Beyond the Guidelines: The Critical Role of Type 1 Iron Deficiency in Predicting Mortality in Patients with Heart Failure

OBJECTIVE
The criteria of iron deficiency (ID) could include depleted iron stores with unmet cardiomyocyte iron demands, which could serve as predictors of adverse outcomes in patients with heart failure (HF).


METHODS
We included 570 patients with HF. According to new proposed definitions of ID, we classified patients with HF into three groups as follows: type 1 (moderate to severe hypoferraemia TSAT< ≈15-16% with anemia), type 2 or 3 (mild hypoferraemia TSAT<≈20% with no or mild anemia) and HF guideline ID criteria. Binary logistic regression analysis was employed to define independent predictors for 1-year all-cause mortality in patients with HF. We performed Cox proportional hazard regression models to establish the effect of type 1 ID on mortality.


RESULTS
Out of 570 patients with HF, type 1 ID was in 175 (30.7%) patients, type 2 or 3 ID in 250 (43.9%) patients, and guideline ID criteria in 415 (72.8%) patients, respectively. 1-year all-cause mortality was observed in 38.3% for type 1 ID, 22.7% for type 2 or 3 ID, and 26.0% for those meeting guideline ID criteria, respectively. Increased age (OR: 1.054, 95%CI: 1.025-1.084) and type 1 ID (OR: 1.830, 95%CI: 1.044-3.208) were independent predictors for 1-year all-cause mortality. Cox regression analysis showed that an increased mortality risk was observed in HF patients with type 1 ID versus without type 1 ID, both in unadjusted (HR: 2.289, 95%CI: 1.644-3.186, p<0.001) and adjusted (HR: 1.543, 95%CI: 1.070-2.225, p=0.020) analyses.


CONCLUSION
Type 1 ID was an independent predictor for 1-year all-cause mortality in patients with HF, unlike type 2 or 3 ID and guideline-defined ID. Type 1 ID in patients with HF identified an increased overall mortality risk compared to HF patients without type 1 ID.