Acknowledgements
The Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) National Cardiac Surgery Database Program is funded by the Department of Health, Victoria, the Health Administration Corporation (GMCT) and the Clinical Excellence Commission (CEC), NSW, and funding from individual Units. ANZSCTS Research activities are supported through a National Health and Medical Research Council Senior Research Fellowship and Program Grant awarded to C.M. Reid.