Acute renal impairment in older adults treated with percutaneous coronary intervention for ST-segment elevation myocardial infarction.

Background: Elderly individuals ( ≥ 75 years) constitute an increasing proportion of patients presenting with myocardial infarction treated with primary percutaneous coronary intervention (PCI), but only limited data are available regarding the incidence and prognostic implications of acute kidney injury (AKI) in this group of patients.
Objective: To evaluate the incidence and prognostic implications of AKI in older adults ( ≥ 75 years) with ST-segment elevation myocardial infarction (STEMI) treated with primary PCI.
Patients and Methods: A retrospective cohort, observational, single-center study of consecutive 416 older patients with STEMI (≥ 75 years) treated with primary PCI between January 2008 and August 2017 was conducted. AKI was defined as an increase of at least 0.3 mg/dl in serum creatinine within 48 h following admission.
Results: A total of 96/416 (23%) patients developed AKI. The occurrence of AKI was associated with adverse in-hospital outcomes, higher 30 days (25 vs. 6%; P < 0.001), and long-term mortality (46 vs. 17%; hazard ratio: 3.2; 95% confidence interval: 2.1-4.7; P < 0.001). Among patients with AKI, 46/96 (48%) demonstrated recovery of renal function at hospital discharge. Lack of renal function recovery at discharge (50/96 patients; 52%) was associated with the occurrence of new or progression of baseline chronic kidney disease.
Conclusion: Among older patients with STEMI undergoing primary PCI, AKI is a frequent complication associated with adverse renal short-term and long-term outcomes.