Prognostic value of the admission electrocardiogram in acute coronary syndromes

Context The presence of ischemic changes on electrocardiogram (ECC) correla tes with poorer outcomes in patients with acute chest pain. Objective To determine the prognostic value of various ECC; presentations o f acute myocardial ischemia. Design Retrospective analysis of the presenting ECGs of patients enrolled i n Global Use of Strategies To Open Occluded Arteries in Acute Coronary Synd romes (GUSTO-IIb). Setting Three hundred seventy-three hospitals in 13 countries in North Amer ica, Europe, Australia, and New Zealand. Patients A total of 12 142 patients who reported symptoms of cardiac ischem ia at rest within 12 hours of admission and had signs of myocardial ischemi a confirmed by ECG. On presenting ECG, 22% of patients had T-wave inversion , 28% had ST-segment elevation, 35% had ST-segment depression, and 15% had a combination of ST-segment elevation and depression. Main Outcome Measure Ability of presenting ECG to predict death or myocardi al reinfarction during the first 30 days of follow-up. Results The 30-day incidence of death or myocardial reinfarction was 5.5% i n patients with T-wave inversion, 9.4% in those with ST-segment elevation, 10.5% in those with ST-segment depression, and 12.4% in those with ST-segme nt elevation and depression (P<.001). After adjusting for factors associate d with an increased risk of 30-day death or reinfarction, compared with tho se who had T-wave inversion only, the odds of 30-day death or reinfarction were 1.68 (95% confidence interval [CI], 1.36-2.08) in those with ST-segmen t elevation, 1.62 (95% CI, 1.32-1.98) for those with ST-segment depression, and 2.27 (95% CI, 1.80-2.86) for those with combined elevation and depress ion. An elevated creatine kinase level at admission correlated with a highe r risk of death (odds ratio [OR], 2.36; 95% CI, 1.92-2.91) and death or rei nfarction (OR, 1.56; 95% CI, 1.32-1.85). The ECG category and creatine kina se level at admission remained highly predictive of death and myocardial in farction after multivariate adjustment for the significant baseline predict ors of events. Conclusions The ECG at presentation allows immediate risk stratification ac ross the spectrum of acute coronary syndromes. An elevated creatine kinase level at admission is associated with worse outcomes.