Clinical implications of a next-day follow-up electrocardiogram in patients with non-ST elevation acute coronary syndromes.
Am Heart J. 2008 Oct;156(4):797-803
Authors: Alkaabi S, Baslaib F, Casanova A, Yan AT, Fitchett D, Mendelsohn A, Nikhil JY, Langer A, Goodman SG,
BACKGROUND: The prognostic value of admission ST-segment changes in patients with non-ST elevation acute coronary syndromes (NSTE ACS) is well established; however, the value of a next-day follow-up electrocardiogram (ECG) is unclear. METHOD: We evaluated ST-depression (ST downward arrow) and Q-wave status on the admission and 24 to 36-hour follow-up ECG in 2,743 patients in a prospective Canadian ACS registry. RESULTS: Of patients with ST downward arrow > or =1 mm on admission (n = 533 [19.4%]), 366 (68.7%) normalized their ST segment on follow-up ECG. Among patients without ST downward arrow on admission (n = 2,110), 97 (4.4%) developed new ST downward arrow at follow-up. Patients with normalized ST downward arrow at follow-up had higher 1-year myocardial infarction (MI) (10.1% vs 5.7%, odds ratio [OR] 1.77, 95% CI 1.12-2.81, P = .015) and death/MI rates (19.5% vs 10.2%, OR 1.69, 95% CI 1.18-2.41, P = .004), respectively, as compared to those who never had ST downward arrow. Patients with persistent ST downward arrow had higher 1-year MI (10.8% vs 5.7%, OR 1.95, 95% CI 1.09-3.51, P = .025) and death/MI rates (25.6% vs 10.2%, OR 1.78, 95% CI 1.13-2.79, P = .013), respectively. In multivariable analysis, ST downward arrow on baseline ECG was an independent predictor of 1-year mortality; however, ST downward arrow on the follow-up ECG did not provide additional prognostic value. There were no differences in outcomes between the 4 different Q-wave status groups. CONCLUSIONS: Although dynamic and persistent ST downward arrow are associated with worse unadjusted outcome in patients with NSTE ACS, there was no incremental prognostic value of a follow-up ECG evaluating ST depression and/or Q-wave status beyond that already provided by the initial ECG together with established prognostic factors.
PMID: 18926163 [PubMed - in process]