1 Division of Cardiovascular Medicine and Cardiovascular Institute, Stanford University School of Medicine, Stanford, California, USA; Veterans Affairs Palo Alto Healthcare System, Palo Alto, California, USA.
2 Cardiology Section, Medical Service, San Francisco Veterans Affairs Health Care System, San Francisco, California, USA; Department of Medicine, University of California, San Francisco School of Medicine, San Francisco, California, USA; Philip R. Lee Institute for Health Policy Studies, University of California, San Francisco, California, USA. Electronic address: [email protected].