Catheter ablation for atrial fibrillation after an unsuccessful surgical ablation and biological prosthetic mitral valve replacement: a pilot study.

Background: Patients with mitral valve (MV) disease and atrial fibrillation (AF) undergo simultaneous prosthetic valve replacement and radiofrequency (RF) ablation procedure; however, this combinational procedure restores sinus rhythm (SR) in only 68-82% of the cases. In patients with ineffective surgical ablation, the use of a biological prosthetic valve might not only be a good choice to perform safe catheter ablation procedure in the left atrium (LA), but also provide a way to discontinue administration of oral anticoagulants. The objective of this study was to assess the efficacy of catheter ablation for AF after MV replacement with a biological prosthesis and an ineffective surgical ablation procedure.

Methods: Ten consecutive patients aged 48 ± 7 years were enrolled in this study. All patients had long-persistent AF associated with a rheumatic valve disease, which was treated by MV replacement with a biological prosthesis and a surgical RF ablation procedure. In the late postoperative period, all the patients had recurrent hemodynamically significant AF, which required repeated cardioversions. From 1 year to 3 years after the surgery, catheter ablation was performed, including reisolation of pulmonary veins (PVs) with the ablation of ganglionic plexi or linear lesions on the roof of the LA and mitral isthmus. The efficacy was assessed at 3 months, 6 months, and 12 months after the procedure.

Results: Restoration of SR during ablation was achieved in all of the cases. In 6-9 months, all the patients were free of arrhythmia. LA stunning manifested by the absence or decrease of the "A" wave in the transmitral flow and the retrograde wave in the PV flow was observed in nine patients with SR. In five of the patients, LA contractile function was restored in 1-6 months. Prosthetic valve dysfunction was not detected in any of the patients.

Conclusion: Catheter ablation is an effective method for AF treatment following an ineffective surgical RF ablation procedure and biological prosthetic MV replacement. The use of bioprosthetic MVs allows for performing safe catheter ablation without subsequent prosthetic dysfunction.