1 Cardiovascular Division, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
2 Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
3 Division of Cardiology, Johns Hopkins Hospital, Baltimore, Maryland.
4 Division of Cardiology, University of California San Francisco, San Francisco, California.
5 Cardiovascular Division, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania. Electronic address: David.Frankel@pennmedicine.upenn.edu.