1 Department of Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
2 Center for Medical Ethics and Health Policy, Baylor College of Medicine, Houston, Texas, USA.
3 Department of Medicine, Michael E DeBakey VA Medical Center, Houston, Texas, USA.
4 Department of Medicine/Division of Cardiology, Department of Bioethics and Humanities, University of Washington School of Medicine, Seattle, Washington, USA [email protected].