Frank A Lederle1, Janet T Powell2, Christoph A Nienaber3. 1. Center for Chronic Disease Outcomes Research, VA Health Care System (111-O), Minneapolis, MN 55417, USA frank.lederle@va.gov. 2. Vascular Surgery Research Group, Imperial College, London W6 8RP, UK. 3. Heart Center Rostock, University of Rostock, 18055 Rostock, Germany.