Registry-defined incident chronic kidney disease following acute kidney injury after primary PCI for STEMI and its association with long-term outcomes: a multicenter landmark analysis

Background Acute kidney injury (AKI) frequently occurs in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). Kidney recovery after AKI is heterogeneous, and the prognostic significance of kidney dysfunction persisting to the 3−6-month assessment remains incompletely defined. We evaluated whether registry-defined incident chronic kidney disease (CKD) following AKI was associated with subsequent death and myocardial infarction (MI). Methods This retrospective analysis of a prospectively collected multicenter PCI registry included STEMI patients treated with primary PCI between January 2010 and November 2020. AKI was defined according to KDIGO criteria. Kidney trajectory was classified as no AKI, transient AKI with recovery, or registry-defined incident CKD following AKI based on kidney function assessed at 3–6 months. To minimize guarantee-time bias, Kaplan–Meier and Cox analyses began at a 6-month landmark. Multivariable Cox models adjusted for age, sex, diabetes mellitus, LVEF, and baseline MDRD eGFR. Results Among 1,239 patients, 941 had no AKI, 56 had transient AKI, and 242 had incident CKD following AKI; the overall AKI incidence was 24.1%. The strict 6-month landmark cohort comprised 1,129 patients (869 no AKI, 48 transient AKI, and 212 incident CKD). Compared with no AKI, incident CKD was associated with all-cause death (multivariable Cox HR 4.06, 95% CI 1.23–13.45; P = 0.022), MI (multivariable Cox HR 4.49, 95% CI 1.79−11.30; P = 0.001), and death and/or MI (multivariable Cox HR 4.35, 95% CI 2.07−9.14; P < 0.001), whereas transient AKI was not significantly associated with these outcomes. In the two-group analysis, incident CKD was similarly associated with death (multivariable Cox HR 3.44, 95% CI 1.18−10.06; P = 0.024), MI (multivariable Cox HR 3.75, 95% CI 1.59−8.87; P = 0.003), and death and/or MI (multivariable Cox HR 3.61, 95% CI 1.83−7.14; P < 0.001). Conclusions Registry-defined incident CKD after in-hospital AKI identified a subgroup of STEMI survivors with substantially higher post-landmark risks of death and MI. Kidney recovery trajectory may provide clinically useful prognostic information beyond the occurrence of AKI alone. Trial registration ClinicalTrials.gov identifier: NCT04650529. Registered on 25 January 2021. Retrospectively registered.