Acute kidney injury following coronary angiography: a nationwide study of incidence, risk factors and long-term outcomes.

BACKGROUND: We studied the incidence and risk factors of acute kidney injury (AKI) following coronary angiography (CA) and examined short- and long-term outcomes of patients who developed AKI, including progression of chronic kidney disease (CKD).

METHODS: This was a retrospective study of all patients undergoing CA in Iceland from 2008 to 2015, with or without percutaneous coronary intervention. All procedures were performed with iso-osmolar contrast. AKI was defined according to the SCr component of the KDIGO criteria. Patients without post-procedural SCr were assumed to be free of AKI. Incident CKD was defined as 90-day sustained estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 , and progression of CKD as worsening at least one stage sustained over 90 days.

RESULTS: AKI was detected in 231 of 13,561 cases (1.7%). There was an interaction between contrast dose and preexisting kidney function, where the risk for AKI was only significant at a dose > 150 mL in patients with baseline eGFR < 45 mL/min/1.73 m2 (OR 5.3, 95% CI 2.1-14.2). The AKI patients had worse short-and long-term survival, as well as elevated hazard of both new-onset CKD (HR 3.7, 95% CI 2.7-5.0) and progression of preexisting CKD (HR 2.0, 95% CI 1.5-2.6) over a median follow-up of 3.3 years (range 0.1-8.4 years), compared to a propensity score-matched control group.

CONCLUSIONS: For iso-osmolar contrast, the risk of AKI related to contrast dose was evident for higher amount of contrast in patients with baseline eGFR < 45 mL/min/1.73 m2 . In addition to association with adverse short- and long-term survival AKI had a strong association with new-onset or progression of CKD when patients were followed longitudinally.