Should we use ferritin in the diagnostic criteria of iron deficiency in heart failure patients?

Background and aims: Iron deficiency (ID) is a common comorbidity in patients with chronic heart failure (HF) and is associated with worse prognosis. We aimed at comparing the currently European Society of Cardiology (ESC) criterion for diagnosis of ID (ferritin < 100 μg/L or ferritin 100-299 μg/L with transferrin saturation [TSAT] < 20%) with either isolated low TSAT or isolated low ferritin on survival, in a cohort of HF patients.

Methods: This was an observational prospective study, investigating ambulatory patients with HF and reduced ejection fraction (n = 108). All patients were assessed for clinical aspects and iron indexes. The primary endpoint was all-cause death.

Results: Abnormal iron status was observed in 50 (46%) of patients. During the median follow-up time of 857.5 [647-899] days, 31 patients died (29%). In univariate analyses ESC-criterion (p = 0.022) and isolated TSAT <20% (p = 0.002), but not isolated ferritin <100 μg/L (p = 0.439), were significantly related to an increased risk of all-cause death. However, in multivariate analyses only TSAT <20% (HR = 2.3; [95% CI: 1.11-4.85]; p = 0.026) was independently related to all-cause mortality.

Conclusions: Our results indicated that diagnosis of ID based on isolated TSAT <20% identifies HF patients with worse prognosis, while ferritin was not associated with mortality risk, suggesting that ferritin should not be taken into account for evaluation of clinical impact of ID in HF patients.