Clonal Hematopoiesis of Indeterminate Potential Is Associated With Incident Abdominal Aortic Aneurysm

Clonal hematopoiesis of indeterminate potential (CHIP) is an emerging risk factor for cardiovascular diseases. Genetic IL (interleukin)-6 signaling deficiency reduced cardiovascular disease risk in CHIP carriers. However, the association between CHIP and incident abdominal aortic aneurysm (AAA) and whether IL-6 signaling inhibition attenuates AAA risk among individuals with CHIP remained unclear.

Participants without prevalent AAA from the UK Biobank were included. The associations of any CHIP (variant allele fraction, ≥2%), large CHIP (variant allele fraction, ≥10%), and gene-specific CHIP subtypes with incident AAA were investigated. The protection role of IL6R p.Asp358Ala, a genetic proxy for IL-6 deficiency, was tested after stratification by CHIP status. Furthermore, the interaction and joint effects of CHIP and genetic susceptibility on AAA risk were tested.

This study included 425 211 participants. Any CHIP and large CHIP was identified in 13 768 (3.2%) and 8576 (2.0%) participants, respectively. CHIP was associated with an increased risk of incident AAA (hazard ratio [HR], 1.21 [95% CI, 1.01-1.44]; P=0.034), with large CHIP clones exhibiting greater effect size (HR, 1.35 [95% CI, 1.10-1.66]; P=0.0045). Driver gene-specific analyses revealed that ASXL1-mediated CHIP exerted the strongest effect size on AAA risk (HR, 2.10 [95% CI, 1.54-2.88]; P<0.001). The presence of 2 IL6R p.Asp358Ala alleles attenuated the risk of AAA in large CHIP carriers (HR, 0.48 [95% CI, 0.23-0.99]; P=0.046). In the joint analysis, participants with CHIP and high genetic risk had a higher risk of developing AAA than those without CHIP and with low genetic risk (HR, 2.15 [95% CI, 1.63-2.85]; P<0.001).

CHIP is associated with an increased risk of AAA. Genetic IL-6 signaling deficiency attenuates the risk of AAA in large CHIP carriers. CHIP may serve as an attractive target for the prevention and treatment of AAA.