The prevalence and prognosis of contrast-induced acute kidney injury according to the definition in patients with acute myocardial infarction who underwent primary percutaneous coronary intervention

Background: Contrast-induced acute kidney injury (CI-AKI) is associated with adverse outcomes. However, the problem complicating CI-AKI relates to its definition. More than 30 definitions of AKI have been used in the literature. We examined the prevalence of CI-AKI according to three criteria. Prevalence of cardiovascular events according to each criterion was also investigated. Methods: We studied 247 consecutive patients with acute myocardial infarction (66.7 ± 9.0 years, 189 males) who underwent primary percutaneous coronary intervention in our hospital. Three definitions of CI-AKI were applied: (i) traditional CI-AKI, (ii) CI-AKI derived from RIFLE criteria, (iii) CI-AKI derived from AKIN criteria. Cardiovascular events comprised in-hospital death, sudden death, cerebral infarction, heart failure, and acute coronary syndrome. Results: Prevalence of CI-AKI was 27.1% (67/247) according to the traditional CI-AKI definition, 23.9% (59/247) according to the CI-AKI definition derived from RIFLE criteria, and 15.8% (39/247) according to the CI-AKI definition derived from AKIN criteria. Prevalence of cardiovascular events was 13.8% (34/247). Prevalence of cardiovascular events with and without CI-AKI was 19.4% (13/67) and 11.7% (21/180) according to the traditional CI-AKI definition (P = 0.13), 22.0% (13/59) and 11.2% (21/188) in the CI-AKI definition derived from RIFLE criteria (P = 0.035), and 35.9%(14/39) and 9.6% (20/208) according to the CI-AKI derived from AKIN criteria (P = 0.00001). Conclusion: Prevalence of CI-AKI varies widely depending on the criteria used. The CI-AKI definition derived from AKIN criteria was the most effective predictor of cardiovascular events