Iron Deficiency in Acute Coronary Syndromes-Clinical Correlates and Outcomes

Iron deficiency is common in heart failure and relates to a worse prognosis, but its role in acute coronary syndromes is unclear. This study assessed iron deficiency prevalence, correlation with infarct size and left ventricular function, and association with in-hospital and post-discharge events in such patients.

We analyzed 152 acute coronary syndrome patients using multiple iron deficiency definitions: serum iron <6 µmol/L or <13 µmol/L; transferrin saturation (TSAT) <20%; ferritin <100 µg/L; and a combined definition - ferritin <100 µg/L or TSAT<20% if ferritin 100-299 µg/L. Infarct size was approximated by peak cardiac troponin T. Cox regression analysis examined associations with in-hospital complications (death, sustained arrhythmias, or Killip class ≥3) and post-discharge events (death, myocardial infarction, or stroke).

The prevalence of iron deficiency ranged from 21% to 62%, depending on definitions. Patients with deficiency defined by serum iron or TSAT were older, more frequently female, with more cardiovascular risk factors, and higher high-sensitivity C-reactive protein. Serum iron <13 µmol/L and TSAT <20% correlated with lower left ventricular ejection fraction but not with greater infarct size. Iron deficiency did not predict in-hospital complications, whereas serum iron <6 µmol/L was associated with a higher risk of post-discharge events. Such association lost significance after adjustment for hs-CRP. Lower ferritin predicted fewer events.

Iron deficiency is frequent in acute coronary syndromes. Definitions by serum iron and TSAT identify patients with worse left ventricular systolic function and more inflammation, potentially influencing prognosis.