CAD patients had lower numbers of naïve CD4 and CD8 T cells, higher proliferation of T regulatory cells and B cells, higher numbers of differentiated conventional and regulatory CD4 T cells and increased terminally differentiated CD4 and CD8 T cells with the cytotoxic KLRG1+CD27‐ phenotype, which we demonstrate improves the predictive ability of atherosclerotic risk models. Here, KLRG1 is linked to coronary artery disorder.