Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Aug 8;13(3):116.
doi: 10.3390/medsci13030116.

Risk Stratification in Acute Coronary Syndromes: The Systemic Immune-Inflammation Index as Prognostic Marker

Elena Emilia Babes  1   2 , Andrei-Flavius Radu  1   3 , Noemi Adaus Cretu  1 , Gabriela Bungau  1 , Camelia Cristina Diaconu  4   5   6 , Delia Mirela Tit  1   7 , Victor Vlad Babes  2
Affiliations

Risk Stratification in Acute Coronary Syndromes: The Systemic Immune-Inflammation Index as Prognostic Marker

Elena Emilia Babes et al. Med Sci (Basel). .

Abstract

Background/objectives: Inflammation plays a key role in acute coronary syndromes (ACS). The systemic immune-inflammation index (SII), which integrates immune and inflammatory markers, may serve as a valuable prognostic tool. This study aimed to evaluate the utility of SII as a short-term predictor of mortality and major adverse cardiovascular and cerebral events (MACCE) in ACS patients.

Methods: A retrospective analysis was conducted on 964 ACS patients admitted in 2023. SII was calculated from admission hematological parameters. Primary and secondary outcomes were 30-day mortality and MACCE, respectively.

Results: SII levels differed significantly across ACS subtypes (p < 0.001), highest in ST-segment elevation myocardial infarction (STEMI) and lowest in unstable angina. SII was markedly higher in deceased patients (2003.79 ± 1601.17) vs. survivors (722.04 ± 837.25; p < 0.001) and remained an independent predictor of mortality (OR = 1.038, p < 0.001). Similarly, SII was elevated in MACCE cases (1717 ± 1611.32) vs. non-MACCE (664.68 ± 713.11; p < 0.001) and remained predictive in multivariate analysis (OR = 1.080, p < 0.001). Predictive accuracy for MACCE was moderate (AUC = 0.762), improved when combined with GRACE 2, especially in specificity (p = 0.07). In STEMI, SII had excellent accuracy (AUC = 0.874), outperforming neutrophil-lymphocyte ratio and C-reactive protein. SII rose at 24 h and declined at 48 h in STEMI, with a slower decline in MACCE patients.

Conclusions: SII proved to be a cost-effective biomarker reflecting inflammation, immunity, and thrombosis. Elevated SII predicted short-term MACCE and mortality in ACS, with improved prognostic power when combined with GRACE 2. Persistent elevation may signal ongoing inflammation and increased MACCE risk.

Keywords: NSTEMI; STEMI; acute coronary syndromes; biomarkers; inflammation; major adverse cardiac and cerebrovascular events; mortality; systemic immune-inflammation index.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflicts of interest.

Figures

Figure 1
Figure 1
Flowchart depicting patient selection.
Figure 2
Figure 2
Survival curve. Cox regression multivariate analysis.
Figure 3
Figure 3
Kaplan–Meier survival curve in patients with low SII (<564) versus patients with high SII (>564).
Figure 4
Figure 4
ROC curves for (a) SII as a predictor of MACCE and (b) a combined parameter SII and GRACE 2 risk score versus only GRACE 2 risk score as a predictor of MACCE in ACS patients.
Figure 5
Figure 5
ROC curves for (a) SII as a predictor of MACCE and (b) a combined parameter SII and GRACE 2 risk score versus GRACE 2 risk score as a predictor of MACCE in ACS patients treated with PCI.
Figure 6
Figure 6
ROC curves for (a) SII as a predictor of MACCE in STEMI patients and (b) SII as a predictor of MACCE in STEMI patients with PPCI.
See this image and copyright information in PMC

References

    1. Yang Y.L., Wu C.H., Hsu P.F., Chen S.C., Huang S.S., Chan W.L., Lin S.J., Chou C.Y., Chen J.W., Pan J.P., et al. Systemic Immune-Inflammation Index (SII) Predicted Clinical Outcome in Patients with Coronary Artery Disease. Eur. J. Clin. Investig. 2020;50:e13230. doi: 10.1111/eci.13230. - DOI - PubMed
    1. Ralapanawa U., Sivakanesan R. Epidemiology and the Magnitude of Coronary Artery Disease and Acute Coronary Syndrome: A Narrative Review. J. Epidemiol. Glob. Health. 2021;11:169–177. doi: 10.2991/jegh.k.201217.001. - DOI - PMC - PubMed
    1. Piironen M., Ukkola O., Huikuri H., Havulinna A.S., Koukkunen H., Mustonen J., Ketonen M., Lehto S., Airaksinen J., Antero Kesäniemi Y., et al. Trends in Long-Term Prognosis after Acute Coronary Syndrome. Eur. J. Prev. Cardiol. 2017;24:274–280. doi: 10.1177/2047487316679522. - DOI - PubMed
    1. Gur D.O., Efe M.M., Alpsoy S., Akyüz A., Uslu N., Çelikkol A., Gur O. Systemic Immune-Inflammatory Index as a Determinant of Atherosclerotic Burden and High-Risk Patients with Acute Coronary Syndromes. Arq. Bras. Cardiol. 2022;119:382–390. doi: 10.36660/ABC.20210416. - DOI - PMC - PubMed
    1. Libby P., Pasterkamp G., Crea F., Jang I.K. Reassessing the Mechanisms of Acute Coronary Syndromes: The “Vulnerable Plaque” and Superficial Erosion. Circ. Res. 2019;124:150–160. doi: 10.1161/CIRCRESAHA.118.311098. - DOI - PMC - PubMed

LinkOut - more resources