Immature Granulocyte Count at Admission Predicts 30-Day Mortality Better Than Troponin in STEMI

Researchers used spectral flow cytometry on admission blood from patients with STEMI, non-STEMI, heart failure, and stroke. They quantified neutrophil maturation stages and plasma inflammatory mediators. STEMI triggered the strongest emergency release of preneutrophils; their presence raised 30-day mortality risk more than established scores, remaining significant after multivariable adjustment. The same immature granulocyte signal was weaker in stroke and heart failure, linking release magnitude to ischemic burden. The finding connects emergency myelopoiesis to clinical outcome. Prior neutrophil studies focused on mature cell counts or NETs; this work shows the bone-marrow reserve itself forecasts death within days. Routine hematology analyzers already flag immature granulocytes, yet most MI risk models ignore them, missing a low-cost marker available at first blood draw. Evidence comes from one prospective observational cohort plus retrospective and prospective validations totaling several hundred patients. It cannot prove causation or define therapeutic targets. Next required studies are prospective integration into TIMI/GRACE scores with pre-specified cut-offs and randomized trials testing whether IG-guided triage alters mortality.