Biomarkers of brain injury after cardiac arrest; a statistical analysis plan from the TTM2 trial biobank investigators by Moseby-Knappe, M, Levin, H, Blennow, K, Ullén, S, Zetterberg, H, Lilja, G, Dankiewicz, J, Jakobsen, JC, Lagebrant, A, Friberg, H, Nichol, A, Ainschough, K, Eastwood, GM, Wise, MP, Thomas, M, Keeble, T, Cariou, A, Leithner, C, Rylander, C, Düring, J, Bělohlávek, J, Grejs, A, Borgquist, O, Undén, J, Simon, M, Rolny, V, Piehler, A, Cronberg, T, Nielsen, N