II: FAST II A Randomized Study Comparing Non-pharmacologic Therapy in Patients With Drug-refractory Atrial Fibrillation Referred for a First Time Invasive Treatment.
The purpose of this study is to compare two invasive treatments of symptomatic paroxysmal
atrial fibrillation: Percutaneous radiofrequency catheter ablation and mini invasive
thoracoscopic radiofrequency ablation in patients referred for a first time invasive
treatment for atrial fibrillation.
The hypothesis is, that mini invasive thoracoscopic radiofrequency ablation as a first time
invasive treatment is more effective compared to a percutaneous catheter based technique in
patients with symptomatic paroxysmal atrial fibrillation refractory or intolerant to at
least one antiarrhythmic drug.
Atrial fibrillation is characterized by disorganized, rapid, and irregular contraction of
the atria. Its effects on hemodynamic and thromboembolic events result in significant
morbidity, mortality, impaired quality of life, hospitalizations, and health-cost.
It is the most common sustained cardiac arrhythmia. Over six million Europeans suffer from
this arrhythmia. The prevalence is estimated to at least double in the next 50 years and is
probably underestimated due to asymptomatic atrial fibrillation. The prevalence increases
with age and affects men more often.
Atrial fibrillation is treated medically with varying results and there are no definitive
long term curative treatments. The main goal aims at reducing symptoms and preventing
disabling complications. Treatment normally includes antithrombotic, rhythm, and/or rate
management, New non-pharmacological interventions have evolved over the last decades in
order to prevent paroxysmal atrial fibrillation and/or reduce symptoms. The main focus of
non-pharmacological intervention has been on percutaneous radiofrequency catheter ablation
and surgical maze ablation. Both approaches aim at minimizing the impact of "triggers" from
the pulmonary veins by electrical isolation of the veins.
Studies comparing antiarrhythmic drug and radiofrequency ablation indicate that
radiofrequency ablation has a higher efficacy rate, a lower rate of complications, and in
selected patients radiofrequency ablation reduced the risk of atrial fibrillation recurrence
after one year by 65 % compared with antiarrhythmic drug. In a recently published paper the
success rate after a mean of 1.3 radiofrequency ablation procedures per patient varied from
57.7% to 75.4% with higher success rates in patients with paroxysmal atrial fibrillation as
compared to persistent/permanent atrial fibrillation.
European Society of Cardiology recommends that radiofrequency ablation is reserved for
patients who remain symptomatic despite optimal therapy and failed at least one
antiarrhythmic drug.
Dr. James Cox introduced the Cox-maze surgical operation for atrial fibrillation in 1987,
later modified to Cox-maze III also known as the "cut and sew" maze. It is highly successful
in restoring sinus rhythm, with 90-96 % being free from atrial fibrillation at a mean
follow-up of 5.4 years. Due to its complexity and technical difficulty the procedure has not
been widely adopted. Mini invasive procedures for pulmonary vein isolation have been
developed and can now be performed either through mini thoracotomies or using totally
thoracoscopic approach. These procedures also hold the advantage of left atrial appendage
excision or exclusion. The thoracoscopic maze ablation has shown promising results in small
studies in patients with recurrence of atrial fibrillation after earlier catheter based
radiofrequency ablation, after a mean follow-up of 11 months 84 % of the patients remain in
sinus rhythm. However long-term results are still unknown. The procedure still needs to be
compared head to head with catheter based radiofrequency ablation before it should be
offered as a standard treatment of atrial fibrillation.
The rationale for eliminating atrial fibrillation with radiofrequency ablation include a
potential improvement in quality of life, decreased stroke risk, decreased heart failure
risk and improved survival.
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Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Outcomes Assessor), Primary Purpose: Treatment