Serum catalytic Iron: A novel biomarker for coronary artery disease in patients on maintenance hemodialysis

Cardiovascular disease is the leading cause of morbidity and mortality in maintenance hemodialysis (MHD) patients. We evaluated the role of serum catalytic iron (SCI) as a biomarker for coronary artery disease (CAD) in patients on MHD. SCI was measured in 59 stable MHD patients. All patients underwent coronary angiography. Significant CAD was defined as a > 70% narrowing in at least one epicardial coronary artery. Levels of SCI were compared with a group of healthy controls. Significant CAD was detected in 22 (37.3%) patients, with one vessel disease in 14 (63.63%) and multi-vessel disease in eight (36.36%) patients. The MHD patients had elevated levels of SCI (4.70 ± 1.79 μmol/L) compared with normal health survey participants (0.11 ± 0.01 μmol/L) (P < 0.0001). MHD patients who had no CAD had SCI levels of 1.36 ± 0.34 μmol/L compared with those having significant CAD (8.92 ± 4.12 μmol/L) (P < 0.0001). Patients on MHD and diabetes had stronger correlation between SCI and prevalence of CAD compared with non-diabetics. Patients having one vessel disease had SCI of 8.85 ± 4.67 μmol/L versus multi-vessel disease with SCI of 9.05 ± 8.34 μmol/L, P = 0.48. In multivariate analysis, SCI and diabetes mellitus were independently associated with significant CAD. We confirm the high prevalence of significant CAD in MHD patients. Elevated SCI levels are associated with presence of significant coronary disease in such patients. The association of SCI is higher in diabetic versus the non-diabetic subgroup. This is an important potentially modifiable biomarker of CAD in MHD patients.