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.

Is carbon dioxide a safe and good alternative for diatrizoate meglumine as a contrast in digital subtraction angiography?

Contrast-induced nephropathy is well-known sequelae of iodinated contrast (diatrizoate meglumine). Carbon dioxide (CO(2)) can be used as an alternative contrast agent. The aim of this study was to compare the renal injury and the quality of images of aortogram using iodinated contrast versus CO(2) using digital subtraction angiography (DSA). This prospective randomized study was done in 29 healthy dogs using DSA aortogram. Dogs were randomly assigned to receive iodinated contrast or CO(2). 6-F pigtail catheter was introduced via femoral artery approach to perform aortogram under general anesthesia. Serum creatinine (S.Cr.) and urinary enzymes, namely: N-acetyl D-glucosaminidase (NAG), alanine aminopeptidase (AAP), and gamma glutamyl transferase (GGT), were measured before and 48 hours after aortogram. There was no change in S.Cr. in both the groups. Significantly more enzymuria was seen following iodinated contrast than CO(2). Enzymuria pre and postaortogram following the iodinated contrast was GGT: 14.9 +/- 5.92 vs. 26.2 +/- 15.1 (P = 0.001), NAG: 1.63 +/- 0.90 vs. 3.6 +/- 2.14 (P = 0.0001), and AAP: 1.51 +/- 0.75 vs. 3.38 2.41 (P = 0.001), and in the CO(2) group was GGT: 15.5 +/- 4.9 vs. 21.1 +/- 9.04 (P = 0.02), NAG: 2.12 +/- 1.06 vs. 3.82 3.27 (P = 0.08), and AAP: 1.28 +/- 0.76 vs. 2.51 +/- 1.72 (P = 0.03). More than 50% increase over the preprocedural value was significantly less following CO(2). Images obtained with iodinated contrast were superior to those with CO(2,) however, the quality of image with CO(2) was adequate for delineation of the renal artery and major branches. Both iodinated contrast and CO(2) cause significant enzymuria. More severe enzymuria (>50% increase) was seen significantly less with the use of CO(2). Quality of images is better with iodinated contrast.