Contrast-induced acute kidney injury in patients undergoing percutaneous coronary intervention

Summary

Coronary angiography and percutaneous coronary intervention (PCI) utilising intravascular iodinated contrast agents (ICA) are being widely performed in a growing number of elderly patients with multiple comorbidities. In spite of improvements in their chemical structure, ICA still possess kidney toxicity and represent one of the main causes of contrast-induced acute kidney injury (CI-AKI) and hospital-acquired renal failure. These iatrogenic complications are associated with increased in-hospital and long-term morbidity and mortality. Development of CI-AKI prevention strategies is ongoing, but an incomplete understanding of CI-AKI pathophysiology has hampered many efforts. The most popular theories include a combination of a direct toxic effect of ICA on renal tubular cells, free radical formation and decreased renal medullary blood flow resulting in medullary ischaemia. The definition of CI-AKI includes absolute (>0.5 mg/dl [>44 μM/l]) or relative (>25%) increase in serum creatinine (SCr) 48-72 hours after exposure to ICA compared to baseline SCr values, when alternative explanations for renal impairment have been excluded.

The risk of renal function impairment associated with percutaneous diagnostic and interventional procedures is low (0.6-2.3%) in the general population. However, it may be very high (up to 50%) in some subsets, especially in patients with major risk factors such as chronic...