Highlights The atherosclerotic process is caused by phenotypic heterogeneity and cellular plasticity of the immune system and vascular wall. Somatic mutations and clonal hematopoiesis with uncertain potential demonstrate a close association with cardiovascular diseases and acute vascular events. Abstract The last decade of cardiogenetic studies focused on inherited germline mutations. Recently researchers demonstrated a significant role of cellular heterogeneity, somatic mosaicism, and clonal hematopoiesis in the risk of coronary disease and acute vascular disorders. Up-to-date technologies, such as single-cell sequencing and mass cytometry, have made it possible to reveal fundamentally new mechanisms for the development of cardiovascular diseases. This review discloses cutting-edge data on atherosclerosis and vascular disorders, focusing on cellular heterogeneity, somatic mosaicism, and clonal hematopoiesis.