Acute kidney injury in acute coronary syndromes - An important multifactorial consequence.

Introduction: Acute kidney injury (AKI) is a pathological phenomenon with a negative impact on outcomes in different clinical scenarios. Its mechanism in acute coronary syndrome (ACS) is not completely understood, and measures to prevent it are not uniform. We set out to study the incidence, clinical relevance, predictors and possible implications for patient management of AKI in ACS.

Methods: Using data from a multicenter national registry on ACS, we retrospectively analyzed predictors of AKI and its impact on outcomes (in-hospital complications and one-year mortality). All ACS types were included. AKI was defined as an increase in serum creatinine of ≥0.3 mg/dl (≥26.4 μmol/l) and/or by ≥1.5 times baseline.

Results: A total of 7808 ACS patients were included in the analysis, 1369 (17.5%) of whom developed AKI. AKI was shown to be an independent predictor of in-hospital major bleeding (odds ratio [OR] 2.09; 95% confidence interval [CI] 1.19-3.64; p=0.01), mortality (OR 4.72; 95% CI 2.94-7.56; p<0.001) and one-year mortality (hazard ratio 2.01; 95% CI 1.51-2.68; p<0.001). The incidence of AKI was associated with older age, history of hypertension, renal failure and stroke/transient ischemic attack, Killip class >1 on admission and left ventricular ejection fraction <50%. Performance of coronary angiography or angioplasty were not associated with AKI. Diuretics during admission were predictors of AKI only in patients in Killip class 1.

Conclusions: AKI is an important finding in ACS, with a significant impact on hard clinical endpoints such as in-hospital and one-year mortality. It is associated with easily identifiable clinical factors and an invasive strategy does not increase its incidence.