Somatic mutation contributing to clonal haematopoiesis is a risk factor of recurrent stroke in first-ever acute ischaemic stroke: a prospective cohort study

Background Somatic mutation contributes to clonal haematopoiesis of indeterminate potential (CHIP) is related to age and associated with a higher risk of stroke and atherosclerotic cardiovascular disease. Here, we investigated the prognostic significance of CHIP in a large first-ever acute ischaemic stroke (AIS) cohort and explored the underlying mechanisms. Methods We studied a prospective cohort of 6016 patients who had a first-ever AIS in China. Whole-genome sequencing was performed to identify CHIP. High-sensitivity C reactive protein (hs-CRP) levels above 3 mg/L at baseline were defined as hyperinflammation. Recurrent stroke during the 3-month follow-up was the primary outcome. Results Among the 6016 patients who had a first-ever AIS, with a median age was 62 years (IQR, 54.0-70.0), 3.70% were identified as CHIP carriers. The most common mutations occurred in the DNMT3A (30.0%) and TET2 (11.4%) genes. During a follow-up of 3 months, the presence of CHIP was associated with recurrent stroke (HR 1.62, 95% CI 1.04 to 2.51, p=0.03), recurrent ischaemic stroke (HR 1.64, 95% CI 1.04 to 2.58, p=0.03) and combined vascular events (HR 1.58, 95% CI 1.02 to 2.44, p=0.04) after adjusting for hsCRP levels at baseline in patients who had a first-ever AIS. Subgroup analysis demonstrated that CHIP was only associated with recurrent stroke when patients under hyperinflammation (OR 3.10, 95% CI 1.92 to 5.00, p<0.001) but not in those without hyperinflammation (OR 0.18, 95% CI 0.03 to 1.04, p=0.06, P-interaction=0.002). Conclusion Our results suggest that somatic mutations contributing to CHIP increase the risk of short-term recurrent stroke in patients who had a first-ever AIS. Hyperinflammation may be important in the relationship between CHIP and recurrent stroke.

Automated summary

The presence of somatic mutations contributing to clonal haematopoiesis of indeterminate potential (CHIP) is associated with a higher risk of recurrent stroke, recurrent ischaemic stroke, and combined vascular events in patients who had their first-ever acute ischaemic stroke. Hyperinflammation may play an important role in the relationship between CHIP and recurrent stroke.