1 Department of Cardiovascular Medicine, MercyOne Iowa Heart Center, Des Moines, Iowa.
2 Department of Cardiovascular Medicine, University of Nebraska Medical Center, Omaha, Nebraska. Electronic address: [email protected].
3 Department of Medicine, East Carolina University, Greenville, North Carolina.
4 Department of Medicine, McLaren Flint-Michigan State University, Flint, Michigan.
5 Department of Cardiovascular Medicine, University of Nebraska Medical Center, Omaha, Nebraska; Department of Cardiovascular Medicine, Baystate Medical Center, Springfield, Massachusetts.