Letter by Ribichini et al regarding article, 'Cystatin C and contrast-induced acute kidney injury'

To the Editor: On May 18, 2010, Briguori et al reported in Circulation that “in patients with chronic kidney disease, cystatin C seems to be a reliable marker for the early diagnosis and prognosis of contrast-induced nephropathy (CIN).”1 The authors investigated whether changes in cystatin C levels 24 hours after contrast media exposure anticipate the occurrence of CIN (absolute increment of serum creatinine [SC] ≥0.3 mg/dL at 48 hours), and if this could predict 12-month major adverse events such as death and need for dialysis. They found that a 24-hour increment in cystatin C levels ≥10% compared with baseline is a good predictor of CIN, with excellent negative predictive value (100%) and …