Left ventricular function and exercise capacity after arterial switch operation for transposition of the great arteries: a systematic review and meta-analysis.

Background: The arterial switch operation for transposition of the great arteries was initially believed to be an anatomical correction. Recent evidence shows reduced exercise capacity and left ventricular function in varying degrees in the long term after an arterial switch operation. Objective: To perform a meta-analysis on long-term exercise capacity and left ventricular ejection fraction after an arterial switch operation. Methods: A literature search was performed to cover all studies on patients who had undergone a minimum of 6 years of follow-up that reported either left ventricular ejection fraction, peak oxygen uptake, peak workload, and/or peak heart rate. A meta-analysis was performed if more than three studies reported the outcome of interest. Results: A total of 21 studies reported on the outcomes of interest. Oxygen uptake was consistently lower in patients who had undergone an arterial switch operation compared with healthy controls, with a pooled average peak oxygen uptake of 87.52.9% of predicted. The peak heart rate was also lower compared with that of controls, at 92 +/- 2% of predicted. Peak workload was significantly reduced in two studies. Pooled left ventricular ejection fraction was normal at 60.7 +/- 7.2%. Conclusion: Exercise capacity is reduced and left ventricular ejection fraction is preserved in the long term after an arterial switch operation for transposition of the great arteries.