Clonal Hematopoiesis and Its Cardiovascular Implications: A Scientific Statement From the American Heart Association

Abstract

Clonal hematopoiesis (CH), the benign clonal expansion of hematopoietic stem cells, is often caused by somatic sequence variations in genes associated with hematologic malignancies. Over the past decade, CH has emerged as a risk factor for a wide range of cardiovascular diseases (CVDs), including atherosclerosis, heart failure, atrial fibrillation, and thrombosis. The cardiovascular risk associated with CH is heterogeneous; it varies on the basis of specific genes and variants, clone size, and various extrinsic features. Mechanistic studies suggest that CH contributes to CVDs through both gene-specific pathways and broader inflammatory processes. These include aberrant cytokine production, inflammasome activation, and other proinflammatory mechanisms, which can accelerate atherosclerosis, promote thrombogenesis, and impair vascular or myocardial function. These findings underscore the importance of addressing CH as a potential contributor to CVDs. CH is predominantly considered an age-related phenomenon, but lifelong influences on the fitness of genetic variants, including germline predispositions, obesity, chronic inflammation, and exposure to environmental toxins (eg, tobacco, certain cancer treatments), influence CH. A greater understanding of CH risk factors is therefore important for both individual and population-level risk assessments. Incorporating CH-associated risk into existing CVD risk prediction models may inform new personalized preventive or therapeutic approaches. No CH-specific therapies have proven efficacy in CVD treatment or prevention, but multiple molecular-based therapeutic hypotheses are beginning to be tested.