Impact of anemia on contrast-induced nephropathy (CIN) in patients undergoing percutaneous coronary interventions

Wen-hua Li 0 Dong-ye Li 0 Fei Han 0 Tong-da Xu 0 Yang-bing Zhang 0 Hong Zhu 0 0 W. Li (&) D. Li F. Han T. Xu Y. Zhang H. Zhu Department of Cardiology, Affiliated Hospital of Xuzhou Medical College , No. 99 Huihai west Road, Xuzhou 221002, China 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 C0.5 mg/dl or C25 % 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. - Contrast-induced nephropathy (CIN) is an iatrogenic disorder resulted from exposure to contrast media. The term CIN indicates an impairment of renal function (the elevation of serum creatinine by C0.5 mg/dl or C25 %) occurring within 3 days following the intravascular administration of contrast media, not attributable to other causes [13]. CIN is associated with increased morbidity and mortality, particularly in high-risk patients who have undergone coronary angiography and/or percutaneous coronary interventions. Although many studies demonstrate that preexisting renal dysfunction, diabetes mellitus, older age and reduced left ventricular systolic function are the most important risk factors for CIN, the association between baseline hemoglobin and CIN after injection of contrast agents has not been completely clarified. We hypothesize that anemic patients would be an increased risk of developing CIN due to renal ischemia. In this study, we examined the effect of anemia on the rates of CIN in patients undergoing percutaneous coronary intervention. Objects and methods Between January 1, 2008, and October 31, 2009, a total of 1,026 patients who had undergone coronary intervention procedure were enrolled in this study. Among them 622 were men and 404 women; median age was 64 (3281 years). This study was conducted in accordance with the declaration of Helsinki. This study was conducted with approval from the Ethics Committee of Affiliated Hospital of Xuzhou Medical College. Written informed consent was obtained from all participants. Patients with reduced renal function were hydrated with 0.9 % saline at 1 ml/kg/h for 12 h before and after catheterization. For emergency coronary interventional procedures, physiologic (0.9 %) saline was given intravenously at a rate of 1 ml/kg/h for 12 h after contrast exposure. In patients with left ventricular ejection fraction (LVEF) \40 % or overt heart failure, the hydration rate was reduced to 0.5 ml/kg/h. A nonionic, low-osmolality contrast agent was used almost exclusively in our laboratory. All selective patients provided written informed consent for PCI. Study protocols and definitions Serum creatinine concentrations were measured before and within 48 h of administration of contrast agents in every patient, and further measurements were performed in all patients developing CIN. Data were entered in a database that contained demographic, clinical and angiographic data. Anemia was defined as hemoglobin (Hgb) \120 g/l in women and \130 g/l in men, according to the World Health Organization criteria [4]. Renal function was assessed by the estimated glomerular filtration rate (eGFR) using the MDRD formula for Chinese patients [5]: GFR (ml/min/ 1.73 m2) = 175 9 Scr (mg/dl)-1.154 9 age-0.203 9 (0.79 if female). This equation gives a more accurate assessment of renal function than serum creatinine alone. Renal function was categorized according to the stages set by the National Kidney Foundation, with C90 ml/min normal, 6089 ml/min mildly impaired, 3059 ml/min moderately impaired and \30 ml/min severely impaired. Contrast-induced nephropathy (CIN) was defined as the elevation of serum creatinine by C0.5 mg/dl or C25 % occurring (...truncated)