Iron deficiency and all-cause mortality after myocardial infarction

Abstract Introduction Iron deficiency (ID) is commonly associated with cardiovascular diseases, including myocardial infarction (MI). However, the data on the clinical significance of ID in patients with MI are conflicting. This may be related to the use of various ID criteria. Purpose Our study aimed to compare the association of different ID criteria with all-cause mortality after MI. Methods Consecutive patients hospitalized at a large tertiary heart center for type 1 MI without previous history of coronary artery disease were included. We evaluated the association of different iron metabolism parameters measured on the first day after hospital admission with all-cause mortality during the follow-up. Results Of a cohort of 1,156 patients included (aged 64±12 years, 25% women), 194 (16.8%) died during the median follow-up of 3.4 years (IQR 626-1782 days). A total of 51,7% of post-MI patients had low iron levels (≤13 µmol/L), and 16,3% of them had iron level ≤12.8 µmol/L and soluble transferrin receptor (sTfR) ≥3 mg/L. After multivariate adjustment, iron level ≤13 µmol/L (HR 1.67, 95% CI 1.19-2.34) and the combination of iron level ≤12.8 µmol/L and sTfR ≥3 mg/L (HR 2.56, 95% CI 1.64-3.99) were associated with an increased risk of mortality. This information provided additional predictive value to the GRACE score. No association between ferritin level and mortality was found. Compared to the model which contains iron level, the addition of sTfR improved risk stratification (net reclassification improvement 0.61, 95% CI 0.52-0.69) by reclassifying patients into a higher-risk group. Conclusion ID is common among patients with the first MI. The criteria based on iron and soluble transferrin receptor levels provide the best prediction of mortality, and should be evaluated in future interventional studies with intravenous iron therapy.Kaplan-Meier survival for iron levelsK-M survival for combined ID parameters