Results of the first investigator-initiated randomized clinical trial of nMARQTM, PVACTM, and thoracoscopic ablation for paroxysmal atrial fibrillation

Aims: To investigate the effect of minimally invasive thoracoscopic surgical ablation and nMARQ irrigated multi-electrode phased radiofrequency (RF) ablation to treat paroxysmal atrial fibrillation (AF) compared with PVAC multi-electrode phased RF ablation, with beat-to-beat device-derived Holter monitoring throughout the study duration. Methods and results: An investigator-initiated prospective trial of patients with paroxysmal AF randomized (1:1:1) to initial surgical, nMARQ or PVAC ablation. All patients had continuous beat-to-beat monitoring with an ILR or pacemaker to evaluate and document AF recurrence. There was a strong trend (P = 0.050) toward difference in AF outcome, with surgical AF ablation more efficacious than catheter ablation. At one year, the proportion of patients with less than 1% AF burden after one procedure and off all antiarrhythmic drugs was 63, 56, and 90% for PVAC, nMARQ and surgical ablations respectively. There were significantly more repeat ablations in the catheter ablation groups (P = 0.008): 25% PVAC, 27% nMARQ, 0% surgery. However, 7 of 20 (35%) of patients undergoing surgical ablation suffered a procedural complication, including two sternotomies for bleeding and one death. This was higher than for catheter ablation (P < 0.001). Surgical ablation took longer to perform (P < 0.001) and had a longer hospital admission (P < 0.001) than catheter ablation. Conclusion: Surgical AF ablation required significantly fewer repeat procedures than catheter ablation, and there was a clear trend towards improved arrhythmia outcome. However, it was associated with a significantly higher rate of procedural complications. Surgical ablation for paroxysmal AF is promising, however more prospective outcome data is required. Clinical Trial Registration: NCT01504451, http://clinicaltrials.gov/show/NCT01504451.