Objective: To compare the effect and safety of early intervention and delayed intervention in patients with non-ST segment elevation acute coronary syndrome.
Methods: In this multicenter randomized trial, patients diagnosed as non-ST segment elevation acute coronary syndrome were randomly assigned to undergo early intervention (coronary angiography ≤ 24 hours after randomization, n = 446) or delayed intervention (coronary angiography ≥ 36 hours after randomization, n = 369). The primary outcome was a composite of death, myocardial infarction or stroke at 180 days. The secondary outcome was death, myocardial infarction, refractory ischemia, stroke or revascularization at 180 days.
Results: Baseline clinical characteristics were comparable between the two groups. Incidence of both primary (9.0% vs. 14.6%, P = 0.01) and secondary which was a composite of death, myocardial infarction or refractory ischemia (14.6% vs. 22.0% P = 0.01) endpoints were significantly lower in early intervention group than in delayed intervention group. Incidence of myocardial infarction was significantly lower in early intervention group than in delayed intervention group (5.2% vs. 10.8%, P = 0.00). Another secondary outcome which was a composite of death, myocardial infarction, refractory ischemia, stroke or revascularization was similar between the two groups (26.7% vs. 30.4%, P = 0.25).
Conclusion: Compared to delayed intervention group, early intervention reduced incidence of myocardial infarction but did not affect the incidence of death, stroke or refractory ischemia in patients with non-ST segment elevation acute coronary syndrome.