Influence of the maze procedure on the treatment of rheumatic atrial fibrillation - evaluation of rhythm control and clinical outcome in a comparative study

OBJECTIVE: The aim of this study was to evaluate the influence of the maze procedure on the treatment of rheumatic atrial fibrillation in patients with mitral valve disease. METHODS: Fifty-five patients (mean age 51 years; 47 females) with rheumatic mitral valve disease and associated atrial fibrillation in New York Heart Association functional class III or IV, preoperatively, were operated upon. Thirty-five had double dysfunction, 19 had stenosis, and one had mitral regurgitation. None had other associated heart diseases or previous operations. The patients were divided into two groups: GI, 20 patients were treated for mitral valve disease with associated maze procedure; GII, 35 patients were treated for mitral valve disease without the maze procedure. The preoperative echocardiogram showed a left atrial diameter in GI of 5.35 mm and in GII of 5.57 mm (P=0.779). The groups were considered clinically similar (P=0.759). Cardiopulmonary bypass was used in all patients. The mitral valve was replaced with a biological prosthesis in 24 patients and repaired in 31 patients. RESULTS: Three hospital deaths occurred, one in GI, two in GII. After cardiopulmonary bypass, 37.1% of patients in GII remained in atrial fibrillation. All patients in GI recovered regular rhythm (P<0.0001). In the ICU, atrial fibrillation was detected in 80% of patients in GII and maintained in 76.4% in a mean follow-up period of 38.5 months. In GI, atrial fibrillation occurred in 20% of patients in the ICU and maintained in 5.3% in 41 months of mean follow-up (P=0.0001). None of the patients in GI and 20.6% of patients in GII had a thromboembolic episode 1-63 months after the operation (P=0.041). Four late deaths occurred (two in each group), two being due to progression of valvular disease, one after an episode of pulmonary infection and one with no cardiac cause. CONCLUSION: The maze procedure is effective in treating atrial fibrillation in patients with rheumatic mitral valve disease. The results are sustained in the mid-term follow-up period, preventing postoperative thromboembolic episodes, and with acceptable morbidity and mortality.