Long-Term Outcomes of Mechanical Valve Replacement in Patients With Atrial Fibrillation: Impact of the Maze Procedure
What are the benefits of a concomitant Maze procedure in patients with atrial fibrillation (AF) undergoing mitral or aortic valve replacement?
This was a retrospective review of 559 patients (mean age 52 years) with AF (longstanding persistent in 69%) who underwent mitral or aortic valve replacement. At the surgeon’s discretion, 317 patients also underwent a Maze procedure (cryoablation in 317 patients and microwave ablation in 32). Serial electrocardiograms and Holter monitors were obtained to look for recurrent AF during a median follow-up of 63.6 months. The primary outcomes were death and thromboembolism.
Operative mortality was 1.2%, with no significant difference between the two groups. Freedom from AF was significantly greater in the Maze group than in the control group (82% vs. 22% at 3 years, off antiarrhythmic drugs). The overall mortality rate during follow-up was 9.7%, with no significant difference between the Maze and control groups. The thromboembolism rate was 4.0%, with the Maze group having a 71% lower risk of thromboembolism. The lower thromboembolism rate was limited to patients at low-medium operative risk. Echocardiography demonstrated higher ejection fractions and smaller left ventricular and atrial dimensions during follow-up in the Maze group.
In patients with AF undergoing mechanical valve replacement who are at low-medium surgical risk, a concomitant Maze procedure lowers the risk of thromboembolic complications during follow-up.
The results indicate that a lower risk of thromboembolic events when a concomitant Maze is performed during valve replacement does not translate to improved survival. Furthermore, major outcomes are not improved in high-risk patients, suggesting that a Maze is appropriate only for relief of symptoms in such patients.
Keywords: Atrial Fibrillation, Mitral Valve, Echocardiography
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