1 Division of Cardiovascular Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA; The Cardiovascular Quality, Outcomes, and Evaluative Research Center, University of Pennsylvania, Philadelphia, PA; Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia, PA. Electronic address: sri@pennmedicine.upenn.edu.
2 Division of Cardiovascular Medicine, Maine Medical Center, Portland, ME.
3 Division of Cardiovascular Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA; The Cardiovascular Quality, Outcomes, and Evaluative Research Center, University of Pennsylvania, Philadelphia, PA; Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia, PA.