Efficacy of an additional MAZE procedure using cooled-tip radiofrequency ablation in patients with chronic atrial fibrillation and mitral valve disease. A randomized, prospective trial

AIMS: This study is the first prospective randomized trial evaluating the efficacy of an antiarrhythmic surgical procedure in patients with chronic atrial fibrillation undergoing mitral valve replacement. METHODS AND RESULTS: Thirty consecutive patients with chronic atrial fibrillation undergoing mitral valve replacement were randomized for an additional modified MAZE-operation using intra-operatively cooled-tip radiofrequency ablation (group A) or mitral valve replacement alone (group B). Biatrial contraction was studied and functional capacity was evaluated in spiro-ergometry 6 months after surgery. Thirty-day mortality was 0% in both groups. After 12 months, sinus rhythm was reinstituted significantly more often in patients of group A (cumulative rate of sinus rhythm 0.800) compared to patients in group B (0.267) (P<0.01). 66.7% of patients in sinus rhythm of group A had documented biatrial contraction. Electrocardioversion showed long-term success in only 17% of patients in group A and 0% in group B. Maximal aerobic uptake at the 6-month spiro-ergometry revealed no significant difference (9.3 vs 8.5 ml x min(-1) kg(-1), P=0.530). CONCLUSIONS: A modified MAZE operation using cooled-tip radiofrequency ablation can be safely combined with mitral valve surgery and is highly effective in restoring sinus rhythm. Biatrial contraction is found in 66.7% of patients with sinus rhythm undergoing mitral valve replacement plus the MAZE operation.