Introduction: Coronary artery disease is a growing global concern, and inflammation plays a significant role in its development. Inflammation is associated with plaque formation, rupture, endothelial dysfunction, platelet aggregation, and thrombus formation. Non-ST-segment elevation myocardial infarction (NSTEMI) accounts for 75% of acute coronary syndrome cases. The inflammatory response tends to increase prior to acute myocardial infarction (AMI) and becomes highly active after AMI. The Aggregate Index of Systemic Inflammation (AISI), a composite of multiple inflammatory markers, is a significant predictor of adverse outcomes in NSTEMI patients and underscores the role of inflammation in AMI. However, existing data do not indicate a correlation between the SYNTAX score (SXscore) and AISI in patients with NSTEMI. Methods: This study included 226 NSTEMI patients who underwent coronary angiography between January2022and December 2023. The SXscore is categorized into low (<= 22) and intermediate-high (>22) groups. The AISI was used to assess systemic inflammation in whole blood. Results: The study included 153 participants with an SXscore <= 22 and 73 with an SXscore >22. Laboratory analysis indicated significantly higher AISI levels in the cohort with an SXscore >22 (p=0.027). Multivariable logistic regression showed that age (p=0.010) and AISI levels (p=0.017) independently predicted the intermediate-high SXscore and the group with SXscore >22, respectively. Conclusion: The AISI, a biomarker, can identify patients with intermediate-to-high SXscore, aiding early risk assessment and triage decisions. Patients with high values require aggressive treatment.