From the Division of Cardiovascular Medicine (L.V.K., E.K.O., C.A.) and Acute Vascular Imaging Centre (C.A.), Radcliffe Department of Medicine, Level 6, West Wing, University of Oxford, Oxford OX3 9DU, England; and Department of Internal Medicine, School of Medicine, Yale University, New Haven, Conn (E.K.O.). (At 2021-02-01)