Long-term clinical outcomes according to initial management and thrombolysis in myocardial infarction risk score in patients with acute non-St-segment elevation myocardial infarction

Purpose: There is still debate about the timing of revascularization in patients with acute non-ST-segment elevation myocardial infarction (NSTEMI). We analyzed the long-term clinical outcomes of the timing of revascularization in patients with acute NSTEMI obtained from the Korea Acute Myocardial Infarction Registry (KAMIR). Materials and Methods: 2,845 patients with acute NSTEMI (65.6 ± 12.5 years, 1,836 males) who were enrolled in KAMIR were included in the present study. The therapeutic strategy of NSTEMI was categorized into early invasive (within 48 hours, 65.8 ± 12.6 years, 856 males) and late invasive treatment (65.3 ± 12.1 years, 979 males). The initial- and long-term clinical outcomes were compared between two groups according to the level of Thrombolysis In Myocardial Infarction (TIMI) risk score. Results: There were significant differences in-hospital mortality and the incidence of major adverse cardiac events during one-year clinical follow-up between two groups (2.1% vs. 4.8%, p < 0.001, 10.0% vs. 13.5%, p = 0.004, respectively). According to the TIMI risk score, there was no significant difference of long-term clinical outcomes in patients with low to moderate TIMI risk score, but significant difference in patients with high TIMI risk score (≥ 5 points). Conclusion: The old age, high Killip class, low ejection fraction, high TIMI risk score, and late invasive treatment strategy are the independent predictors for the long-term clinical outcomes in patients with NSTEMI.