The study, published in Frontiers in Cardiovascular Medicine, drew on a prospectively collected registry of STEMI patients treated with primary PCI between January 2010 and November 2020. The researchers then classified each patient's kidney trajectory into one of three categories based on kidney function measured at three to six months: no AKI, transient AKI with recovery, or registry-defined incident chronic kidney disease following AKI. Of the 1,239 patients analyzed, 941 never developed AKI, 56 had transient AKI that recovered, and 242 progressed to incident chronic kidney disease after the injury, yielding an overall AKI incidence of 24.1 percent.

That figure underscores how common kidney complications are in this population. A central methodological challenge in studies like this one is guarantee-time bias. To address this, the investigators used a landmark analysis: all survival and event tracking began at a six-month landmark, after kidney trajectories had been established.

In the strict six-month landmark cohort of 1,129 patients, comprising 869 patients without AKI, 48 with transient AKI, and 212 with incident chronic kidney disease, the differences in long-term outcomes were striking. Compared with patients who had no AKI, those with incident chronic kidney disease had a hazard ratio of 4.06 for all-cause death, 4.49 for myocardial infarction, and 4.35 for the composite of death and/or myocardial infarction. Transient AKI with recovery, by contrast, was not significantly associated with any of these outcomes.

The findings held up in a two-group analysis that pooled transient AKI with the no-AKI group for comparison. Incident chronic kidney disease was associated with a hazard ratio of 3.44 for death, 3.75 for myocardial infarction, and 3.61 for death and/or myocardial infarction. All multivariable Cox models adjusted for age, sex, diabetes mellitus, left ventricular ejection fraction, and baseline estimated glomerular filtration rate calculated with the MDRD equation, meaning the association persisted after accounting for these established predictors of cardiovascular risk.

What this study adds is the suggestion that the trajectory of kidney function after an acute insult, rather than the insult itself, carries the prognostic weight. Kidneys that recover appear to restore a risk profile closer to that of patients who were never injured. The authors conclude that registry-defined incident chronic kidney disease after in-hospital AKI identifies a subgroup of STEMI survivors with substantially higher post-landmark risks of death and myocardial infarction, and that kidney recovery trajectory may provide clinically useful prognostic information beyond the occurrence of AKI alone.

Several limitations temper the findings. The analysis is retrospective, relying on registry data collected over a decade at multiple centers, and the transient AKI group was small, with only 48 patients in the landmark cohort, which limits the precision of estimates for that subgroup. Acute kidney injury after emergency stent surgery for STEMI is common, but it is the patients whose kidney function remains impaired months later who bear a markedly elevated burden of death and recurrent infarction.

Monitoring kidney recovery as a dynamic variable, rather than treating AKI as a single yes-or-no event, may sharpen long-term risk prediction in this high-stakes population.

Subject of Research: Incident chronic kidney disease after acute kidney injury following primary PCI for STEMI and its association with long-term death and myocardial infarction

Article Title: 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

Article References: Kim, Y.-L., Jang, J. Y., Bae, J., Cho, Y.-H., Shin, Y., Lee, H. J., Noh, M. S., Park, J. R., Kang, M. G., Kim, H. R., Lee, H. J., Kim, K.-H., Hwang, J. Y., Park, S.-E., & Ahn, J.-H. (2026). 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. Frontiers in Cardiovascular Medicine, 13, 1933650. https://doi.org/10.3389/fcvm.2026.1933650

Image Credits: AI Generated

DOI: 10.3389/fcvm.2026.1933650

Keywords: acute kidney injury, chronic kidney disease, STEMI, primary PCI, landmark analysis, cardiorenal syndrome, myocardial infarction, KDIGO criteria, risk prediction, multicenter registry, Registry-defined, incident