Anemia (Hemoglobin ≤ 13 g/dL) as a Risk Factor for Contrast-Induced Acute Kidney Injury Following Coronary Angiography

Contrast-induced acute kidney injury (CI-AKI) following coronary angiography is associated with increased mortality. The association between severity of anemia and CI-AKI following coronary angiography is not well-established. In this retrospective study, we aimed at assessing the association of anemia of various severity with the risk of CI-AKI in patients who underwent coronary angiography. We included all patients who underwent coronary angiography with or without percutaneous coronary intervention from January 2012 to December 2016 at a single tertiary care hospital. CI-AKI was defined as ≥0.3 mg/dL increase in creatinine from baseline and anemia was defined as baseline hemoglobin ≤13 g/dL. Patients were stratified into three subgroups-mild (11.1 to 13.0 g/dL), moderate (9.1 to 11.0 g/dL) and severe anemia (7.0 to 9.0 g/dL). Crude and adjusted odds ratios (AOR) were calculated using univariate multiple logistic regression analysis. Of 2,055 patients (females = 30.7%, mean age 58.0 ± 12.5 years) who underwent coronary angiography, 293 (14.3%) developed CI-AKI. Presence of anemia was associated with increased risk of developing CI-AKI (AOR = 5.3, 95% confidence interval [CI] = 3.8 to 7.3, p < 0.001). Risk of CI-AKI was increasingly higher with increasing severity of the anemia; mild (AOR = 3.4, 95% CI = 2.5 to 4.7, p < 0.001), moderate (AOR = 9.8, 95% CI = 6.9 to 14.2, p < 0.001) and severe (AOR = 13.7, 95% CI = 8.2 to 23.1, p < 0.001). In conclusion, severity of anemia is a strong predictor of CI-AKI following coronary angiography.