1. Division of Cardiology, Department of Medicine, Virginia Commonwealth University, Richmond, VA, USA
2. Division of Cardiac Surgery, Department of Surgery, University of Virginia, Charlottesville, VA, USA
3. Virginia Cardiovascular Services Quality Initiative, Falls Church, VA, USA
4. Cardiac Surgery, Inova Fairfax Hospital, Fairfax, Virginia, USA
5. Division of Cardiothoracic Surgery, Department of Surgery, Virginia Commonwealth University, Richmond, VA, USA