What do small serum creatinine changes tell us about outcomes after acute myocardial infarction?

Acute kidney injury (AKI), mostly defined as a rise in serum creatinine concentration of more than 0.5 mg/dl, is a common, serious, and potentially preventable complication of percutaneous coronary intervention and is associated with adverse outcomes including an increased risk of inhospital mortality. Recent data from the National Cardiovascular Data Registry/Cath-PCI registry including 985,737 consecutive patients undergoing percutaneous coronary intervention suggest that approximately 7% experienced AKI with a reported incidence of 3-19%. In patients undergoing primary percutaneous coronary intervention for acute myocardial infarction (AMI), AKI occurs more frequently with rates up to 20% depending on patient and procedural characteristics. However, varying definitions of AKI limit comparisons of AKI rates across different studies. Recently, most studies have adopted the Acute Kidney Injury Network (AKIN) criteria for definition and classification of AKI. Beyond the AKIN criteria for AKI, other classifications such as the risk, injury, failure, loss and end-stage kidney disease (RIFLE) and kidney disease: improving global outcomes (KDIGO) criteria are used to define AKI. Notably, even small increases in serum creatinine beyond AKI may be associated with adverse outcomes including increased hospital length of stay and excess. Acute kidney injury (AKI) is a serious and potentially preventable complication of percutaneous coronary intervention (PCI). Worsening renal function is associated with adverse outcomes including a higher rate of in-hospital mortality. In patients undergoing primary PCI for acute myocardial infarction (AMI), AKI occurs up to 20% of such individuals. Varying definitions of AKI limit comparisons of AKI rates across different studies. Additionally, even small increases in serum creatinine beyond lavels meeting AKI definitions may be associated with adverse outcomes including increased hospital length of stay.