Background: The aim of the present study was to assess the influence of anemia on the risk of developing contrast-induced nephropathy after percutaneous coronary angioplasty.
Methods: Serum creatinine values were measured before and within 48 h after the administration of contrast agents. Contrast-induced nephropathy (CIN) was defined as an increase of ≥ 0.5 mg/dl or ≥ 25 % in serum creatinine concentration over baseline within 48 h after administration. Anemia was defined as hemoglobin <120 g/l in women and <130 g/l in men.
Results: Among the 1,026 patients studied, 32 (3.1 %) developed CIN after procedure. CIN occurred in 6.3 % of the anemic patients and in 2.2 % of the non-anemic patients (P < 0.01). The incidence of CIN increased with decreasing of baseline estimated glomerular filtration rate (eGFR) in both the anemia and non-anemia groups. In patients with baseline eGFR <30 ml/min, a high proportion of both anemic and non-anemic patients experienced CIN (24.6 vs. 17.5 %). When baseline eGFR was 30-59 ml/min, the incidence of CIN in anemic patients was twofold higher than in non-anemic patients (7.9 vs. 3.8 %; P < 0.05). Multivariate logistic regression analysis found that baseline eGFR and baseline hemoglobin were independent predictors of CIN.
Conclusion: Anemia is associated with a higher incidence of CIN in patients with moderate renal dysfunction. Patients with both preexisting renal insufficiency and anemia are at high risk of CIN. Baseline eGFR and baseline hemoglobin are independent predictors of CIN.