Immediate Compared With Delayed Percutaneous Coronary Intervention for Patients With ST-Segment–Elevation Myocardial Infarction Presenting ≥12 Hours After Symptom Onset Is Not Associated With Improved Clinical Outcome

Background: The role of immediate percutaneous coronary intervention (PCI; door-to-balloon time ≤90 minutes) in patients with ST-segment–elevation myocardial infarction who present ≥12 hours after symptom onset is still obscure. We sought to explore the clinical outcomes of immediate PCI in patients with ST-segment–elevation myocardial infarction depending on presentation time. Methods: Using the Korea Acute Myocardial Infarction Registry, a nationwide prospective multicenter registry in the Republic of Korea, we analyzed data from 5968 patients with ST-segment–elevation myocardial infarction. These patients were classified into the following groups: early presenters (n=5104 with symptom onset-to-door time <12 hours), late presenters (n=599 with symptom onset-to-door time 12–48 hours), and very late presenters (n=265 with symptom onset-to-door time ≥48 hours). The primary outcome was major adverse cardiac events, a composite of cardiac death, any myocardial infarction, and clinically driven target lesion revascularization. Results: In early presenters, immediate PCI was significantly associated with a lower rate of major adverse cardiac events compared with delayed PCI (door-to-balloon time >90 minutes; immediate versus delayed PCI, 8.6% versus 17.9%; inverse probability weighting adjusted hazard ratio, 0.63 [95% CI, 0.56–0.71]). In late presenters, immediate PCI was not associated with better major adverse cardiac events outcomes (13.0% versus 14.8%; inverse probability weighting adjusted hazard ratio, 1.05 [95% CI, 0.77–1.44]). The same trend was found for cardiac death (early presenters: immediate versus delayed PCI, 5.6% versus 14.3%; inverse probability weighting adjusted hazard ratio, 0.55 [95% CI, 0.48–0.64]; late presenters: 9.9% versus 9.8%; inverse probability weighting adjusted hazard ratio, 1.25 [95% CI, 0.86–1.82]). Very late presenters also showed the same trends as late presenters. Immediate PCI was an independent predictor of major adverse cardiac events in early presenters but not in late presenters. Conclusions: Immediate PCI, defined by time door-to-balloon time ≤90 minutes, for patients with ST-segment–elevation myocardial infarction who present ≥12 hours after symptom onset is not associated with improved long-term clinical outcomes as compared with delayed PCI (door-to-balloon time >90 minutes).