Among patients presenting with ST-segment elevation myocardial infarction (STEMI) for primary percutaneous coronary intervention (PCI), the associations between clinical outcomes and both baseline renal function and the development of acute kidney injury (AKI) have not been reported in a trial population with unselected baseline renal function.

Patients enrolled in the APEX-AMI trial who underwent primary PCI for the treatment of STEMI were categorized according to (a) baseline renal function and (b) the development of AKI. Patient characteristics, clinical outcomes, and treatment patterns were analyzed according to baseline renal function and the development of AKI. A prediction model for AKI after primary PCI for STEMI was also developed.

A total of 5,244 patients were included in this analysis and stratified according to baseline estimated glomerular filtration rate (eGFR) (milliliters per minute per 1.73 m²) of >90, 60 to 90, 30 to 59, or <30 or as dialysis dependent. Patients with lower eGFR were older, more often female, and less often treated with evidence-based medicines and had worse angiographic outcomes and higher mortality. The rates of AKI for patients with a baseline eGFR of >90, 60 to 90, 30 to 59, and <30 were 2.5%, 4.1%, 8.1%, and 1.6%, respectively (P < .0001). The strongest predictors of AKI were age and presenting in Killip class III or IV.

Among patients undergoing primary PCI for STEMI, impaired renal function at presentation and development of post-PCI AKI were highly associated with worse clinical and angiographic outcomes, including death. The risk of developing AKI was low and only modestly associated with baseline renal function.