1. From the Stroke Prevention Research Unit, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, United Kingdom (S.T.P., P.-J.C., L.B., L.S., Z.M., P.M.R.); and University of Oxford, United Kingdom (S.T.P., P.-J.C., L.B., L.S., Z.M., P.M.R.).