Prognostic Value of Cardiac Biomarkers in Acute Myocardial Infarction: A Systematic Review and Meta-Analysis.

Acute myocardial infarction (AMI) remains a leading cause of morbidity and mortality worldwide, necessitating effective risk stratification to improve clinical outcomes. Biomarkers, including cardiac troponins, natriuretic peptides, inflammatory markers, and more recently neutrophil gelatinase-associated lipocalin (NGAL), galectin-3 (Gal-3), and microRNAs (miR-208b and miR-499), have been investigated for their prognostic potential. Among emerging biomarkers, NGAL and Gal-3 showed the strongest promise for predicting major adverse cardiovascular events (MACEs) and left ventricular remodeling, while microRNAs correlated with infarct size. However, their comparative value and optimal integration into routine clinical practice remain uncertain. This systematic review and meta-analysis synthesized evidence from 10 studies involving 3,720 participants to assess the prognostic utility of these biomarkers for predicting MACEs, heart failure, and mortality. The pooled correlation coefficient (r = 0.72, 95% CI: 0.61-0.81) reflects the association between biomarker levels and clinical outcomes; correlation was chosen as the summary metric to harmonize diverse effect measures (HRs, ORs, and RRs) across studies. The included studies focused exclusively on patients with AMI (acute phase of coronary artery disease progression), with prognostic aims encompassing both primary cardiovascular events and recurrent events. Subgroup analyses by population type (general AMI population vs. high-risk subgroups such as patients with reduced left ventricular ejection fraction or cardiogenic shock) and prognostic endpoint (mortality vs. heart failure vs. MACEs) revealed consistent associations across strata, although effect sizes were larger in high-risk populations. Cardiac troponins demonstrated stronger associations with mortality (r range: 0.73-0.83), while natriuretic peptides showed stronger correlations with heart failure (r range: 0.68-0.75). Inflammatory markers such as C-reactive protein (CRP) and interleukin-6 (IL-6) were also associated with unfavorable cardiovascular outcomes, underscoring the role of systemic inflammation in post-AMI prognosis. High heterogeneity (I² = 94.51%) was observed, primarily driven by differences in timing of biomarker measurement (admission vs. serial sampling) and endpoint definitions (e.g., all-cause mortality vs. heart failure-specific outcomes). Although emerging biomarkers have shown promise for risk stratification, further validation is required before routine adoption. Improved biomarker integration would most benefit early risk stratification in emergency settings by guiding triage, revascularization decisions, and post-discharge monitoring. Overall, these results reaffirm the importance of cardiac biomarkers in AMI prognostication and highlight the need for future studies to standardize measurement protocols and explore multimodal integration. Future research should focus on developing multimarker panels, applying dimensionality reduction techniques to enhance risk prediction models, and leveraging advanced information technologies to improve patient outcomes.