CD40 and congestive heart failure: These relative abundances showed the following positive correlations with established preoperative risk factors of POD: age correlated with abundance of CD40+ classical monocytes; EuroSCORE II, with abundances of CD69+CD8+ T cells, CD279+CD4+ TEMRA, and HLA-DR+ classical monocytes; congestive heart failure, with abundances of CD69+CD8+ T cells, CD279+CD4+ TEMRA, and CD40+/HLA-DR+ classical monocytes; and use of positive inotropic drugs, with abundances of CD279+CD4+ TEMRA and HLA-DR+ classical monocytes.