Frequency and outcomes of STEMI patients presenting between 12 and 24 h after symptom onset: Late-presenting STEMI

Objectives: To assess the characteristics and prognosis of ST-elevation myocardial infarction (STEMI) patients, presenting between 12 and 24 h after symptom onset, in contemporary regional STEMI systems of care in the United States.

Background: Previous observational studies have been inconsistent regarding the benefit of primary percutaneous coronary intervention (PCI) compared with conservative management for late-presenting STEMI patients and the majority of randomized trials are from the fibrinolytic era.

Methods: Using a two-center registry-based cohort from March 2003 to December 2020, we evaluated the frequency, clinical characteristics, and outcomes of STEMI patients, stratified by symptom onset to balloon time: <3, 3-6, 6-12, and 12-24 h (late presenters).

Results: Among 5427 STEMI patients with available symptom onset time, 6.2% were late presenters, which increased to 11% during the early phase of the Covid-19 pandemic. As symptom onset to balloon time increased, patients were more likely to be older, female, and have a history of hypertension and diabetes mellitus. Late presenters with an identifiable culprit lesion were less likely to be revascularized with PCI (96%, 96%, 95%, and 92%; p for trend = 0.004) and had a longer median door-to-balloon time (82, 109, 107, and 117 min; p for trend < 0.001). In-hospital and 1-year death risks were comparable between late and earlier presenters.

Conclusion: Despite the unfavorable risk profile and longer door-to-balloon time, clinical outcomes of late presenters were similar to those presenting within 12 h of symptom onset.