Systemic Biomarkers in Predicting Clinical Outcomes among Patients with Non-ST Segment Elevation Myocardial Infarction: A Systematic Review

Background: The ability to predict clinical outcomes in Non-ST Segment Elevation Myocardial Infarction (NSTEMI) could potentially lead to better risk stratification and treatment management. This systematic review aims to evaluate the predictive value of systemic biomarkers on the clinical outcomes among NSTEMI patients. Methods: A comprehensive search across PubMed, Web of Science and Scopus was conducted, adhering to PRISMA Statement 2020 guidelines. Original clinical studies involving NSTEMI patients with measured systemic biomarkers were considered. Keyword combinations included the following: 'NSTEMI', 'systemic biomarkers', 'clinical outcomes', 'major adverse cardiac events', and/or 'mortality. Results: We included 7 studies in total pooling in 863 participants, with biomarkers such as Syntax score, Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to-Lymphocyte Ratio (PLR), Matrix Metallopeptidase 9 (MMP-9), and Perforin (P), among others. All systemic inflammation (SI) biomarkers were found significantly elevated in patients with high Syntax scores. ROC values for major adverse cardiac events (MACE) ranged from 0.592 to 0.637, and for overall mortality from 0.524 to 0.761. Monocytic MMP-9 mRNA levels were found increased in patients with NSTEMI (0.9 +/- 0.3 relative units (RU)). Positive correlations were found between cardiac troponin I plasma concentrations and the frequency of Perforin-positive cells during the first week after the NSTEMI. Conclusion: Systemic biomarkers, including Syntax score, NLR, PLR, MMP-9, and Perforin, show potential predictive value for clinical outcomes in NSTEMI patients. Their use could aid in early risk stratification and management. However, more large-scale, multicenter studies are warranted to validate these findings.