Context.— Early risk stratification of patients with myocardial infarction is
critical to determine optimum treatment strategies and enhance outcomes, but
knowledge of the prognostic importance of the initial electrocardiogram (ECG)
Objective.— To assess the independent value of the initial ECG for short-term risk
stratification after acute myocardial infarction.
Design.— Retrospective analysis of the Global Utilization of Streptokinase and
t-PA (alteplase) for Occluded Coronary Arteries (GUSTO-I) clinical trial database.
Setting.— A total of 1081 hospitals in 15 countries.
Patients.— From the 41021 patients enrolled in the overall study, we selected those
who presented within 6 hours of chest pain onset with ST-segment elevation
and no confounding factors (paced rhythms, ventricular rhythms, or left bundle-branch
block) on the ECG performed before thrombolysis was administered (n=34166).
Main Outcome Measure.— Ability of initial ECG to predict all-cause mortality at 30 days.
Results.— Most ECG variables were associated with 30-day mortality in a univariable
analysis. In a multivariable analysis combining the initial ECG variables
and clinical predictors of mortality, the sum of the absolute ST-segment deviation
(both ST elevation and ST depression: odds ratio [OR], 1.53; 95% confidence
interval [CI], 1.38-1.69), ECG, heart rate (OR, 1.49; 95% CI, 1.41-1.59),
QRS duration (for anterior infarct: OR, 1.55; 95% CI, 1.43-1.68), and ECG
evidence of prior infarction (for new inferior infarct: OR, 2.47; 95% CI,
2.02-3.00) were the strongest ECG predictors of mortality. A nomogram based
on the multivariable model produced excellent discrimination of 30-day mortality
Conclusions.— In patients presenting with myocardial infarction accompanied by ST-segment
elevation, components of the initial ECG help predict 30-day mortality. This
information should be valuable in early risk stratification, when the opportunity
to reduce mortality is greatest, and may help in assessing outcomes adjusted
for patient risk.