Increased mROS Generation Associates With Cardiovascular Risk in BioHEART-CT PBMCs

Coronary artery disease (CAD) remains a leading cause of morbidity and mortality worldwide, and identifying accessible blood-based biomarkers is therefore a clinical priority. Given the involvement of oxidative stress and immune cell dysfunction in atherosclerosis, we investigated whether mitochondrial reactive oxygen species (mROS) production in peripheral blood mononuclear cells (PBMCs) is associated with CAD. This exploratory study analyzed PBMCs from 40 BioHEART-CT participants with or without CT-defined CAD using MitoSOX-based flow cytometry. In parallel, single-cell RNA sequencing (scRNA-seq) was conducted in the same individuals to investigate differential expression of CCBE1, a recently implicated gene in cardiovascular disease, across PBMC populations. Overall, mROS levels in PBMCs and their major cellular subtypes did not show consistent or meaningful associations with CAD status or with modifiable cardiovascular risk factors. Small, subgroup-specific signals-such as moderate association between lymphocyte mROS and coronary artery calcium score in males, and a modest inverse association between monocyte mROS and hypertension-were exploratory and not uniform across analyses. scRNA-seq analysis did not identify a distinct CCBE1 expression signature in PBMCs. These findings indicate that PBMC-derived mROS is unlikely to serve as a useful cross-sectional biomarker of CAD in stable populations.