Myocardial Infarction as the First Clinical Manifestation of Coronary Artery Disease: A Scoping Review

Background/Objectives: Acute myocardial infarction (AMI) remains a leading cause of death worldwide and sometimes occurs as the inaugural presentation of CAD. Studies have been heterogeneous in reporting what proportion this population represents; therefore, we sought to review the evidence of myocardial infarction as the initial manifestation of CAD. Methods: We conducted a scoping review of 25 studies (1979-2021) assessing the prevalence, risk factors, and outcomes of patients who experience AMI as the first clinical manifestation of CAD. Results: Across studies, most found that half of AMI patients present with no prior angina or CAD diagnosis. These patients tend to be younger and have fewer traditional risk factors. Sex differences were inconsistently reported, though some studies suggest that women may be more likely to present with unheralded AMI. Diabetes and hypertension were interestingly more common in patients with known CAD. Patients with unheralded AMI demonstrate a larger infarct size and may have a higher likelihood of adverse cardiovascular events compared to those with known CAD. Conclusions: Our findings highlight a critical gap in the current risk models of CAD evaluation, which are often symptom-based and focused on detecting ischemia, thus failing to detect a significant proportion that present with AMI as their initial manifestation of CAD.