Heart Failure, Congestive

• University of Alabama at Birmingham — Birmingham, Alabama, United States
• Dartmouth-Hitchcock Medical Center, Dartmouth College, Dartmouth-Hitchcock Heart & Vascular Center — Lebanon, New Hampshire, United States

• Ahmanson-UCLA Cardiomyopathy Center — Los Angeles, California, United States

• Ben Taub General Hospital — Houston, Texas, United States

Not specified

• Duke University Medical Center — Durham, North Carolina, United States

• Department of Cardiology, Heart and Diabetes Center North Rhine-Westphalia, Ruhr University Bochum — Bad Oeynhausen, Germany

• The Ohio State University — Columbus, Ohio, United States

• Wake Forest University Baptist Medical Center — Winston-Salem, North Carolina, United States

• GSK Investigational Site — Cambridge, United Kingdom

• University of Wisconsin Hospital and Clinics — Madison, Wisconsin, United States