1. Gill Heart and Vascular Institute, Division of Cardiovascular Medicine University of Kentucky Lexington Kentucky USA
2. Department of Biostatistics, College of Public Health University of Kentucky Lexington Kentucky USA
3. Cardiovascular Division, Department of Medicine University of Pennsylvania Perelman School of Medicine Philadelphia Pennsylvania USA
4. Department of Mechanical Engineering, College of Engineering University of Kentucky Lexington Kentucky USA
5. Department of Surgery, College of Medicine University of Kentucky Lexington Kentucky USA