Fabiele de Lima Righi et al. Gustavo Sugai Paula Araujo Renato Jorge Alves
Abstract
Background:
The systemic immune-inflammation index (SII) and the systemic inflammation response index (SIRI) are inflammatory biomarkers derived from neutrophil (N), platelet (P), lymphocyte (L), and monocyte (M) counts. These indices have been associated with prognostic value in patients with coronary artery disease (CAD) and may contribute to risk stratification in acute coronary syndrome (ACS).
Objectives:
To evaluate the independent association between inflammatory hematologic indices and ACS phenotypes and to explore their relationship with cardiovascular risk factors.
Methods:
This retrospective study analyzed data collected from medical records between July 2022 and July 2023, including 333 patients aged ≥ 18 years of both sexes diagnosed with ACS and admitted to the emergency department of a public hospital in the state of São Paulo, Brazil. Sample was divided into two groups: i) ST-segment elevation myocardial infarction (STEMI) and ii) non-ST-segment elevation myocardial infarction plus unstable angina (NSTEMI+UA). SII was calculated as N × P / L and SIRI as N × M / L. The association between inflammatory indices and ACS phenotypes was assessed using multivariable logistic regression models. Statistical significance was set at 5%.
Results:
Higher values of the inflammatory indices SII (odds ratio [OR], 2.27; 95%CI, 1.66-3.10) and SIRI (OR, 2.92; 95%CI, 2.15-3.96), as well as a history of smoking, were independently associated with a higher likelihood of STEMI diagnosis. Additionally, the STEMI group showed significantly higher values of SII, SIRI, MLR, NLR, and PLR compared with the NSTEMI+UA group.
Conclusions:
Higher SII and SIRI values were independently associated with STEMI diagnosis, which suggests these indices may reflect differences in the inflammatory profile across ACS phenotypes.
