Mild Renal Insufficiency Linked to Higher Inflammation and Increased Mortality Risk in STEMI Patients: Study

"Even mild renal insufficiency (eGFR 60–89 mL/min/1.73 m²) was associated with a twofold increase in one-year mortality risk (HR 2.18) in STEMI patients and correlated with elevated neutrophil-lymphocyte ratio (NLR) at admission. Inflammation contributed to 1.7% of this link. Incorporating estimated glomerular filtration rate (eGFR) and neutrophil-lymphocyte ratio (NLR) into the risk model enhanced mortality prediction accuracy from 73% to 80% (C-index: 0.799)," the researchers reported in Scientific Reports.

Systemic inflammation progressively worsens with declining kidney function, yet the impact of mild renal insufficiency on inflammatory response at admission and its influence on clinical outcomes in STEMI patients remains unclear. Therefore, Jing Chen, Cardiovascular Research Institute of Wuhan University, Wuhan, People’s Republic of China, and colleagues explored the relationship between eGFR and NLR at admission, assessing their combined, interactive, and mediating effects on one-year mortality risk in STEMI patients.

For this purpose, the researchers conducted a retrospective analysis of 5,594 consecutive STEMI patients who underwent primary PCI across seven high-volume centers in China between 2015 and 2021. They assessed kidney function using the estimated glomerular filtration rate (eGFR) and inflammatory status with the neutrophil-lymphocyte ratio (NLR) at admission. The study investigated their combined impact on one-year mortality, employing statistical models to evaluate interactions, mediation effects, and predictive accuracy.

The following are the key findings of the study:

• Mildly reduced eGFR (60–89 mL/min/1.73m²) was linked to higher NLR at admission and an increased 1-year mortality risk (HR 2.18).
• Inflammation at admission contributed to 1.7% of the association between reduced eGFR and mortality risk.
• Adding eGFR and NLR to a predictive model improved mortality prediction accuracy (C-index 0.799 vs. 0.730) and enhanced risk classification (net reclassification index 0.334).

This study highlights that even mild renal insufficiency is consistently associated with heightened inflammation at admission and an increased risk of 1-year mortality following STEMI. Inflammatory status plays a small but significant role in this relationship.

The researchers emphasized that integrating eGFR and NLR into risk models improves mortality prediction, facilitating the early identification of high-risk patients who may benefit from intensive kidney monitoring and timely intervention. They concluded that these findings also highlight the need for developing targeted anti-inflammatory therapies for STEMI patients with renal insufficiency.

Reference:

Luo, D., Wang, X., Wang, L., Hu, Z., Zhang, B., Xu, C., Jiang, H., & Chen, J. (2025). Association between mild renal insufficiency, inflammatory status on initial admission, and 1-year mortality following ST-segment elevation myocardial infarction. Scientific Reports, 15(1), 1-9. https://doi.org/10.1038/s41598-025-93379-6