The total procedure-related complications after surgical minimally invasive pulmonary vein isolations (MIPI) were higher; this was mainly due to more major complications. During a two-year follow-up there were three transient ischaemic attacks or cerebrovascular accidents after MIPI compared to zero after catheter ablation.
Head-to-head randomised comparison of primary surgical and catheter ablation has not been performed before. Previous randomised studies comparing surgical and catheter ablation of atrial fibrillation (AF) always included patients with unsuccessful previous catheter ablation. The SCALAF (surgical vs. catheter ablation of paroxysmal and early persistent atrial fibrillation) trial compared surgical and catheter ablation of paroxysmal and early persistent AF. The current European Society of Cardiology/ European Heart Rhythm Society (ESC/EHRA) guidelines recommend both percutaneous catheter ablation and surgical ablation in the treatment of symptomatic drug refractory paroxysmal and early persistent AF with different classes and levels of evidence.
This was the first randomised controlled trial that randomised patients without structural heart disease with symptomatic AF to surgical or percutaneous ablation as a first invasive procedure. The follow-up strategy of this study comprised continuous rhythm monitoring with the use of implantable loop recorders in all patients.
Patients with paroxysmal or early persistent AF were randomised, with a 1:1 ratio, to undergo either percutaneous catheter ablation for pulmonary vein isolation without additional lesion sets or surgical pulmonary vein isolation and left atrial appendage. The primary outcome measure was freedom from atrial tachyarrhythmia off antiarrhythmic drugs and the safety endpoint was procedure related complications.
Eighty patients were enrolled on the trial and received an implantable loop recorder (Reveal XT, Medtronic), leading to a total of 52 patients being randomised to the two groups. A total of 25 MIPI patients were analysed as one was lost to follow-up, 25 catheter patients were also analysed as one was excluded due to a left atrial volume index >50ml/m2.
The trial found that MIPI procedures had a higher procedure-related complication-rate after surgery (34.8% vs. 11.1%) and a higher rate of major complications (22% vs. 0%).
Hospitalisation was also longer for patients receiving surgical ablation with an average hospital stay of nine (6–10) days compared to three (2–3) days for catheter ablation.
After two years a significantly greater proportion of patients after percutaneous catheter ablation as compared to surgical pulmonary vein isolation had AF burden <0.5% without the use of antiarrhythmic drugs (60.0% vs. 27.3%, p=0.047).
The investigators concluded that percutaneous isolation of the pulmonary veins in the treatment of paroxysmal and early persistent atrial fibrillation is safer and results in higher long-term arrhythmia free survival compared to surgical pulmonary vein isolation with left atrial appendage ligation. Rhythm follow-up with continuous monitoring using implantable loop recorders is important to obtain the true and accurate outcome of invasive atrial fibrillation treatment.