Background: Atrial fibrillation (AF) has been reported to be a predisposing factor for the progression of TR in patients with previous mitral or combined mitral/aortic valve surgery. We hypothesized that the maze operation (MAZE) can prevent the progression of tricuspid regurgitation (TR) in these patients.
Methods and results: We analyzed 170 patients (age, 45.5+/-10.9 years) who had undergone mitral or combined mitral/aortic valve surgery. On the basis of preoperative rhythm, patients were divided into 3 groups; GrI was composed of 44 patients with sinus rhythm, GrII of 48 who had undergone MAZE, and GrIII of 78 with AF who had not undergone MAZE. Echocardiographic examinations were performed before, immediately after, and 92.2+/-17.2 (range, 50 to 131) months after surgery. Preoperative and immediate postoperative clinical and echocardiographic parameters were similar among the groups. Insignificant TR at the immediate postoperative examination worsened with time in 7.3% of GrI (3 of 41), 12.8% of GrII (6 of 47), and 38.8% of GrIII (26 of 67) patients at the final examination (P=0.63 for GrI versus GrII, P=0.001 for GrI versus GrIII, P=0.005 for GrII versus GrIII). The incidence of significant TR at the final echocardiographic examination was higher in GrIII (39.7%) compared with GrI (9.1%) and GrII (14.6%) (P=0.001 for GrI versus GrIII, P=0.005 for GrII versus GrIII), whereas GrI and GrII did not show any difference (P=0.63). By multivariate analysis, the only factor identified to prevent TR progression was the group factor (GrI and GrII versus GrIII, P=0.002 and P=0.005, respectively). In a subgroup analysis of GrII according to the presence or absence of atrial mechanical activity, the absence of atrial mechanical activity was identified as an independent parameter for the progression of TR (P=0.001).
Conclusions: AF predisposes patients undergoing mitral valve surgery to the progression of TR, which can be prevented by MAZE. This additional benefit of MAZE is largely dependent on the restoration and maintenance of atrial mechanical function.