Long-Term Follow-Up of Patients at High Risk for Nephropathy After Contrast Exposure

Contrast medium-induced acute kidney injury (CI-AKI) is associated with morbidity and mortality, but the long-term outcomes of patients who do not develop CI-AKI remain unknown. We assessed clinical end points during long-term follow-up in patients at high risk for nephropathy who did not develop CI-AKI. Patients (n = 135) with impaired renal function (estimated glomerular filtration rate: 30-60 mL/min/1.73 m(2)) were divided into 2 groups according to contrast media (CM) exposure. The primary end point of this study was a composite outcome measure of death or renal failure requiring dialysis. Multivariate analyses identified CM exposure to be independently associated with major adverse long-term outcomes (hazard ratio: 2.3; 95% confidence interval, 1.34-6.52; P = .018). Even when CM exposure does not cause CI-AKI in patients with impaired renal function, in the long term, primary end points occur more frequently in patients exposed to CM than in those with no CM exposure.