1. From the Division of Cardiovascular Diseases (W.M., M.P., A.J.), Department of Medicine, Mayo Clinic, Rochester, MN; Pioneer HiBred International, Inc. (U.S.), Hayward, CA; Division of Biomedical Statistics and Informatics (C.W.), Mayo Clinic, Rochester, MN; Ortho Clinical Diagnostics (A.L., R.P.), Raritan, NJ.