Long-Term Outcomes of Patients With Late Presentation of ST-Segment Elevation Myocardial Infarction.

<bold>Background: </bold>Real-world data on baseline characteristics, clinical practice, and outcomes of late presentation (12 to 48 h of symptom onset) in patients with ST-segment elevation myocardial infarction (STEMI) are limited.<bold>Objectives: </bold>This study aimed to investigate real-world features of STEMI late presenters in the contemporary percutaneous coronary intervention (PCI) era.<bold>Methods: </bold>Of 13,707 patients from the Korea Acute Myocardial Infarction Registry-National Institutes of Health database, 5,826 consecutive patients diagnosed with STEMI within 48 h of symptom onset during 2011 to 2015 were categorized as late (12 to 48 h; n = 624) or early (<12 h; n = 5,202) presenters. Coprimary outcomes were 180-day and 3-year all-cause mortality.<bold>Results: </bold>Late presenters had remarkably worse clinical outcomes than early presenters (180-day mortality: 10.7% vs. 6.8%; 3-year mortality: 16.2% vs. 10.6%; both log-rank p < 0.001), whereas presentation at ≥12 h of symptom onset was not independently associated with increased mortality after STEMI. The use of invasive interventional procedures abruptly decreased from the first (<12 h) to the second (12 to 24 h) 12-h interval of symptom-to-door time ("no primary PCI strategy" increased from 4.9% to 12.4%, and "no PCI" from 2.3% to 6.6%; both p < 0.001). Mortality rates abruptly increased from the first to the second 12-h interval of symptom-to-door time (from 6.8% to 11.2% for 180-day mortality; from 10.6% to 17.3% for 3-year mortality; all p < 0.05).<bold>Conclusions: </bold>Data from a nationwide prospective Korean registry reveal that inverse steep differences in the use of invasive interventional procedures and mortality rates were found between early and late presenters after STEMI. A multidisciplinary approach is required in identifying late presenters of STEMI who can benefit from invasive interventional procedures until further studied. [ABSTRACT FROM AUTHOR]