Acute Kidney Injury Definition and In-Hospital Mortality in Patients Undergoing Primary Percutaneous Coronary Intervention for ST-Segment Elevation Myocardial Infarction

Background: acute kidney injury (aki) has been associated with increased mortality in st-segment elevation myocardial infarction. we compared the mortality predictive accuracy of the 3 aki definitions used most widely for patients with st-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.methods and results: we included 3771 patients with st-segment elevation myocardial infarction treated with primary percutaneous coronary intervention at 2 italian hospitals. aki incidence was evaluated according to creatinine increases of ≥25% (aki-25),≥0.3 mg/dl (aki-0.3),and ≥0.5 mg/dl (aki-0.5). the primary end point was in-hospital mortality. overall,557 (15%),522 (14%),and 270 (7%) patients developed aki-25,aki-0.3,and aki-0.5,respectively (p<0.01). all aki definitions independently predicted in-hospital mortality (adjusted odds ratio 4.9 [95% ci 3.1-7.8],5.4 [95% ci 3.3-8.6],and 8.3 [95% ci 5.1-13.3],respectively; p<0.01 for all). at receiver operating characteristic analysis,the addition of each aki definition to combined clinical predictors of mortality (age,sex,left ventricular ejection fraction,admission creatinine,creatine kinase-mb peak) found at stepwise analysis significantly improved mortality prognostication (area under the curve increased from 0.89 for clinical predictor combination alone to 0.92 for aki-25,0.92 for aki-0.3,and 0.93 for aki-0.5; p<0.01 for all). at reclassification analysis,aki-0.5 added to clinical predictors,provided the highest score in mortality (net reclassification improvement +10% versus aki-0.3 [p=0.01] and +8% versus aki-25 [p=0.05]).conclusions: each aki definition significantly improved the mortality prediction beyond major clinical variables. aki-0.5 showed a mortality discrimination advantage,suggesting it should be the preferred definition in studies addressing st-segment elevation myocardial infarction and focusing on short-term mortality. © 2016 the authors. published on behalf of the american heart association,inc.,by wiley blackwell.