Enrollments slowed down significantly, despite several attempts to re-launch.

Prospective randomized interventional trial comparing the efficacy of circumferential pulmonary vein ostia ablation using surgical versus catheter techniques in the treatment of paroxysmal atrial fibrillation. Success rate determined by REVEAL-XT (AF implantable monitoring device).

Title: Surgical or Catheter Ablation in patients with Lone Atrial Fibrillation: determination of acute and long term SUCCESS (SCALAF-success trial).

Background: Anti-arrhythmic drugs are used in daily practice to treat patients with paroxysmal idiopatic AF. Often the origin of the AF can be found in the muscle sleeves running up the pulmonary veins. Drug treatment is not always successful and prone to evoke negative side effects. The surgical MAZE procedure was applied in the past, but this is a time consuming, cumbersome technique, often associated with significant complications. Cardiac radio-frequency ablation offers an alternative, easy and less time consuming treatment: lesions prevent normal electrical wave front propagation and might stop the continuation of atrial fibrillation wave fronts. Ablation can be implemented by use of special catheters inserted via the groin or using the Medtronic Cardioblate® Surgical Ablation System applied via minimal invasive surgical techniques.

Purpose: Compare the effectiveness of pulmonary vein isolation achieved via catheter or via surgical ablation techniques to treat patients with paroxysmal lone AF.

Study design: A prospective, randomized multi-center interventional study.

Patients: Patients suffering from paroxysmal idiopatic AF (no associated or underlying structural heart disease) complying with following inclusion criteria:

• minimally one documented AF-episode in the last 6 months;
• refractory to at least 2 class I or III anti-arrhythmic drugs;
• age > 18 year

Intervention: Patients are randomized to either the surgical or the catheter ablation group and receive the indicated treatment. During the critical assessment period, the patients are weaned from anti-arrhythmic medication.

Primary endpoint: Reduction in AF occurrence measured by the AF-burden parameter in the critical period between 3 and 6 months post-ablation. AF burden is measured automatically by means of the Reveal XT, implanted at study enrolment to document the baseline characteristics.

Secondary endpoints:

• Failure of therapy requiring re-interventions;
• Duration, burden and costs of ablation procedures:
• Reduction in frequency, duration and level of severity of AF symptoms;
• Occurences of treatments of arrythmic episodes;
• Assessment of AF burden during follow-up period
• Symptoms associated with AF;
• Reduced necessity of anti-arrhythmic or anticoagulant medication;
• Left atrial dimensions and contractility
• Adverse events associated with the ablation therapy;
• Occurrence of other clinical adverse events (TIA, CVA, bleeds, tamponade, MI) at 3, 6, 12 and 24 months of follow up
• Mortality and hospitalisation

Risk assessment: Possible side effects : irregular heart rhythm, pericardial fluid, stroke, heart infarct, disturbances of the conduction system in the heart, local pain at the site of incisions, heart failure or reduced pump function of the heart.

Possible benefits: Regulation of the heart rhythm without applying MAZE procedure or opening of the thorax. Reduction or relief from symptoms associated with AF. Partial or complete reduction of anti-arrhythmic medication. Control of anti-coagulant medication. Improved quality of life for the patients.

Visits are planned at study entrance and Reveal XT implant (assessment at baseline, application of the ablation therapy), discharge from hospital, and at 3, 6, 12 and 24 months post-ablation.

Inclusion Criteria:

• Patient has documented Paroxysmal AF as defined by the ACC/AHA/ESC guidelines
• Minimal one documented AF episode in the last 6 months
• Refractory to minimal two Class I or III anti-arrhythmic drug
• Age > 18 years
• Signed and dated the Patient Informed Consent.
• Patient can tolerate anti-coagulation therapy (Warfarin/Coumadin)

Exclusion Criteria:

• Patient has a structural heart disease
• Ejection fraction < 40 %
• Echocardiographic evidence for a left atrium > 45 mm (parasternal axis)
• Patients on amiodarone, or patients known to be intolerant for amiodarone
• Dextrocardia, current endocarditis, systemic infection, renal failure
• Patient has known cerebrovascular disease, including a history of stroke, CVA or TIA
• Pregnancy at enrolment; or planned pregnancy within the follow up period
• Patient has a life expectancy less than 1 year
• The subject is participating in another device or drug study
• The patient is unable and/or unwilling to cooperate with study procedures or required follow up visits
• Echocardiographic (TTE) evidence for presence of left atrial thrombus
• Previous (cardio-) thoracic surgery
• Previous left atrial ablation
• Patients with permanent or persistent AF

There is no plan or intention to share individual participant data (IPD)

6 months

Adverse Events were monitored for a limited timeframe, ie.up to 6 Months Post-Ablation, by Randomization Group

The study stopped early, prior to meeting the target number of subjects per group. The reported results and conclusions are based on these limited data.