Aims: Transposition of the great arteries (TGA) is generally repaired using the arterial switch operation (ASO) involving coronary transfer. The objective of this prospective study was to determine whether specific coronary Doppler patterns intra-operatively predicted adverse early myocardial events.
Methods and results: Patients < 3 months old with TGA undergoing the ASO were eligible. All patients (when feasible) underwent an intra-operative transoesophageal echo (TEE) plus an epicardial echo and had pre-op, early post-op, pre-discharge and follow-up functional echocardiograms. The primary endpoint was a composite myocardial ischaemic event (any of: post-operative ST changes, ventricular tachycardia, need for extracorporeal membrane oxygenation (ECMO). Associations of coronary Doppler flow patterns with outcomes were modelled with logistic regression models. From May 2009 to December 2012, 40 patients (29 male, birth weight 3.29 ± 0.58 kg) were recruited. n = 32 had TEE + epicardial, four TEE only, four epicardial only. Seven (18%) patients had an adverse myocardial event (five ST changes, two ventricular tachycardia (one also ECMO). There was one death. n = 3 had a coronary artery (CA) revision post-operatively, and three had re-operation for non-CA causes. By TEE, flow reversal in the left coronary artery was associated with the composite endpoint [Odds Ratio (OR) 31.5, P = 0.004], and for chest open > 3 days (OR 6.67, P = 0.0537). Coronary Doppler flow patterns were similar by TEE and epicardial echo. The tissue Doppler parameters showed an early post-op decrease (P < 0.001 for all measures), with full recovery at follow-up in 31/37 cases.
Conclusion: Intra-operative evaluation of coronary artery flow patterns should be considered for patients undergoing the ASO.