Prognostic value of iron, nutritional status indexes and acute phase protein in acute coronary syndromes

The relation between the inflammatory status during unstable angina and nutritional parameters has not been well described. We sought to investigate the relation between the acute inflammatory status, as evaluated on the basis of high C-reactive protein (CRP) and serum amyloid A levels and laboratory indexes of iron and nutritional status in patients with unstable angina, and whether the variations in iron levels have a prognostic significance.

The study population consisted of 98 patients admitted to our facility with unstable (group 1: 64 consecutive patients, 52 males, 12 females, mean age 66 +/- 10 years) or stable angina (group 2: 34 patients, 30 males, 4 females, mean age 65 +/- 9 years). The hemoglobin levels, the erythrocyte mean cell volume, serum iron levels, the increase in transferrin levels, the decrease in the percent transferrin saturation, ferritin levels, the nutritional status, and the CRP and serum amyloid A levels were measured.

On the basis of a CRP value > 1 mg/dl, 47 patients with unstable angina and 4 patients with stable angina were identified as having active inflammatory disease. The presence of inflammation was associated with significantly lower mean values of hemoglobin, erythrocyte mean cell volume, serum iron and transferrin levels, and percent transferrin saturation in comparison with patients without inflammation. A significant inverse correlation coefficient between a CRP level > 1 mg/dl and hemoglobin, transferrin levels and percent transferrin saturation was observed: the strongest correlation was with serum iron levels. The relative risk of total cardiac events was significantly greater in patients with low serum iron levels than in those with high serum iron levels.

Patients with acute inflammation present altered iron status indexes. Increased CRP levels and reduced serum iron levels are associated with a worse outcome in patients with unstable angina.