1. From the Department of Surgery and Cancer, Imperial College London, London, United Kingdom (O.A.J., C.P., A.D., T.A.); Department of Cardiothoracic Surgery, St. Thomas’ Hospital, London, United Kingdom (K.B.); Department of Cardiothoracic Surgery, St Bartholomew’s Hospital, London, United Kingdom (R.U.); and Department of Cardiothoracic Surgery, John Radcliffe Hospital, Oxford, United Kingdom (D.P.T., S.W.).