CONGRESS ABSTRACT

Background Despite major advances in reperfusion strategies, late presentation after symptom onset remains common in patients with ST-elevation myocardial infarction (STEMI). Beyond total ischemic time, identifying the clinical and system-related determinants of delayed presentation is crucial to improve patient management and healthcare organization. Methods A scoping review of the literature was conducted using PubMed. Observational studies and large registries reporting predictors, clinical characteristics, system-related factors and outcomes associated with late presentation (≥12 hours from symptom onset) in STEMI patients were included. Results Twelve studies were included, comprising more than 25,000 STEMI patients, of whom approximately 20–25% presented late. Across cohorts, late presenters were more frequently female (35–45%), diabetic (30–40%), and less likely to report typical chest pain (25–40%) compared with early presenters. System-related determinants were consistently reported, including lower activation of emergency medical services, with ambulance use ranging from 30–50%, as well as delays related to rural residence, lower socioeconomic status and inter-hospital transfer. The use of invasive strategies declined markedly beyond 12 hours, with “no PCI” rates increasing from approximately 5% in early presenters to over 20% in very late presenters. Late presentation was associated with higher crude short- and long-term mortality, reaching 15–17% at 3 years. However, data from large contemporary registries suggest that presentation timing alone is not always an independent predictor of mortality after multivariable adjustment, particularly in selected patients undergoing invasive management. Conclusions Late presentation in STEMI affects a substantial proportion of patients and reflects a complex interaction between patient-related and system-related factors. Beyond symptom-to-door time, clinical profiling and healthcare system organization are essential to identify late presenters who may still benefit from tailored invasive strategies in real-world practice.