The duration of acute kidney injury after cardiac surgery increases the risk of long-term chronic kidney disease.

BACKGROUND: Acute kidney injury (Dasta et al., Nephrol Dial Transplant 23(6):1970-1974, 2008) following cardiac surgery is associated with higher perioperative morbidity and mortality, but its impact on long term development of chronic kidney disease (CKD) is uncertain.

METHODS: A total of 350 patients submitted to elective cardiac surgery were evaluated for AKI, defined as an increase in serum creatinine (SCr) ≥ 0.3 mg/dL over baseline value. Univariate and multivariate analysis were used to study pre, intra and postoperative parameters associated with occurrence CKD after 12 months of follow-up.

RESULTS: AKI incidence was 41 % (n = 88). The 12-month prevelence of CKD was 9 % (n = 19) in non-AKI patients versus 25 % (n = 54, p < 0.0001) in the AKI group. The factors identified as independent risk factors for long-term CKD development in the multivariate logistic regression model were age >60 years, hospitalization serum creatinine >0.8 mg/dL, peripheral artery disease, hemorrhage and AKI duration > 3 days.

CONCLUSION: Patients developing AKI after cardiac surgery presented high prevalence of long-term incident CKD. The duration of AKI was a strong independent risk factor for this late CKD development. Recognition of predictive factors for CKD development following cardiac surgery-associated AKI may help to develop strategies to prevent or halt CKD progression in this population.