Associations Between Hemoglobin and Serum Iron Levels and the Risk of Mortality Among Patients with Coronary Artery Disease.

BACKGROUND

This study aimed to investigate the relationship between hemoglobin and serum iron levels and mortality risk in patients with coronary artery disease (CAD).

METHODS

We analyzed data from 3224 patients with CAD using Cox proportional hazards regression models to assess the association of hemoglobin and serum iron levels with cardiovascular and all-cause mortality from the Guangdong coronary artery disease cohort.

RESULTS

Over a median follow-up period of 8.9 years, 636 patients died, including 403 from cardiovascular causes. Higher hemoglobin and serum iron levels were linked to a reduced risk of cardiovascular and all-cause mortality. Patients in the highest quartiles of hemoglobin and serum iron levels had multivariable-adjusted hazard ratios (HRs) of 0.62 (95% CI, 0.46-0.85) and 0.51 (95% CI, 0.37-0.69) for cardiovascular mortality and 0.64 (95% CI, 0.50-0.83) and 0.67 (95% CI, 0.53-0.85) for all-cause mortality, compared with those in the lowest quartile. A one-standard-deviation increase in hemoglobin and serum iron levels corresponded to a 19% and 24% reduction in cardiovascular mortality risk and a 19% reduction in all-cause mortality risk for both factors. Restricted cubic spline analysis revealed L-shaped and U-shaped associations between hemoglobin and serum iron levels and cardiovascular and all-cause mortality, respectively.

CONCLUSIONS

Hemoglobin and serum iron levels were significantly associated with lower risks of cardiovascular and all-cause mortality in patients with CAD. Further research is needed to evaluate the effects of iron supplementation in these patients.