1. From the Division of Cardiovascular Medicine (K.K.K.) and Quantitative Sciences Unit (B.A.G.), Department of Medicine, Stanford University School of Medicine, Palo Alto, CA; Graduate School of Nursing, Midwifery, and Health, Victoria University of Wellington, New Zealand (R.M.); California Transplant Donor Network, Oakland, CA (J.N.); and Kaiser Northern California Division of Research, Oakland, CA (J.G.Z.).