Atrial fibrillation (AF) is the most common cardiac arrhythmia with a lifetime risk of developing AF of 1 in 4 people aged over 40. Besides hemodynamic compromises stroke remains the most feared complication of AF with an increase in risk by 5-fold.

Catheter ablation has evolved as a standardized treatment option in paroxysmal AF. Due to the advanced electrical and structural remodeling the single procedural results of catheter ablation for persistent and longstanding persistent AF are rather disappointing without a proven superiority of any applied strategy compared to others. However, repeated catheter ablation can achieve better results. The surgical (epicardial) approach seems to be more effective, though still a significant amount of failures exist. Checking the epicardial ablation lines and if necessary making additional endocardial lines (which is a hybrid ablation) is expected to be most efficacious in avoiding lesion gaps and providing the most complete lesion set.

The study objective of this pilot trial is to compare the safety and efficacy of catheter ablation within 6 months versus a hybrid ablation consisting of endoscopic epicardial surgery combined with endocardial catheter ablation (performed one-stage) in preventing the recurrence of atrial fibrillation (AF) in symptomatic, drug refractory patients with persistent or longstanding persistent atrial fibrillation.

Inclusion Criteria:

• Known with a history of symptomatic persistent AF or longstanding persistent atrial fibrillation,
• Refractory to or intolerant of at least one antiarrhythmic drug class I or III,
• At least 18 years of age,
• Mentally able and willing to give informed consent.

Exclusion Criteria:

• Previous ablation procedure,
• Longstanding persistent AF > 3 years,
• Paroxysmal atrial fibrillation. Successful cardioversion within 48 hours of onset of the arrhythmia will be also considered paroxysmal. In patients with paroxysmal and persistent AF, the dominant pattern should be taken to categorize,
• Atrial fibrillation secondary to electrolyte imbalance, thyroid disease, or other reversible or non-cardiovascular cause,
• Presence of left atrial appendage (LAA) thrombus,
• Left atrial size ≥ 60mm (PLAX-view on TEE),
• Left ventricular ejection fraction < 40%,
• In need for other cardiac surgery then AF treatment within 12 months,
• Intolerance to heparin and warfarin,
• Unable to undergo TEE,
• Sick-sinus-syndrome
• Mitral valve insufficiency > Iº
• Carotic stenosis > 80%,
• Active infection or sepsis,
• Pleural adhesions,
• Elevated hemi diaphragm
• Significant pulmonary dysfunction as assessed by preoperative lung testing,
• Chronic obstructive pulmonary disease with a FEV1 or VC < 50% predicted
• History of cerebrovascular accident (CVA) or transient ischemic attack (TIA),
• History of blood clotting abnormalities,
• History of thoracic radiation,
• History of pericarditis,
• History of cardiac tamponade,
• History of thoracotomy or cardiac surgery,
• Body-mass-index > 40,
• Pregnancy,
• Life expectancy less than 12 months,
• Participation in any other clinical study involving an investigational drug or device.