Contrast-induced nephropathy after percutaneous coronary intervention in simple lesions: risk factors and incidence are affected by the definition utilized.

Aim To compare the incidence, and risk factors, in-hospital and at the 18-month prognosis of contrastinducednephropathy (CIN) according to the definition utilized: as an increase in serum creatinine (Scr) 0.5mg/dL (CIN 1) or as an increase in Scr 25% above baseline values (CIN 2).Methods and Results We prospectively evaluated CIN according to two different definitions in 150 patientswho underwent percutaneous coronary intervention (PCI) in simple lesions employing a low-mediumdose of contrast media. Incidence of CIN was higher using the CIN 2 definition than CIN 1 (9.3% vs. 4%;p=0.0133). Patients with CIN 1 had a higher incidence of chronic kidney disease (CKD) (66.7% vs. 13.9%;p=0.006), higher mean serum creatinine levels (1.35±0.42 vs. 0.98±0.35; p=0.001) and lower mean eGFRlevels (58.3±19.6 vs. 84±25.9; p=0.002). Patients with CIN 2 had a higher incidence of anemia (57.1% vs.30.9%; p=0.049) and a higher mean contrast media volume was used (142.6±62.2 mL vs. 110.6±57.2 mL;p=0.05). In the multivariate analysis the only significant variable associated with CIN (CIN 2) was a highervolume of contrast media (OR=1.01; p=0.04). There were no differences in the major in-hospital events, butpatients with CIN (both definitions) had a longer in-hospital stay. A persistent rise in serum creatinine at dischargeoccurred in only one patient. There were no differences between patients with and without CIN inevents at the follow-up, with the exception of an increased risk of new hospitalization in patients with CIN 2.Conclusion After PCI employing low-medium dose of contrast media the incidence of CIN varied accordingto the definition used. Neither of the two definitions offers additional information compared with theother. Chronic kidney disease and baseline parameters of renal function are the risk factors associated withCIN 1; anemia and higher volume of contrast media are associated with CIN 2.