Abstract Background Clonal hematopoiesis of indeterminate potential (CHIP) is an acquired, genetic cardiovascular (CV) risk factor affecting about 10% of the general population at the age of 70 years. Experimental studies suggest a causal link between CHIP and inflammation-driven atherosclerosis. We hypothesized that CHIP is more frequent in patients undergoing coronary angiography and associates with coronary artery disease (CAD) severity. Methods Patients at the age of 40 or older, presenting indications for a left heart coronary angiography examination at the Freiburg Heart Center, Germany, were eligible for screening. Study participants presenting abnormal hematological readouts, C-reactive protein >10 mg/L, glomerular filtration rate <30 mL/min/m2, undergoing antibiotics treatments, having history of malignancy or chronic inflammatory diseases were excluded. Genomic DNA (gDNA) extracted from citrated arterial blood, sampled during angiography, was subjected to CHIP-driver gene mutation screening (TruSight Myeloid Sequencing Panel, Illumina). Targeted genomic sequencing. CAD severity was determined in coronary angiograms using Gensini score by investigators blinded to DNA sequencing results. Results We enrolled 178 out of 815 patients that were screened for our observational study, which did not feature exclusion criteria such as hematologic abnormalities or relevant comorbidities (see methods). Median age was 69 years. With a cutoff of 2% variant allele frequency (VAF), nearly 30% of the included patients carried CHIP driver mutations – a prevalence at least three times higher compared to the general public. Most CHIP carriers harbored only one mutation, nearly 80% of mutations were located in the epigenetic regulator genes, DNMT3A and TET2. Among the included patients, the clinical characteristics were generally comparable between the CHIP-carriers and the non-carriers in terms of gender, body mass index, differential blood count, C-reactive protein, lipid profiles, and CV comorbidities. As expected, CHIP-carriers were significantly older. Approximately 80% of patients in our cohort were diagnosed with CAD, the severity of which was quantified by Gensini score, accounting for both the degree and location of coronary artery plaque stenosis. Overall, CHIP-carriers presented with higher scores. in the middle-aged population (40-69 years old) harboring DNMT3A or TET2 mutations, Gensini scores were twice as high compared to non-carriers. Conclusion Our findings support a role of CHIP as a novel acquired cardiovascular risk factor independent of other modifiable risk factors, in particular in the middle-aged population that is more affected by genetic traits. CHIP carrier status is disproportionally high among patients in the catherization laboratory and may represent a population to consider additional anti-inflammatory therapy.
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