Impact of follow-up on the success rate of the cryosurgical maze procedure in patients with rheumatic heart disease and enlarged atria

Objectives: The most important predictors for failure of the maze procedure are long standing atrial fibrillation (AF), rheumatic heart disease (RHD), and enlarged atria. It is well documented, however, that some patients have recurrence of atrial arrhythmia only late in follow-up. The aims of this study are to assess the effectiveness of the maze procedure and late cardioversion (pharmacologic or electrical) in patients wtih an increased risk for procedure failure. Patients and Methods: Fifty-five patients with AF, enlarged left atrium (>5 cm), and/or RHD were enrolled in the study. Cryosurgery was performed on all patients and was combined with bipolar radiofrequency in the last four patients. The lesion pattern resembles the maze procedure. A follow-up was completed on all patients (24.5 +/- 9.6 months with a range of 3-39 months). Results: The operative mortality was 3.7% (2 patients), both deaths unrelated to the maze procedure. Ninety-eight percent of patients were free of AF upon discharge, with an 11% incidence of early pacemaker implantation. In the first three months postoperatively, 53% of the patients experienced intermittent atrial arrhythmia. Four patients were recorded with permanent AF in late follow-up. The only predictor for late AF (>3 months of follow-up) was perioperative AF. Atrial size, RHD, and AF duration did not predict late failure. Conclusions: The maze procedure can be applied with high success rate in patients with RHD, enlarged atria, and long-standing AF. In our experience many of the late recurrences were recorded late in the follow-up and were treated successfully with antiarrhythmic drugs and/or cardioversion. Therefore a close follow-up is required to enhance the success rate of the procedure.