What is the clinical evidence from this study?

Study design: Cohort. Population: New-onset chronic heart failure (n=9477). Intervention: Iron deficiency (TSAT < 20%, serum iron ≤13 μmol/L, or ESC guidelines) vs. No iron deficiency. Primary outcome: All-cause mortality (TSAT < 20% in non-anaemic patients) (HR 1.57, 95% CI 1.30-1.89).

November 6, 2024Open Access

Prognostic Impact of Iron Deficiency in New-Onset Chronic Heart Failure: Danish Heart Failure Registry Insights

Q: What are the key findings of this study?

Iron deficiency defined by TSAT <20% was associated with increased all-cause mortality in non-anaemic patients with new-onset chronic heart failure (HR 1.57; 95% CI 1.30-1.89).

Key Result

Iron deficiency defined by TSAT <20% was associated with increased all-cause mortality in non-anaemic patients with new-onset chronic heart failure (HR 1.57; 95% CI 1.30-1.89).

Study Design

Type

Cohort (n=9,477)

Multicenter

Yes

Structured PICO

Does the definition of iron deficiency impact its prognostic value for mortality and hospitalization in patients with new-onset chronic heart failure?

Population

9,477 patients with new-onset chronic heart failure registered in the Danish Heart Failure Registry from April 2003 to December 2019.

Intervention

Presence of iron deficiency defined by four criteria: ESC guidelines (ferritin <100 ng/mL or ferritin 100-299 ng/mL and TSAT <20%), ferritin <100 ng/mL, TSAT < 20%, and serum iron ≤13 μmol/L.

Comparator

Absence of iron deficiency according to the respective definitions.

Outcome

All-cause mortality, cardiovascular mortality, and first hospitalization for heart failure.hard clinical

Iron deficiency defined by TSAT < 20% or serum iron ≤13 μmol/L provides better prognostic value for mortality in new-onset chronic heart failure regardless of anaemia status compared to the current ESC guideline definition.

Main Result

Effect estimate: HR 1.57 (95% CI 1.30-1.89)

Abstract

AIMS: Iron deficiency (ID) is prevalent in chronic heart failure (HF) but lacks a consensus definition. This study evaluates the prevalence and the prognostic impact of ID using different criteria on all-cause and cardiovascular mortality, as well as first hospitalization for HF in patients with new-onset chronic HF. METHODS: In this nationwide registry-based cohort, we explored four definitions of ID: the current European Society of Cardiology (ESC) guidelines ferritin 13 μmol/L and TSAT > 20%. Regardless of anaemia status, ID defined by TSAT < 20% or serum iron ≤13 μmol/L was associated with all-cause mortality [non-anaemic, hazard ratio (HR): 1.57, 95% confidence interval (CI): 1.30-1.89 and HR: 1.47, 95% CI: 1.24-1.73; anaemic, HR: 1.22, 95% CI: 1.07-1.38 and HR: 1.25, 95% CI: 1.09-1.44, respectively and cardiovascular mortality (non-anaemic, HR: 2.21, 95% CI: 1.59-3.06 and HR: 1.47, 95% CI: 1.12-1.95; anaemic, HR: 1.37, 95% CI: 1.11-1.69 and HR: 1.28, 95% CI: 1.02-1.61, respectively), as well as increased risk of first hospitalization for HF (non-anaemic, HR: 1.28, 95% CI: 1.09-1.1.50 and HR: 1.27, 95% CI: 1.10-1.46; anaemic, HR: 1.25, 95% CI: 1.08-1.44 and HR: 1.22, 95% CI: 1.05-1.42, respectively). ID defined by ESC guidelines was associated with all-cause and cardiovascular mortality only in non-anaemic patients (HR: 1.41, 95% CI: 1.18-1.1.70 and HR: 1.58, 95% CI: 1.18-2.12.). Furthermore, the ESC guideline definition was associated with increased risk of first hospitalization for HF, regardless of anaemia status (non-anaemic, HR: 1.26, 95% CI: 1.08-1.1.47; anaemic, HR: 1.34, 95% CI: 1.17-1.53). CONCLUSIONS: ID, when defined by TSAT < 20% or serum iron ≤13 μmol/L, is associated with increased risk of all-cause and cardiovascular mortality, as well as first hospitalization for HF in patients with new-onset chronic HF, regardless of anaemia status. Conversely, ID defined as ESC guidelines is associated with all-cause and cardiovascular mortality only in non-anaemic patients.