1 Department of Perioperative Medicine, Barts Heart Centre and St. Bartholomew's Hospital, London, UK; William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary University of London, London, UK; Outcomes Research Consortium, Cleveland, OH.
2 Department of Perioperative Medicine, Barts Heart Centre and St. Bartholomew's Hospital, London, UK; William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary University of London, London, UK.
3 Department of Perioperative Medicine, Barts Heart Centre and St. Bartholomew's Hospital, London, UK; Outcomes Research Consortium, Cleveland, OH; German Heart Center, Berlin, Germany.