Abstract 12959: Clonal Hematopoiesis of Indeterminate Potential Predicts Incident Venous Thromboembolism in the UK Biobank Cohort

Abstract

Introduction: Clonal hematopoiesis of indeterminate potential (CHIP) refers to the formation of genetically distinct subpopulations of blood cells due to somatic mutations. CHIP is associated with a variety of adverse outcomes, including hematological cancers, cardiovascular disease, and death. We sought to investigate the association of CHIP with incident venous thromboembolism (VTE). Methods: We analyzed exome sequence data from 200,628 individuals in the UK Biobank cohort using Mutect2 to identify a prespecified list of somatic mutations in DNMT3A, TET2, and ASXL1, which are known genetic drivers of CHIP. CHIP was defined as harboring a somatic mutation at a variant allele fraction (VAF) ≥10% and individuals with VAF <2% were deemed as non-carriers. VTE was ascertained using verbal interview data and diagnostic/procedural codes and defined as a composite of the following: thrombophlebitis of deep veins of lower limbs, embolism/thrombosis of vena cava, pulmonary embolism, venous thrombectomy of lower limb veins or IVC filter insertion. We implemented a nested case-control design with incidence density sampling to identify incident cases and controls matched (1:8 ratio) for sex, smoking status, and history of malignancy at baseline. Conditional logistic regression analysis adjusted for age, BMI, and genetic ancestry was performed to assess the association between CHIP and incident VTE. Results: Among 200,628 individuals, we identified 3,885 individuals with CHIP at baseline and 748 incident VTE events during a median follow-up of 9.2 years. In 748 incident cases and 5984 matched controls, CHIP was associated with increased risk of incident VTE independent of conventional risk factors for VTE, namely, age, sex, BMI, smoking, and history of malignancy (incidence rate ratio [95% confidence interval]; 1.60 [1.04-2.46], p=0.032). When we restricted the cases to individuals with incident pulmonary embolism (n=441), we observed a stronger association with CHIP (1.80 [1.08-3.05], p=0.025). Conclusions: CHIP is associated with increased risk of VTE independent of history of malignancy and other conventional risk factors. The pathophysiological basis for this association needs further investigation.