Early versus Late Acute Kidney Injury in Patients Undergoing Primary Percutaneous Coronary Intervention.

Introduction: Acute kidney injury (AKI) frequently complicates ST-elevation myocardial infarction (STEMI) in patients undergoing primary percutaneous coronary intervention (PCI) and is associated with increased short- and long-term mortality. However, the impact of the AKI onset time following PCI on patient outcomes remains uncertain. This study aimed to investigate the timing of post-PCI AKI development and its prognostic significance in STEMI patients.

Methods: This retrospective cohort study included 2,912 STEMI patients who underwent successful PCI upon admission. The timing of AKI was determined according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria, using routine blood tests conducted during hospitalization. The primary endpoint was all-cause mortality.

Results: Among 2,912 STEMI patients studied, 222 (7.6%) developed AKI. AKI was classified as early if it occurred within 1.5 days (n = 108, 48.6%) or late if it occurred after 1.5 days (n = 114, 51.4%). Early AKI was associated with a significantly higher incidence of cardiogenic shock at presentation, lower post-PCI left ventricular ejection fraction, and increased 30-day mortality compared to late AKI. In a multivariate Cox regression analysis, early AKI emerged as an independent predictor of long-term mortality (adjusted HR 1.8, 95% CI 1.1-2.8, p = 0.015). Additionally, multivariate logistic regression analysis identified cardiogenic shock as a significant predictor of early AKI (adjusted OR 2.3, 95% CI 1.1-4.9, p = 0.03).

Conclusion: In STEMI patients, early AKI - compared to late AKI - is associated with higher short- and long-term mortality and occurs more frequently in those presenting with cardiogenic shock.