Table 3.

Multivariable Cox regression analysis of all‐cause and cardiovascular mortality

Variable	All‐cause mortality		Cardiovascular mortality
	HR (95% CI)	P‐value	HR (95% CI)	P‐value
Age (/10 years)	1.44 (1.35–1.53)	<0.001	1.33 (1.23–1.45)	<0.001
Urea (/5 mmol/L)	1.16 (1.11–1.21)	<0.001	1.16 (1.10–1.23)	<0.001
NT‐proBNP (Log10 ng/L)	1.97 (1.76–2.21)	<0.001	2.73 (2.33–3.20)	<0.001
Haemoglobin (g/dL)	0.93 (0.89–0.96)	<0.001	0.92 (0.87–0.96)	<0.001
Beta‐blocker (yes/no)	0.78 (0.70–0.87)	<0.001	0.76 (0.65–0.88)	<0.001
Loop diuretic (yes/no)	1.44 (1.26–1.63)	<0.001	1.47 (1.23–1.77)	<0.001
SIC (sq. root 1 μmol/L)	0.87 (0.81–0.95)	<0.001	1.02 (0.91–1.13)	0.75
STC (1 g/L)	0.82 (0.73–0.91)	<0.001	0.95 (0.82–1.10)	0.51
The following was added to the above model [excluding serum transferrin concentration (STC) as a continuous measure]
STC ≤ 2.3 g/L*	1.24 (1.11–1.39)	<0.001	1.15 (0.98–1.34)	0.09
The following continuous variables were added individually to the above model (excluding serum iron concentration (SIC) as a continuous variable)
TSAT (Log10) (%)	0.61 (0.45–0.83)	0.001	1.08 (0.70–1.65)	0.73
Ferritin (Log 10) (1 μg/L)	1.19 (1.01–1.40)	0.03	1.45 (1.16–1.81)	0.001
The following categorical variables were added individually to the above model [excluding serum iron concentration (SIC) as a continuous variable]
SIC ≤13 μmol/L	1.30 (1.15–1.46)	<0.001	1.04 (0.88–1.22)	0.67
TSAT <20%	1.26 (1.12–1.42)	<0.001	0.99 (0.84–1.17)	0.93
Ferritin <30 μg/L	1.03 (0.87–1.22)	0.71	0.90 (0.71–1.15)	0.41
Ferritin <100 μg/L	0.95 (0.84–1.07)	0.37	0.79 (0.67–0.93)	0.004
Guideline definition of iron deficiency	1.06 (0.94–1.20)	0.35	0.93 (0.79–1.11)	0.43

ESC, European Society of Cardiology; ID, iron deficiency; NT‐proBNP, N terminal pro‐natriuretic peptide; TSAT, transferrin saturation.