ST-segment deviation on the admission electrocardiogram, treatment strategy, and outcome in non-ST-elevation acute coronary syndromes. A substudy of the Invasive versus Conservative Treatment in Unstable coronary Syndromes (ICTUS) Trial

Background: We assessed the prognostic significance of the presence of cumulative (∑) ST-segment deviation on the admission electrocardiogram (ECG) in patients with non-ST-elevation acute coronary syndrome and an elevated troponin T randomized to a selective invasive (SI) or an early invasive treatment strategy. Methods: A 12-lead ECG obtained at admission was available for analysis from 1163 patients. The presence and magnitude of ST-segment deviation was measured in each lead, and absolute ST-segment deviation was summed. The effect of treatment strategy was assessed for patients with or without ∑ ST-segment deviation of at least 1 mm. Results: The incidence of death or myocardial infarction (MI) by 1 year in patients with ∑ ST-segment deviation of at least 1 mm was 18.0% compared with 11.1% in patients with ∑ ST-segment deviation of less than 1 mm (P = .001). Among patients with ∑ ST-segment deviation of at least 1 mm, the incidence of death or MI was 21.9% in the early invasive group compared with 14.2% in SI group (P < .01). However, we observed a significantly higher rate of MI after hospital discharge among patients with ∑ ST-segment deviation of at least 1 mm randomized to SI who did not undergo angiography compared with patients who underwent angiography before discharge (10.9% vs 2.4%, P = .003). In a forward logistic regression analysis, the presence of ST-segment deviation was an independent predictor for failure of medical therapy (coronary angiography within 30 days after randomization in the SI group) (odds ratio, 1.56; 95% confidence interval, 1.12-2.18; P = .009). Conclusion: Patients with non-ST-elevation acute coronary syndrome and an elevated troponin T and ∑ ST-segment deviation of at least 1 mm are at increased risk of death or MI, more often fail on medical therapy, and more often experience a spontaneous MI after discharge when angiography was not performed during initial hospitalization.