Chen SQ, et al. - Researchers determined the clinical implications of different definitions of contrast-induced nephropathy (CIN) in consecutive patients at a single centre without baseline renal dysfunction (estimated glomerular filtration rate, eGFR ≥ 60 ml/min/1.73 m²) undergoing coronary angiography or percutaneous coronary intervention (PCI). The following two broad definitions were used to systematically assess for long-term risk of mortality following CIN: an absolute increase from baseline in serum creatinine (SCr) ≥0.3 mg/dl (mild to severe absolute CIN) and a relative increase from baseline of 25% (mild to severe relative CIN) within 72 hours. They observed that depending on definition, the incidence of CIN can range widely in patients without baseline renal dysfunction undergoing coronary angiography. Compared with relative CIN, a less common occurrence of absolute CIN was reported. Irrespective of definition, CIN was found to be related to a markedly increased risk of long-term mortality.