Are risk scores useful as predictors of developing CIN? Answer: Although it has been reported that risk scores are useful as predictors of developing CIN, their
use has not been investigated prospectively. It is inappropriate to recommend the use of risk scores at the present time. A study has reported that the risk of developing severe kidney dysfunction after PCI in patients not undergoing dialysis may be predicted with a risk scoring system (Table 3) . Table 3 CIN risk scores: 1 Variables Score Age ≥80 years 2.0 Female sex 1.5 Diabetes 3.0 Urgent priority 2.5 Emergent priority 3.5 CHF history YH25448 4.5 find more creatinine level 1.3–1.9 mg/dL 5.0 Creatinine level ≥2.0 mg/dL 10.0 IABP pre PCI 13.0 Total 16.5 Adapted from Am Heart J. 2008;155:260–266 , with permission from Elsevier Inc. CHF congestive heart failure, CIN contrast-induced nephropathy, MK-4827 order IABP intra-aortic balloon
pumping, PCI percutaneous catheter intervention However, because this risk scoring system has not been investigated prospectively, some specialists have pointed out the inappropriateness of using this scoring system in the clinical setting . It has been reported that the risk for developing CIN and the risk of requiring dialysis in patients after PCI may be predicted with a risk scoring system [49, 50]. The risks of CIN and of requiring dialysis reported in a study were 7.5 and 0.04 % among patients with a score of ≤5; 14.0 and 0.12 % among patients with a score of 6–10; 26.1 and 1.09 % among those with a score of 11–16; and 57.3 and 12.6 % among those with a score of >16, respectively (Table 4) . Table 4 CIN risk scores: 2 Risk factor Integer score Hypotension these 5 IABP use 5 CHF 5 Age >75 years 4 Anemia 3 Diabetes 3 Contrast media volume 1 for 100 mL SCr level >1.5 mg/dL 4 or eGFR (mL/min/1.73 m2) 2 for 40–60 4 for 20 to <40 6 for <20
Total score Risk score Risk of CIN (%) Risk of dialysis (%) 0–5 7.5 0.04 6–10 14.0 0.12 11–16 26.1 1.09 >16 57.3 12.60 Adapted from J Am Coll Cardiol. 2004;44:1393–1399 , with permission from Elsevier Inc. CHF congestive heart failure, CIN contrast-induced nephropathy, eGFR estimated glomerular filtration rate, IABP intra-aortic balloon pumping, SCr serum creatinine Type and volume of contrast media Does the use of a smaller volume of contrast media reduce the risk for developing CIN? (see ) Answer: The volume of contrast media is a risk factor for developing CIN. We recommend that the volume of contrast media should be the minimum necessary to obtain adequate radiographs. In a study investigating the effect of the volume of contrast media on the incidence of CIN, Cigarroa et al.  used the following formula to calculate a “contrast material limit” in patients with kidney disease: contrast material limit = ([5 mL of contrast per 1 kg] × body weight [kg])/SCr (mg/dL). However, the maximum volume of contrast is 300 mL, even when the calculated limit exceeds 300 mL.