1. Department of Medicine, Division of Cardiology, University of Washington and King County Emergency Medical Services, Public Health–Seattle & King County, WA (P.J.K., T.R.).
2. Department of Biostatistics, University of Washington Clinical Trial Center, Seattle, WA (B.G.L.).
3. Department of Emergency Medicine, Oregon Health & Science University, Portland (M.D.).
4. Department of Emergency Medicine, Ottawa Hospital Research Institute, University of Ottawa, Canada (C.V., I.G.S.).
5. Rescu, Li Ka Shing Knowledge Institute, St. Michael’s Hospital, University of Toronto, Ontario, Canada (L.J.M., P.D.).
6. University of Pittsburgh, PA (C.W.C.).
7. Department of Emergency Medicine, University of British Columbia Faculty of Medicine, Vancouver, Canada (J.C.).
8. Department of Emergency Medicine, Virginia Commonwealth University Health System, Richmond, VA (J.P.O.).
9. Department of Emergency Medicine, University of California San Diego, San Diego Fire-Rescue Department (J.V.D., G.M.V.).
10. Clark County Emergency Medical Services, Vancouver, WA (L.W.).
11. Johns Hopkins University, Baltimore, MD (M.L.W.).
12. Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee (T.P.A.).
13. Departments of Emergency Medicine and Internal Medicine, University of Texas Southwestern Medical Center, Dallas (A.H.I.).
14. Department of Emergency Medicine and Pediatrics, Medical College of Wisconsin, Milwaukee (M.R.C.).
15. Dallas Fire-Rescue Department, TX (T.K.).
16. National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (D.E., P.D.-N.).
17. University of Alabama, Birmingham (P.G., R.G.).
18. Providence Health and British Columbia Emergency Health Services, Vancouver, Canada (R.S.).