Immune Aging is an Independent Risk Factor for Cardiovascular Disease.

Cardiovascular disease remains the leading cause of mortality worldwide, yet substantial risk persists beyond traditional clinical and metabolic predictors. The immune system is a key mediator of this residual risk, but clinically scalable metrics of immune state are lacking. Here, we established the clinical and prognostic relevance of IMM-AGE, a system-level metric of immune aging derived from immune cell correlation structure. We developed a transcriptomic gene-ratio signature and optimized reduced-marker flow cytometry panels that accurately preserve IMM-AGE across blood fractions, platforms and cohorts. Applying these clinic-ready implementations across population-based and disease-specific datasets, we show that elevated IMM-AGE is consistently associated with cardiovascular phenotypes and disease. We leverage the UK biobank to show that incorporation of IMM-AGE into the PREVENT 10-year risk equation increase accuracy of risk stratification. We also show that in elderly patients undergoing transcatheter aortic valve replacement, baseline IMM-AGE independently predicted early maladaptive cardiac remodeling and one-year mortality. Finally, in the Baseline Health Study, a large longitudinal cohort, IMM-AGE stratified cardiovascular event risk among individuals with otherwise similar clinical profiles. Together, these findings establish immune aging as a transferable, biologically grounded risk dimension and support IMM-AGE as a practical tool for precision cardiovascular risk assessment.