In-hospital outcome according to the initial management and the "thrombolysis in myocardial infarction risk score" of acute non-ST segment elevation myocardial infarction

Background and Objectives: The current guidelines recommend an early invasive strategy for patients suffering with non-ST segment elevation myocardial infarction (NSTEMI). However, there is still debate about the timing of revascularization in patients with NSTEMI. To analyze the clinical efficacy of the timing of revascularization, we compared the in-hospital clinical outcome of NSTEMI patients from the Korea Acute Myocardial Infarction Registry (KAMIR) between the early and selective invasive therapeutic groups. Subjects and Methods: Between Nov. 2005 and Apr. 2007, 2762 acute NSTEMI patients (mean age=64.6 ± 12.8 years, 1847 males) were enrolled in the KAMIR. The therapeutic strategy of NSTEMI was categorized into early invasive treatment (within 48 hours, Group I mean age: 63.1 ± 13.1 years, 1085 males) and selective invasive treatment (Group II mean age: 66.5 ± 12.1 years, 762 males). The initial clinical status and the in-hospital mortality and morbidity rate were compared between these two groups. The in-hospital outcomes were also compared between the two groups according to each level of the Thrombolysis In Myocardial Infarction (TIMI) risk score. Results: There were significant differences in the mortality and morbidity rate between the groups (6.5% vs. 10.3%, respectively, p<0.001). According to TIMI risk score, there were no significant differences of mortality and morbidity for the low to moderate risk patients (5.3% vs. 7.8%, respectively, p=0.123 for the risk score 0-2, 6.4% vs. 8.7%, p=0.139 for the risk score 3-4). Conclusion: Early invasive treatment improves the hospital outcome for the high-risk NSTEMI patients. The use of abciximab, a low ejection fraction, a high Killip class, a high TIMI risk score and old age are the predictive factors of in-hospital mortality and morbidity.