Prognostic value of the admission electrocardiogram in patients with unstable angina/non–ST-segment elevation myocardial infarction treated with very early revascularization

Abstract 

Purpose

The goals of this study were to determine if very early revascularization might ameliorate the adverse prognosis associated with ST-segment depression in patients with unstable angina/non–ST-segment elevation myocardial infarction.

Methods

In this prospective cohort study, 1450 consecutive patients with unstable angina/non–ST-segment elevation myocardial infarction were stratified by the presence of ST-segment depression, T-wave inversion, or no changes on the admission electrocardiogram (ECG). All patients underwent coronary angiography and, if appropriate, revascularization within 24 hours after admission. The primary endpoint was all-cause mortality.

Results

During up to 59 months of follow-up, the in-hospital mortality rate was 2.1% (19/895) in patients with no ECG changes, 4% (6/136) in those with ST-segment depression, and 0.2% (1/419) in those with T-wave inversion. The cumulative death rate at 36 months was 8.0% (n = 49) in patients with no ECG changes, 19.9% (n = 18) in patients with ST-segment depression, and 5.1% (n = 13) in patients with T-wave inversion (P = 0.0001 by log-rank). After adjustment for potential cofounders, ST-segment depression (hazard ratio [HR] = 2.2; 95% confidence interval [CI]: 1.1 to 4.6) and T-wave inversion (HR = 0.44; 95% CI: 0.20 to 0.96) were associated with long-term mortality.

Conclusion

ST-segment depression and T-wave inversion on the admission ECG were important predictors of outcome in patients with unstable angina/non–ST-segment elevation myocardial infarction undergoing very early revascularization. In contrast to the considerable mortality seen in patients with ST-segment depression, T-wave inversion was associated with a more favorable outcome.