Clinical outcomes in ST-segment elevation myocardial infarction patients undergoing percutaneous coronary interventions later than 48 h after symptom onset

Aims Routine revascularization in patients with ST-segment elevation myocardial infarction (STEMI) presenting >48 h after symptom onset is not recommended. Methods and results We compared outcomes of STEMI patients undergoing percutaneous coronary intervention (PCI) according to total ischaemic time. Patients included in the Bern-PCI registry and the Multicenter Special Program University Medicine ACS (SPUM-ACS) between 2009 and 2019 were analysed. Based on symptom-to-balloon-time, patients were categorized as early (<12 h), late (12-48 h), or very late presenters (>48 h). Co-primary endpoints were all-cause mortality and target lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction, and target lesion revascularization at 1 year. Of 6589 STEMI patients undergoing PCI, 73.9% were early, 17.2% late, and 8.9% very late presenters. The mean age was 63.4 years, and 22% were female. At 1 year, all-cause mortality occurred more frequently in late vs. early [5.8 vs. 4.4%, hazard ratio (HR) 1.34, 95% confidence interval (CI) 1.01-1.78, P = 0.04] and very late (6.8%) vs. early presenters (HR 1.59, 95% CI 1.12-2.25, P < 0.01). There was no excess in mortality comparing very late and late presenters (HR 1.18, 95% CI 0.79-1.77, P = 0.42). Target lesion failure was more frequent in late vs. early (8.3 vs. 6.5%, HR 1.29, 95% CI 1.02-1.63, P = 0.04) and very late (9.4%) vs. early presenters (HR 1.47, 95% CI 1.09-1.97, P = 0.01), and similar between very late and late presenters (HR 1.14, 95% CI 0.81-1.60, P = 0.46). Following adjustment, heart failure, impaired renal function, and previous gastrointestinal bleeding, but not treatment delay, were the main drivers of outcomes. Conclusion PCI >12 h after symptom onset was associated with less favourable outcomes, but very late vs. late presenters did not have an excess in events. While benefits seem uncertain, (very) late PCI appeared safe.