Acute myocardial infarction (AMI) remains a leading cause of mortality worldwide, highlighting the need for improved diagnostic approaches. While cardiac troponins are the current gold standard, their reliability in early detection and in patients with comorbidities is limited. This review evaluates conventional AMI biomarkers and highlights emerging candidates including non-coding RNAs, cell-free DNA, exosomes, proteins, and metabolites. It also explores the potential of non-invasive samples such as saliva and urine for early detection. After reviewing recent advances in biomarker discovery and detection technologies, this article presents a comprehensive overview of evolving AMI diagnostics. Identifying sensitive and specific biomarker detectable in non-invasive samples has important clinical relevance for improving early diagnosis and guiding prompt treatment. Future efforts should focus on multi-marker strategies, patient-specific diagnostic thresholds, and the clinical validation of novel non-invasive biomarkers.